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dBFA software suite USER MANUAL

1. 4 6 11 9 Notes Start MATLAB The first script activates the application if MATLAB is not already active The following scripts will use the same proceedings You have to use the matlab exe Automation command in your Windows shortcut if you want to start MATLAB before dBFA it starts Started in this way dBFA will use the MATLAB application already activated MATLAB recording as ActiveX server Start the matlab exe RegServer command the first time Using batches Thanks to the dBFA batches you can study systematically your signals with the MATLAB function m At the end of the batch you get you results in dBFA if needed PAGE 128 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 12 Tachometry These operators are used to carry out various post processing operations on signals coupled to speed profiles or to a dynamic acquisition channel of the tachometric signal order extraction order extraction with phase information order filtering on a time signal detection of cycle defects 4 6 12 1 Order extraction operator EXO_ 0 This operator performs order extraction from a speed channel and a measurement channel selection of the method constant resolution in order or in frequency EXO_0 Order extraction x erator Sel i i i Operator Setup In the Configuration tab the following analysis parameters may N Tracked orders be defined Add T Tracked orders Enter the orders to extract from
2. gt Display of phase or imaginary part oe tte LEIT ee dee Tee ee err et ft AA Cee rere AA Creer ere rer TETTETETT gt pewsi2 10 14 50 000 05000 Scroll bar for a multispectrum view with time indicator The toolbar in the graphic window fives access to the following operations Cancel zoom Zoom function is accessible by E pressing on the Shift key and selecting the area with i Define Edit data parameters for display the mouse Place cross cursors in corners Cursor synchronisation for the selection of a specific G working area Levels in dB are calculated with respect to the international system reference values Reference values can be modified as well as the physical units using the Preferences Units management menu See Section 11 1 3 3 5 1 Data calculation parameters for display Use or Nyquist Nichols Parameters to set calculation parameters A dialog box including several tabs is displayed on screen These tabs are used to define the parameters described hereafter Fised by default To set the default parameters check the AS box and click on OK Apply or Apply to all Data tab Display parameters setup 2222n xj Select the appropriate representation the polar view corresponds Data to the Nichols representation and the complex view to the Nyquist representation Polar Comples Spectral units M Optimize a Select physical units Dynamic Lin or
3. PAGE 179 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The table shown below gives a list of old datafiles that can be imported in dBFA 1 x aE SIG dBARIA Signal recordings audios 1 x Files DAT dBIMPULS Impulse responses Files WAV Signal recordings audios in Windows format Stay A E Files FB Narrow band spectra catalogue CBFA Files FC Broad band spectra catalogue CRTA OBESI Files NOC Broad band spectra catalogue 1 Nth octaves ety GELLER Files LWI DBFA Sound power measurements according to 1509614 Files LW and WLW INTAC Sound power measurements according to 1509614 Files LOG Files in SONY PC Scan II format EC Scan I software Files MP3 Any program handling MP3 Files in MPEG Layer III format format Files HDR Files in TEAC format TEAC Files in nSoft format Files UFF Any program handling UFF Files in Universal File format format I a X a X a X X X Files SIG ASP COH TRF TF ISP Laxade Files in Lexade format Fichiers NTR Files NetdB dBRecorder Files Opera 11 2 Import WAV or NTR format To import a WAV or NTR file dBFA suggests to split channels if the need arises knowing that one item cannot exceed 500Mo and that time display y F T of item of size gt 30Mo is not recommended Example e Optional split channels are 25Mo storable and displayable e Necessary split channel are 1024Mo A split in 3 items is necessary 500 500 24 To display channels a spilt in 35
4. 1 H NE 20108 0 ref H gt is the modulus of the frequency response function The phase of the result expressed in radians is equal to The opposite of the phase of cross spectrum Gxy or the phase of Gyx Coherence If x is the input signal and y the output signal of the process the coherence is defined based on the cross spectrum Gxy and the autospectra Gyy and Gyy If Y is the coherence then y Gxy Gxx Gyy The coherence is a dimensionless number ranging from 0 to 1 Other method for determining the frequency response function transmissibility calculation By raising the initial expression of the frequency response function H f to the power of two a new expression is obtained LH 5 OWY This expression does not contain any phase information Gxx The modulus of the result expressed in dB is equal to H OS 2 10log 5 ref Hal is the modulus of the frequency response function LU This method for the determination of the frequency response function is not developed in dBFA PAGE 101 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 4 2 Cross spectrum G21 Operator FBG21 This processing produces from a cross spectrum the cross spectrum defined as its associated complex The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Autospectrum Chan
5. Overall level Specific Loudness Psychoacoustic criteria Ea Echogram Evolution of psychoacoustic criteria Andina hd Comments Pepchoacoustic criteria Kaa Cancel 1 List of available processings it shows all the types of processings compatible with the active script The same operator can be used several times with different parameters to process the same items 2 Designation give a name to the script A user defined name can be specified 3 Set of active processings currently part of the script These operators will be activated to analyse independently the same set of items when running the script 4 Edit the parameters of the selected operator in the list of available processings Each operator shows its own configuration dialog box 5 Comments describing the operator selected in the available processings list If an operator from the active processings list is selected the comment field shows the type of the operator gt gt 6 Key gt that allows adding an operator into the active processings list Different operators of the same type may be added the user may for example define a multispectrum analysis in third octave band with different time steps in the same script A generic name for each operator is given by default 7 The key remove allows the user to remove an operator from the list of the active processings Once the list of active processings has been defined edi
6. PAGE 173 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 3 Communication interface Find in this paragraph the electrical drawings that indicate which pins correspond to input and output contacts of a generic remote control 10 3 1 For a RS232 9 pin serial port male connector on the PC 5 Ground 4 Ouput 1 6 Input 2 8 Input 1 7 Output 2 Input contact n 1 Ping Input contact n 2 p Pin6 Output contact n 1 Output contact n 2 The generated output signal from a RS232 serial port varies from 9V or 12V lower state to 9V or 12V higher state for a current of 5mA In most cases an input remote control requires a 9V power supply for the push key This voltage is not supplied by the RS232 interface A solution is to generate an output signal on the RS232 interface output contact always activated and to power supply the push key with it or to use a capacitance network or a battery PAGE 174 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 3 2 For SYMPHONIE digital inputs outputs female MiniDyn connector 6 Output 1 5 Output 2 4 Input 1 3 Input 2 2 5V 220 Ohm Ny Shield Ground Input contact n 1 Input contact n 2 Output contact n 1 Output contact n 2 Signal 5V 20mA The generated output signal from the MiniDyn connector varies from OV lower state to 5V higher state for a current 20 mA Pin 2 of the MiniDyn connector always supply 5V 2
7. Selection of the channel to display PAGE 160 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The following operations are available from the Action toolbar in the order extraction window Set processing parameters Launch processing Transfer selected elements from PM session to batch elements to Stop processing process View Edit current batch elements to process View speed tachometric channel Discard current results View signal oscilloscope Transfer results to measurement session Refer to Section 9 2 4 for a detailed description of the analysis process 9 1 2 Analysis set up All these functions are available from the vertical action toolbar in the measurement window 9 1 2 1 Batch window elements to process ae Use Actions Edit F8 to manage the list of Signal and Speed profile items to process in the order extraction module of dBFA To be valid all items should be inserted in the batch in the following order If grouping by two put one Signal item and then a Speed profile item If grouping by three put two Signal items and then one Speed profile item Always put Signal items before Speed profile items To save time select items in the active session one by one in the right order by holding the CTRL key down and insert all elements in the batch at the same time The number of items remaining to be processed is displayed in the title bar Use this icon to import Signa
8. X1 In the Configuration tab the following analysis parameters may Operator Setup be defined Esport directory gt gt d 01dB Stell Campagnes z Export directory z Select a directory on the hard disk where to export data Foot Index The button is used to browse the hard disk and search for a specific directory data flow rate in kbytes sec 120 Root Index To optimize the gain before convers Select the root name from which each record will be exported Exported records will be named root_index_number MP3 IM Save the result Annuler In the above example the first exported record is named Demo1 MP3 the second Demo2 MP3 and so on The index number is a way not to overwrite existing records previously exported in a directory In case of a multiple exportation batch the element selection number will be indicated in the filename Timing of the data flow Select the rate for the MP3 files in Kbytes sec by default 128 Kbytes sec The lower the rate the smaller the created files but possible quality loss The Operator tab provides a detailed description for the operating of this type of processing and can be used to modify its name Default script Defaultname MP30 Active for Signal families PAGE 118 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 9 Operations on overall levels From the time history of an overall quantity it is possible to compute an histogra
9. Define gain an threshold parameters Start audio record option Perform an automatic gain adjustment i autorange Show hide overload bar Start acquisition Show hide information table Spee PAGE 144 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The display type and the display parameters of the active curves are controlled using the horizontal toolbar je it Select curves to display Select curve layout type Perform a Y axis autoscale for all curves Define Y axis parameters El a a mu E El Select overall levels to display Select spectral units display Harmonic cursor parameters Integration Differentiation of displayed spectra PAGE 145 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 2 Measurement set up All the functions described below are accessible from the command toolbar of the measurement window 8 2 1 Cross functions Use the command Config Cross function to define the acquisition of cross spectra and transfer functions between active measurement channels The following dialogue box appears This dialogue box allows the user to activate or not the calculation of cross functions during acquisition and gives access to the transfer functions coherence as well as the computation of sound intensity and mean pressure level spectra The option 1 gt 2 activates the cross function calculation from channel 1 to channel 2 En When cross function computation is not activ
10. A complete description of how these different elements interconnected Is given in the getting started manual delivered with your system PAGE 11 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 ACQUISITION amp ANALYSIS WITH DBFA 2 1 Overview of the software package principle of operation dBFA suite allows the user to perform data acquisition and analysis at the same time There is a sequence of steps that the user should follow This will lead not only to successful measurement but also to rapid familiarity with the software The flow diagram below describes the overall structure of dBFA suite software package ACQUISITION i ANALYSIS Hardware dBRTA Configuration and System calibration calibration REQUESTS SORT DATA Editions of requests Execution of requests OFF LINE PROCESSING FUNCTIONS Spectral analysis spectrum operations dBRTA REAL TIME digital filtering transfer functions ACQUISITION po psychoacoustics criteria etc dBFA REAL TIME 1 n octave spectra po Computation server script analysis ACQUISITION Narrow band po Batch processing for data of the same spectra type Transient mode poi Sound intensity Order analysis pi DATAFILE MANAGEMENT Sound power po ISO 9674 Import 16 or 24 bit datafiles SIGNAL po Export signals and results at various RECORDING E formats ii Results edition print copy paste Audio and or tachametric MESUREMENT SESSION DATAFILE CMG Data storage on hard disk
11. DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 9 2 Percentile Operator Pxx This processing is a statistical calculation over the time history of overall levels allowing for the calculation of the level reached or exceeded during x of the time either over the whole time history or over a window size to define The dialog box shown below is displayed on screen Pxx_0 Percentile i x Operator Configuration In the Configuration tab the following analysis parameters may Percentile ji z be defined Window length f j Percentile Enter the statistical index to calculate Overall value e Window size length of the calculation window which is going to move point by point Overall value Check this box to obtain an overall index over the whole time history Save the result Annuler The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name Px O y O History of an overall level Apply to one item only Results family Overall level or history of an overall level PAGE 120 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 10 Room Acoustics An operator is especially dedicated to room acoustics applications From an impulse response acquired by MLS mode or by classical impulse technique an echogram filtered in octave bands or third octave bands can be computed OA specific operator used
12. ID dBFA nom name of the variable ID comment string fe sampling frequency unite unit string Result Example audio m file on CD ROM q pra 75 a function audio ID nom fe unite Ae dBID163 figure nb size ID 0 15 t 1 1 nb 1 vect_t t fe 01 plot vect_t real ID xlabel Time 0 05 ylabel unite title nom mE 4 6 11 3 Type GLOBAL Syntax function xxx ID nom periode unite ID identifier of the variable dBID n ID dBFA nom name of the variable ID comment string periode period time step unite unit string Note ID is expressed in physical units and in energy Result Figure No 1 Iof ES File Edit Window Help function leq ID nom periode unite dBIDG4 figure ul nb size ID t 1 1 nb 1 1 ID nb 1 1 ID nb 1 vect_t t 1 periode stairs vect_t 10 log10 ID 2e 5 2e 5 xlabel Time s yunit sprintf dB s unite ylabel yunit title nom Example leq m file on CD ROM PAGE 125 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 11 4 Type BROAD BAND SPECTRUM Syntax function xxx ID nom fe unite ID identifier of the variable dBID n ID dBFA nom name of the variable ID comment string periode period time step imin ISO index of the min band partial fractional octave 1 3 6 12 24 48 unite unit string Note ID is expressed in physical units and in energy Example fc m file on CD ROM Result Figu
13. This analysis results in a low pass filtered time signal Butterworth even order from 2 to 30 The following dialog box appears on screen LOW O Low pass filtering In the Configuration tab the following analysis parameters may be defined Operator Configuration Notification High cut off frequency Hz fi 414 21 Filter order 20 High cut off frequency define the cut off frequency in Hz e e Filter order Select the Butterworth filter order between the following values 2 4 6 8 10 12 14 16 18 20 22 24 26 28 and 30 The filter order defines the octave fall off rate dB octave and therefore the effectiveness of the filter The greater the filter order the greater the attenuation of high frequency bands Iv Save the result Annuler Low pass filters remove components with a frequency higher than the specified cut off frequency with an octave fall off rate dB octave depending on the filter order The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name LOW_0 Activefor Si Only applies for one item Signal Impulse Response families Family of the result Signal Impulse Response families PAGE 80 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 2 High pass filtering Operator HIGH This analysis results in a high pass filtered time signal Butterworth
14. e Signal segments Number of lines Save the result Annuler a Averaging Define the number of elements to average before speed calculation Slope definition Define the signal slope for impulse detection Tracked orders Use this table to add delete or modify orders to extract Orders may be non integers Tracking parameters rpm Define either the speed interval between two FFT spectra calculation in that case enter the Input minimum and maximum speed for analysis or the time interval in that case enter the minimum and maximum time for the analysis Strategy Indicate whether it is a run up Increasing or a run down Decreasing Block Synchro Indicate if the speed used to date the spectrum is that at the beginning at the middle or at the end of the analysis time block Analysis Enter the bandwidth in Hz as well as the number of lines for the calculation The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Phase order extraction Default name _ OAF O SO Signal family Trigger family Items should belong to the same measurement Result family Complex spectrum Overall RPM Measurement RPM Signal PAGE 130 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 12 3 Order extraction by successive levels Operator EOP_MULT This processing carries out from a speed profile channel and a measurem
15. requiring 2 Signal items for input a transfer function group of 3 relevant items or an averaging etc If the number of items to process is not a multiple of the group size the last items becomes inactive in the batch it will not be processed The script server lists all available scripts to process batch items Driver Batch DEFA32 Signal analysis MATLAB Communication Export Mo operation in progress The title bar should read Driver dBFA batch Select the processing to perform on each group in the batch Refer to Chapter 4 2 for more information on the operation server Launch processing PAGE 136 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The operation window is as follows Driver Batch DBFA32 Ioj x Signal analysis LEG_0 from Batch DBFA32 3 100 The progress of the processing on each item is displayed along with its origin target session and its identification number in the session The number of items remaining to process is listed in the title bar The batch may be interrupted at any time by acting on script server A A Ds Interrupting P and aborting mal have the same consequence the batch processing is definitively stopped Calculated items are automatically added to the session Working on several sessions A batch may contain items originating from several sessions in which case a source session must be selected when importing item into the batch
16. Fast Min Time history of the minimum Fast values over the item duration Fast Max Time history of the maximum Fast values over the item duration Slow Slow integration of the elementary short Leq Slow Min Time history of the minimum Slow values over the item duration Slow Max Time history of the maximum Slow values over the item duration Impuls Impulse integration of the elementary short Leq DO OOOO O DODO Impuls Max Time history of the maximum Impulse values over the item duration E From a multispectrum These operators allow the user to perform a frequency recombination over a user defined frequency range with or without frequency weighting in order to calculate the time history of an overall level frequency channel overall level Loudness etc These processing functions apply to multispectra in narrow bands broad bands and Bark bands PAGE 107 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 6 1 Overall level Operator LEQ This analysis results in a short Legs time history of the time signal Frequency Lin A B C and time Leq Peak Fast etc weightings can be applied The following dialog box appears on screen LEQ O Overall level Operator Configuration Notification Time step jo z f 25 mz Frequency weighting Time weighting Save the result Annuler In the Configuration tab the following analysis parameters may be defined Time step This is the integration duration used to
17. O select and define parameters for the signal to generate Set the general output level This control is active during emission so that the general volume can be adjusted at any time The 0 dB value corresponds to the maximum amplitude that can be generated by a sound card without saturation according to the model Real time display of the shape of the generated signal of the time elapsed and of the generator status O Generator control bar m 4 launch emission for a limited time or not according to O z pause before a possibly resuming emission 5 a stop emission s launch emission for an infinite time regardless of the parameters PAGE 187 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Define a time limit for the emission Check the Limited time box and enter a time in ms O Select the output peripheral device PC sound card or acquisition platform and the number of channels to use 11 8 2 Generating white noise To generate a white noise click on the White noise tab White noise Pink noise Sine LFM WAY file The gain is the only parameter that can be set for the generation of white noise A gain of O dB corresponds to the maximum amplitude that can be generated by a sound Gain dB BE card without saturation depending on the model Once signal parameters are set use 4 to launch the emission 11 8 3 Generating pink noise Click on the Pink noise tab o generate pink noise White noize Pink nois
18. Signal Impulse Response families Family of the result 4 6 2 13 Gain optimisation GAIN This processing amplifies time signal DAC data in order to optimise for example the replay level The physical level remains unchanged This optimisation can be automatic or manual according to a level defined by the user The manual optimisation Is useful to compare signals The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name GAINO CCSS Activefor Signal Impulse Response families Applies for one item only Family of the result Signal Impulse Response families 4 6 2 14 Undersampling Operator DECIM This analysis results in an undersampled time signal fixed by the user A low pass filter Butterworth order 20 ensures anti aliasing the undersampling ratio varies between 2 and 50 The following dialog box appears on screen C in the Configuration tab the following analysis parameters may be Operator Configuration Notification defined Required frequency range Hz 1414 21 E Required frequency range define the maximum frequency of the Fiter order a A audio event after undersampling Slope dB per octave 120 It is recommended not to undersample audio files below 2000 Hz unless source recognition by playing back the file is unimportant The Operator tab gives an overview of this type of processing f
19. Source session window This selection is repeated for each importation using At the end of the processing a Target session window is displayed in order to select the session to which all items will be exported The batch being a way to automate a processing selecting a target session will not disturb the current calculations All calculated items in a batch will be exported to a single session PAGE 137 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 6 MEASUREMENT HARDWARE CONFIGURATION This chapter concerns only intensity and Sound power 1509614 modes Hardware specification and settings are required before any measurement The Hardware configuration option is found under the Acquisition menu of dBFA main window This dialog box see below features various tabs Hardware Peripheral is used to define which hardware elements are used to perform an acquisition hardware peripheral transducers calibrators active channels Remote control is used to define and configure a remote control object this tab is displayed only if the file DBCD32 INI is present in the 01dB Metravib program files directory Phase correction is used to select a sound intensity probe calibration data file file extension AU and Robot tab is used to configure the use of a rotating arm for example Hardware configuration Configuration file Hew Open Save ag From the hardware peripheral tab define Name D 01dB 324Gb 4034cw h
20. USER MANUAL gb_dBFA NUT 043 A 4 6 2 4 Cut band filtering Operator CUT This analysis results in a band stop filtered time signal Butterworth even order from 2 to 30 The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined CUT_0 cut band filtering Low cut off frequency define the low cut off frequency in Hz Operator Configuration Notification Low cut off frequency Hz 707 11 High cut off frequency Hz 414 21 Filter order 20 High cut off frequency define the high cut off frequency in Hz Filter order Select the Butterworth filter order between the following values 2 4 6 8 10 12 14 16 18 20 22 24 26 28 and 30 Slope dB per octave The filter order define the octave fall off rate dB octave and therefore the effectiveness of the filter The greater the filter order the greater the attenuation of low and high frequency bands Iv Save the result Annuler Cut band filters remove components whose frequency lies in the range between the low cut off frequency and the high cut off frequency with an octave fall off rate dB octave depending on the filter order The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name CUT_O Activefor Signal Impulse Response fa
21. and holes The beginning of the window may be applied to the starting date and time of the signal study zone Zeros before and after the signal of user defined duration may also be added in order to extract or select a portion of the signal Once the time window has been defined the user may save it into a catalogue of pre defined window in the INI of the application software This is an important feature when performing the same data processing operations See paragraph 3 3 1 for more information on how to define a study zone for a time signal The following dialog box appears on screen In the Configuration tab define the specific weighting window Liste of sections that compose the weighting window Graphical display of the window being created WIN_O Windowing E Add a section Operator Configuration Notification Edit the parameters of the section selected in Start me Quration me All mz Type Add i 0 00 1000 00 1000 00 Hanning Sia 3 2000 00 3 lectangular 4 r Remove the section selected in the list Delays Define pre and post delays ey before and after the window Pre sd List of user defined windows that have been saved in the application software Save the result OF Annuler The operating process to configure the operator is given below 1 5 Define a study zone for the signal under investigation and write down the duration of each section for wh
22. any type of data All noise and vibration data acquired as well as any analysis result are saved in a database called a measurement session datafile with a CMG extension The procedures for each type of measurement as well as each data processing operation are described in the following paragraphs The stages common to each type of measurement are also described Each procedure is then described in details in the different chapters of this manual PAGE 12 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 2 Measuring with dBFA Since dBFA 4 6 real time measurement except intensity measurement are performed in the new real time modules Please refer to ABRTA user manual available on the installation CD 2 2 1 Common steps Intensity mode Sound Power These steps are necessary only for Intensity ans Sound Power measurement L Stage 1 Set up of the measurement chain Connection of the hardware elements definition of their characteristics in the database utility dBCONFIG set up of the signal conditioning options of both the transducer and the hardware peripheral Refer to the installation manual delivered with your system for more details UU Stage 2 Selection of acquisition hardware one or more transducer calibrator pair Choose Acquisition Hardware Configuration Select the acquisition platform and associated signal conditioning options the correct transducer and calibrator pairs etc UU Stage 3 Calibrat
23. dBFA v 4 9 Frequency analysis software suite and much more User manual supportO01db metravib com www 01db metravib com 2 0033 0 4 72 52 47 52 01dB Head Office 200 chemin des Ormeaux F 69578 Limonest Cedex FRANCE T 33 4 72 52 48 00 33 4 72 52 47 47 Ju 01dB do Brasil Rua Domingos de Morais 2102 Sala 11 1 Andar Vila Mariana 04036 000 Sad Paulo T Ju BRAZIL 55 11 5579 6460 55 11 5579 6610 01dB Metravib Asia Pacific Room 601 Beijing International Club office building 21 Jianguomenwai Avenue Chaoyang District Beijing 100020 ARNA ARABIA AREOLZ 100020 86 10 85322300 extension 111 86 10 8532 4801 yu The specifications are subject to change without notice SYMPHONIE Is a registered trademark of 01dB MICROSOFT Is a registered trademark of the Microsoft Corporation Windows 2000 and XP are trademarks of the Microsoft Corporation TABLE OF CONTENTS gb_dBFA_4 9_user_manual doc Updated on july 2008 PAGE 4 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A TABLE OF CONTENTS 1 DESCRIPTION OF A 01DB METRAVIB PC BASED MEASUREMENT CHAIN o coccccocococonconornnonononennnanas 9 lel INTRODUCTION 2 Sa 9 1 2 GENERAL DESCRIPTION ir A O AE A O E A Os 10 1 3 INDUSTRIAL APPLICATION Ss ER O a O eas 11 2 ACQUISITION amp ANALYSIS WITH DBA ivisscscciiicicsciciecccscedennces ia wincendedeewdsnnesn
24. reactive Default script Restrictions Apply for one item only Must be a multispectrum Family of the result Autospectrum Intensity active free field reactive PAGE 97 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 3 4 Integration Derivation Operator FBID This processing integrates or derives an autospectrum or a cross spectrum acceleration velocity and displacement The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined FBID_O Integration 7 Derivation Operator Configuration Notification Channel 1 Channel 1 Use this field to integrate derive autospectra and the first channel of cross spectra Integrate Derivate I 1 1 I I I Dervate 1 times Move the cursor to the left to integrate the spectrum once first notch twice second notch or three times third notch Channel 2 Move the cursor to the left to derive the spectrum once first notch twice second notch or three times third notch Integ Derivate p Integrate 1 times Channel 2 Use this field to integrate derive autospectra and the second channel of cross spectra e Save the result Annuler The table shown below lists the different possibilities of integration and derivation as a function of the physical unit of the data item Channel 1 Channel 2 Data items families Integration Derivation Integration Derivation mws x x
25. same physical units time basis references type of data If autospectra same physical units references band width or resolution narrow bands time basis type of data Family of the result Signal autospectrum Leq Leq Peak Slow Fast etc eo Loudness levels cannot be added PAGE 104 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 5 2 Subtraction Operator MOINS This processing subtracts all the selected quantities The user may choose either to perform an algebraic or logarithmic subtraction The following dialog box appears on screen MOINS_0 Subtraction Coenai ficati l Operator Configuration Notification In the Configuration tab the following analysis parameters may be defined Arithmetic Algebraic rule Amplitude 40 dB 40 dB 80 de Energy 40 dB 40 de 80 de Algebraic rule Select the algebraic rule for an algebraic subtraction of data items Amplitude 40 dB 40 dB 46 dB Eney A0 neta AdE Logarithmic rule Select the logarithmic rule for an energetic subtraction of data items F Ignore erroneous values e Save the result Annuler If the box Ignore erroneous values is ticked frequency bands that present erroneous values are still computed There are not computed no value if the box is not ticked The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default
26. the spectrum values are listed over the complete frequency range of acquisition nnuler Appliquer Appliquer 4 tous Fixer par d faut Data tab x Frequencies Data Overall levels DenamictdB a In this tab select if the data should be listed in physical units Spectral units Weighting Dynamic Lin or Log or in decibels dB Lin y Then select the required spectral unit RMS or PWR for broad band spectra as well as frequency weighting to apply to the spectral data values nnuler Appliquer Appliquer tous Fixer par d faut Refer to paragraphs 11 3 and 11 4 for a detailed list of the frequency weightings and spectral units available in ABFA Overall levels tab Display parameters setup x Frequencies Data Overall levels In this tab select the overall levels to compute according to a given W Lin syara level batizar suzo frequency weighting displayed in a list T Uses in overall level x bin fo no Hg Overall levels are then displayed at the bottom of the table of results He We Wh zi Annuler Appliquer Appliquer 4 tous Fixer par d faut Refer to paragraphs 11 3 for a detailed list of the frequency weightings available in dBFA PAGE 47 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 5 Description and selection of columns in a measurement session window Use the command Datafile Columns to select the columns that
27. the two LEDs blink It means that the system waits for a decision Validation of the measurement by the blue button Repetition of the measurement by the grey button whatever the choice the system waits for another measurement start action for the same measurement point if the last acquisition has been eliminated for the next measurement point if it has been validated The Red LED indicates a possible overload during acquisition O Perform the measurement again for each point PAGE 177 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 APPENDICES 11 1 Importing datafiles For users that evolved from a 01dB Metravib measurement system in a DOS version or Windows 16bit version to the 32bit software versions it is possible to import data files to the new format Use the command File Import from the adequate software package Ouvrir Look ir E dEFA In dBFA the dialog box shown aside appears on screen al Select the adequate folder on the computer hard disk where the files to import are located then click on the Open key a8 Referenc tb The data is converted to the new datafile format A new measurement session is created to store the data or the File name Demo tb Open a 6 MES data is stored into a measurement session already opened Files of type Narrow band files fb Cancel Nth octave band files noc Signal files sig dB Impulse files dat All files
28. 1 Bruit Blane Original 2 Signal Instantaneous Lin CUT_O 05 10 00 03 16 45 5851 1 22050 Paj O O0 1 Bruit Blanc coupe bande og 10 Signal Instantaneous Lin SAMPL_O 05 10 00 03 16 45 5851 1 51200 Pa O O 1 Bruit Blane Original PAGE 54 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 7 Result exploitation and customisation In dBFA it is possible to print directly a data plot and or a result listing and to export the results as graphics or values in standard office spreadsheet and word processor software for further processing and result presentation The user can also customise the way the data is displayed in the software 3 7 1 Printing results Using the commands of the File menu results can be directly printed by dBFA if a printer is connected to the computer of course Use the command File Print CTRL P to display the Print dialog box Specify which pages should be printed the number of copies and the printer driver to use as well as other parameters print quality etc Print K Ei dBFa32 Cmg Exemple CMG fx Printer Imprimer Suivante Er c dente Deux pages Zoom avant Name OKIPAGE 16n Properties Status Default printer Ready Type OKIPAGE 16n Where Graveur p200 okipage OKIPAGE 16n on Graveur p Properties Comment Imprimer Papier Image Filigrane A propos de m Print range Cop Magasin papier Ma asin 1 All N
29. 4 6 1 3 Narrow band Cross spectrum Operator FBG12 This analysis results in a narrow band cross spectrum with time history capability narrow band multispectrum and frequency zoom The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined FBG12_0 Cross spectrum FFT Window Choose the FFT window for the analysis The following windows are available Rectangular Hanning Hamming Kaiser Bessel and Flat Top Operator Configuration Notification Frequencies Window Overlap Hanning 50 Overlap Choose the overlap factor for the analysis amongst the following quantities 0 25 50 and 75 Band 20000 000 Lines During a FFT analysis the overlap factor represents the percentage of samples that are used simultaneously in two adjacent data blocks a 10000 000 FOOO 000 15000 000 12 500 0 080 a Max frequency Select the maximum frequency of the analysis e Multispectra ZZ cH The pass band defines the maximum frequency of the analysis A scrolling list indicates the available maximum frequencies Iv Save the result Annuler Lines Select the number of lines for the FFT analysis amongst the values displayed in the list 101 201 401 801 1601 or 3201 The higher the number of lines the higher the frequency resolution FFT zoom This group allows the user to define the parameters of a FFT zoom The zoom allows th
30. 6 Cycle defect operator This operator is used to characterise cycle defects with respect to a reference tachometric channel and to calculate statistical magnitudes on amplitudes versus speed xj In the Configuration tab the following analysis parameters may be defined Operator Setup Tracking filter order Enter the order of the low pass Tracker filter order H fie tracking filter as saldos Tracking parameters Enter the speed range to analyse Step 10 Min 500 Max eooo as well as the analysis step in rpm Strat l i j TO rategy Increasing E Strategy Indicate whether it is a run up Increasing or a run down Decreasing The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the h Save the result Annuler operator Default script Signal analysis Default name ACY_O Activefor Signal Speed profile families Items should belong to the same measurement Result family Signal ISSO PAGE 133 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 5 BATCH PROCESSING 5 1 Overview This chapter deals with the new capability of 01dB Metravib software packages to launch a batch processing for a set of data items For example if the user wishes to apply the same analysis script for a set of signal items contained in a measurement session file it is possible to define a set of input quantities and to apply the script automatically input
31. 70 88 Cmg Exemple CMG Date Location Comment Calibration Study Selection Iert In the Location tab edit the comment relative to the location of ES Channel 2 the measurement channel a In the Comment tab edit the comment relative to for example the measurement conditions 3 2 6 3 Editing of items level conversion Modification of 69 70 88 Cmg Exemple CMG Calibrati a i Date Location Comment Calibration Study In the calibration tab define a calibration adjustment for the selected data items Selection de a a 70 Level conversion 34 00 A calibration level conversion in decibels is applied globally with a resolution of 0 01 dB In 95 00 de Restore original level value Click on the key Restore original level value to cancel the level correction PAGE 24 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 2 6 4 Editing of items study zone Modification of 69 70 88 Cmg Exemple CMG Date Location Comment Calibration Study stat 09 12 1998 13 38 20 354 Ear oc En 09 12 1998 13 38 20 486 Complete study Selection In the study tab select the study zone for any subsequent analysis Click on the Complete study key to select the complete duration of the data item for an analysis 3 2 6 5 Autospectrum type or Signal type Modification of 0 1 2 test cmg Date Location Comment Calibration Study Type Informations In the T
32. NUT 043 A 1 3 Industrial applications To perform sound and vibration measurements with a 01dB Metravib PC based measurement chain this is the list of the hardware elements required This list is non exhaustive and may vary from application to application Transducer unit dual channel measurements in option Type I or Type 2 condenser microphone pre polarised externally polarised Associated preamplifier It should supply the polarisation voltage for the condenser microphone if required E A sound intensity probe with remote control for sound intensity and sound power measurements Accessories Windshield to protect the microphone or an all weather windshield or an outdoors microphone unit Extension cable for connection to the acquisition unit Tripod Measurement case Type 1 or Type 2 acoustical calibrator to perform calibrated measurements Measuring instrument Notebook industrial or desktop computer that meets the minimum requirements specified by 01dB Metravib with a Windows 2000 or Windows XP operating system Acquisition unit connected to the Notebook e g SYMPHONIE box dBFA suite acquisition and processing software with optional modules The photograph illustrates a field vibration measurement on a rotating shaft in an industrial area with a 01dB Metravib measurement chain All these elements can be purchased from 01dB Metravib Contact your sales representative for more information
33. PSD RMS and PWR Refer to paragraph 11 4 for a complete list of spectral units available in dBFA PAGE 154 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 3 5 Harmonic cursors Use the command mi Display Cursors to display the harmonic cursors on the graphical view of a narrow band spectra The following dialogue box appears on screen Define the maximum count of harmonic cursors that you would PO like to see on the graph Y Harmonic cursors si Maximum count 2 Cancel The main measurement window then looks as follows im dBFA32 REL Oe 0 000 0 002 0004 0 006 0008 0 010 Linear 200 200 Trigger Internal The display of the levels corresponding to the different markers appears on the right hand side of the spectrum PAGE 155 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 3 6 Integration Derivation of spectra to be displayed Jie ae l i ee Use the command fa Display Integration Derivation to carry out a simple or double integration derivation of an active narrow band spectrum in the main window of the real time mode The following dialogue box appears on the screen There are two cases Acceleration Cancel Derivation Integration of an autospectrum According to the physical unit of the measured spectra the spectra is displayed integrated or derived Derivation Integration of a transfer function The user may visualise the chosen transfer function by inte
34. Plot after selection of one or several data items in the list to display the data in a graphical manner when possible The data are displayed either in different windows or in the same window stacked or superimposed depending on the elements selected Double click on a data item in the list to also display a graphical view Data items of the following types may be displayed graphically in dBFA Signal editing view Signal recording signal or tacho Leq levels and sound pressure levels Fast Slow Impulse versus time Psychoacoustic criteria versus time Impulse response Speed profile tachometry Broad band spectrum and or multispectrum view Octave third octave 1 Nth octave band spectra Bark band spectra Active reactive and free field intensity spectra m Histograms and cumulated histograms Echograms Narrow band spectrum and or multispectrum view Narrow band autospectra and cross spectra Transfer functions Coherence Active reactive and free field intensity spectra Sonagram view Multispectra Lissajous view Between two Signal items Nichols Nyquist view Transfer functions and cross spectra Let us now describe each view in the following paragraphs When several graphic windows are displayed a synchronisation of the cursors on all open views is possible provided dates are identical For instance if a signal is displayed along with a multispectrum and if the cursor Is displaced
35. The analysis will be carried out again when this key is pressed again 12 Logo Computation progress this part of the dialog box shows the current progress in the computation for the operator displayed in the status bar According to the type of operator this zone may take different aspects Proportional bar it notifies the user of the computation progress with a scale ranging from 0 to 100 figure on the left hand side Symbol bar it shows the computation progress of the current task for operators made of several operations figure on the right hand side Because of the complexity of some calculations such as computation of psychoacoustic criteria the server cannot know in advance how much time is required to complete the calculation The task currently being processed and an overall progress bar are therefore shown on screen Driver Bruit_blanc CMG q 0 x Driver Bruit _blanc CMG Ioj xj Signal analysis Signal analysis Fe_0 from Eruit_blanc CMG 0 A PSYCHO_0 from Bruit_blanc CMG 20 Task 2 10 PAGE 63 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 3 Overview and configuration of analysis scripts Click on the icon to access to the script configuration dialog box shown below This dialog box is used to select and configure each single operator of the script 1 2 3 4 Script setup Signal analysis Designation Available analysis Active pracessings C weighting
36. USER MANUAL gb_dBFA NUT 043 A 3 7 3 Principle and configuration of the Copy command The copy command may be configured to work in different ways in dBFA Use the command Preferences Copy options to define how the copy command will work The following dialog box appears on screen By default for all graphical views the command Edit Copy can be used to copy the image of the graphical view The data values cannot be copied Copy When copy into the clipboard can be performed as data values are az an image do you wish to Copy of tables of results In some cases for a table of results mainly it is possible to copy either an image of the table or the data values of the table at the ASCCI format Copy the values only Copy the image onl ee oe The default option Be prompted for the type of copy each time allows the user to display a dialog box for choosing to copy either the image or the values of the table of results When a study zone iz defined for an item to copy do Hou wish to The option Copy the values only can be used to copy directly the data values The option Copy the image only can be used to directly copy the image of the table mage C Values Cancel Copy the whole Copy only the study zone it Be prompted for the type of copy each time For the copy and exportation of data items at the ASCII format do pon wish that the time axis to be Copy of an item when a study zone h
37. an order extraction from a Signal item and a Tacho item resulting from the recording of a tachometric transducer on a dynamic channel This operation yields gt A multispectrum versus speed or time containing phase information gt An overall level per extracted order versus speed or time gt An item containing information on the phase per extracted order In the Configuration tab the following analysis parameters may be defined OAF_O Extraction order Phase X E f Management of the trigger input channel Operator Configuration Processing of tigger channel Detection threshold Define the threshold value for impulse detection Add Edit Delete Hold Off delay M onitoring parameters rpm Averaging Step f Miri 1000 Max Jeno Slope definition e Positive Negative Strategy Increasing Block Middle hi Analysis Bandwidth 2000 Hz 601 s Detection threshold Lower threshold Hysteresis Define the lower threshold that the signal must pass to reactivate the trigger for impulse detection case of a poor quality tachometric signal RPM Number of impulse revolution Indicate the number of impulse per revolution Options Hold Off delay Definition of a time period during which the trigger is deactivated as a percent of the time between the two previous triggerings case of a poor quality tachometric Signal W Phase extraction
38. analysis can be applied to a couple of input quantities in order to calculate a cross spectrum The Fourier transform of a signal called x t respectively y t results in a complex autospectrum Gxx respectively Gyy given by Gxx f ue A dt We often represent autospectra as a modulus only We therefore call autospectrum the modulus of an autospectrum complex quantity with a modulus and a phase Let us designate the real and imaginary parts of Gxx by Gxxr and Gxxi respectively Then Gxx 2 Gxxr Gxxr Gxxi Gxxi The result expressed in dB is equal to 20 log10 Gxx REF With REFX 2e for sound pressure levels If the selected physical unit is not the IS unit and if a conversion factor Cx Is calculated e g Cx 9 81 for an acceleration level expressed in g then the above expression becomes 20 log10 Gxx Cx J REF The cross spectrum between channel x and channel y can be computed from the autospectra Gxx and Gyy using the formula Gxy Gxx Gyy Where Gyy is the conjugated complex of Gyy same real parts opposed imaginary parts The modulus of the result expressed in dB is given by 20 log10 Gxy REFX REFY It the selected physical unit is not the IS unit and if a conversion factor Cx is calculated e g Cx 9 81 for an acceleration level expressed in g then the expression above becomes 20 log10 Gxy Cx Cy REFX REFY The phase of the result expressed in radian is equa
39. are still computed There are not computed no value if the box is not ticked The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Arithmetic Z gt S OO Default name MOY_O At least 2 signals autospectra Leq Leq Peak Slow Fast etc Complex spectra cross spectra transfer functions coherence If signals same physical units sampling frequency and references Restrictions If Leq same physical units time basis references type of data If spectra same physical units references band width or resolution narrow bands time basis type of data 3 Signals autospectrum Leq Leq Peak Slow Fast etc sch arn ecu Complex spectra cross spectra transfer functions coherence Loudness levels cannot be averaged PAGE 106 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 6 Time history of an overall quantity There are two ways to estimate the time history of an overall quantity From a time signal This operator allows the user to compute from a Signal item the Short Leg time history of time basis ranging from 5 milliseconds to 999 seconds The overall level may be frequency weighted A Lin B and C and or time weighted according to Leq Classical short Leq time history Peak Time history of the maximum values of the signal over the item duration Fast Fast integration of the elementary short Leq
40. as data items whatever the family of duration less than Data items of the Signal family and of duration ranging from 30 seconds to 1 minute will be displayed 1 minute 3 6 2 2 Definition principle Follow the instructions below to add a new request 2 4 7 3 1 Ve of a request es ame Signal Channel 2 30s toh min 6 Conditions bd mts Logio MEG Fields je vaeg 41 Family Signal AND Tet measurement channel no 2 5 AND Duration OhO1 m00s000 AND Duration gt OhOOrn30s000 m Cancel 1 Give a name to the current request This name will appear in the list of requests in the management dialog box 2 m the first line of the conditions list click on the Fields column and select the desired quantity in the scrolling ist 3 On the same line click on the Op column and select the equality value in the scrolling list 4 Onthe same line click on the Value column and select a value in a scrolling list or input it manually 5 Repeat steps 2 to 4 for each condition to define 6 Select the Boolean operators in the Logic column to define interactions in between the conditions 7 Define the order of the request conditions remove a condition if necessary 8 Validate the request PAGE 51 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 6 2 3 List of the values available to define a request Here is a complete table of the different choices available when defining a request Fields Descriptio
41. by operator can be displayed in the same window lol x 1000 1200 i 1600 1800 2000 repr Hz d8 1e 006 m s RMS Comment Status Decision 7 PAGE 164 DBFA SUITE USER MANUAL 9 1 3 1 Display set up Use Channel l x to select the channel to display 3 Dynamic dB Lin Min Er dE Max 1150 dE Frequencies Min lo Hz Max 1250 Hz It is also possible to display a meter showing the real time speed using the button Lal and to display the signal using ee 54755005 EN 9 1 4 Description of a post processing order extraction Dynamic set view 0 Frequency set view Monitoring channel m id gb_dBFA NUT 043 A Use LZ or Plot Parameters to define the display dynamic range 0 Open one or several measurement sessions and select Signal Speed profile elements for analysis Open the post processing order extraction window using Analysis New analysis set up PAGE 165 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Retrieve selected Signal and Speed profile elements from the active session use the batch window to view elements to analyse group Signal and Speed Profile elements two by two 1 Signal 1 Profile or three by three 2 Signals 1 profile two channel recording import other Signal elements from an open session deactivate analysis for one of the elements O set processing parameters F5 Analysis and storage paramete
42. compute the overall level over the item duration It varies from 1 ms to 999s Frequency weighting Select the weighting to apply to the computed overall level A B C and Lin Time weighting Select which time weighted overall level has to be computed Leq Peak Slow Slow Max Slow Min Fast Fast Max Fast Min Impulse Impulse Max If for example a time step of 1 s is chosen for a 2 s long audio recording only two values will be calculated one value per second The result will therefore be useless It is recommended to specify as small a step as possible without increasing calculation time too much Excessive calculation time may cause problems if the computer has insufficient power This should also be remembered with respect to the number of quantities and weightings involved in the calculation The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name LEQ 0 Activefor Signal Impulse Response Apply to one item onl Family of the result PAGE 108 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 6 2 Overall level time history GLOBAL This analysis results in the time history of the overall level of a multispectrum with frequency weighting The following dialog box appears on screen In the Configuration tab the following analysis parameters may GLOBAL_0 Overall level time hist
43. dB the dynamic is displayed in decibels according to the IS reference and depends on the transducer type of each channel Lin the dynamic is displayed in physical units according to the transducer type The command Actions Autoscale F9 allows the user to adjust the display dynamic of all existing curves according to the measured levels Autoscale adjusts automatically the scales of the Y axis of all curves in order to enable a correct visualisation of all curves 8 3 3 Overall levels Use the command Display Overall levels to display up to two overall levels on the right hand side of the active display in the measurement window The following dialogue box appears on screen Overall levels we Lin e Weighted The display of overall levels is only possible for autospectra and authorises the display of The overall Lin level unweighted An additional weighted overall level A B C etc Weighted spectra The option weighted spectra activates spectrum display using the selected frequency weighting The spectra will be weighted in this case Refer to paragraph 11 3 for a complete list of frequency weightings available in dBFA 8 3 4 Spectral units Spectral units RMS Cancel RMS Use the command Display Spectral unit to modify the spectral unit of the spectrum of the active window The dialogue box shown opposite appears on screen You can choose amongst the following spectral units ASD
44. description 01dB Metravib has developed a modular PC based measurement chain similar to that used by traditional stand alone measurement systems This generic approach also applies to sound level meters tape recorders or multi channel analysers First the transducer transforms a physical phenomenon into an electrical input signal Secondly the signal conditioning block transforms and or amplifies the input signal for treatment in an acquisition unit Conditioners require power supply Control of the instrument and output of the results is required Control is via key commands on a control panel Results such as a spectrum or time history graphs may also be stored for example as raw audio data similar to a DAT recording or as a spectrum memory or set of Ln measurements Results are then available at the convenience of the user for post processing operations such as building acoustics calculations Finally the instrument may have an interface to a computer for further analysis and reporting The personal computer may be used as a host to a stand alone instrument Duplication of function however quickly becomes apparent A PC may handle many internal functions of the dedicated instrument more efficiently Benefits of the PC include access to greater storage capacity input output devices higher resolution with a Windows style graphical interface and general integration with the computer based design environment The computer may also take
45. displayed either in polar form modulus and phase or complex form real and imaginary parts An internal signal generator can be used as an option to generate a white noise a pink noise a sinus or a loop signal through an amplified loudspeaker Signal recording can also be performed in the real time acquisition mode Use the command Acquisition New measurement set up to start a new measurement The dialogue box shown opposite appears on screen The dialogue box shown opposite appears on screen after creation a new real time measurement mode The user can define the main acquisition parameters before starting the measurement itself Configuration Moss RUNcUn TE Following steps may be done Parameters Average Generator Curves a Activate calculation of cross functions between active channels if possible Define the acquisition parameters frequency range resolution quantities to store etc Define the averaging parameters type of averaging averaging duration Activate or disable the internal noise generator white pink sinus loop option Define the curves to be displayed in the measurement window Run the measurement The real time measurement window appears on screen Save the measurement configuration All the parameters of the measurements are saved in a configuration file with the extension INT for this real time acquisition mode Run Save Cancel The us
46. even order from 2 to 30 The following dialog box appears on screen HIGH_0 High pass filtering In the Configuration tab the following analysis parameters may be defined Operator Configuration Notification Low cut off frequency Hz 07 1 1 Low cut off frequency define the cut off frequency in Hz Filter order 20 ka Filter order select the Butterworth filter order between the following values 2 4 6 8 10 12 14 16 18 20 22 24 26 28 and 30 Slope dB per octawe 120 The filter order defines the octave fall off rate dB octave and therefore the effectiveness of the filter The greater the filter order the greater the attenuation of low frequency bands je Save the result Annuler Low pass filters remove components with a frequency lower than the specified cut off frequency with an octave fall off rate dB octave that depends on the filter order The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name HIGH_O Activefor Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families PAGE 81 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 3 Band pass Operator PASS This analysis results in a band pass filtered time signal Butterworth even order from 2 to 30 The following dialog bo
47. fmin minimal spectrum frequency Hz resolf frequency resolution Hz unite unit string Note ID is expressed in physical units and in energy Result Figure No 1 OE Xx File Edit Window Help Example fb m file on CD ROM function fb ID nom periode fmin resolf unite figure nb size ID t 1 1 nb 2 f 1 1 nb 1 vect_t t 1 periode vect_f fmin f 1 resolf surf vect_t vect_f max 10 log10 1D 2e 5 2e 5 0 shading interp rotate3d xlabel Time s ylabel Frequency Hz aff sprintf dB s unite zlabel aff 4 view 0 90 a Time s title nom dBID17 4 6 11 7 Type COMPLEX NARROW BAND SPECTRUM Syntax function xxx ID nom fe unite ID identifier of the variable dBID n ID dBFA nom name of the variable ID comment string periode period time step fmin minimal spectrum frequency Hz resolf frequency resolution Hz unite unit string Note ID is expressed in physical units and in amplitude complex spectrum Example with averaged spectrum period 0 Result fbc m file on CD ROM Figure No 1 Pill E File Edit Window Help dBID42 function fbc ID nom periode fmin resolf unite 150 figure nb size ID T f 1 1 nb 1 E vect_f fmin f 1 resolf i subplot 2 1 1 0 ES plot vect_f max 20 log10 abs ID 2e 5 2e 5 0 eae E en xlabel Frequency Hz aff sprintf dB s unite ylabel aff title nom subplot 2 1 2 plo
48. for audio data analysis If the user wishes to keep this script with the current settings he or she can duplicate the script and define different analysis types and analysis parameters The default and user defined scripts are automatically saved for any subsequent analysis 6 Cancellation click on this key to delete a user defined script obtained after duplication from the calculation server Default scripts cannot be deleted 7 Access all scripts click on this key to display and access all the analysis scripts contained in the calculation server and not only the scripts compatible with the data items selected in the measurement session In this mode no analysis can be performed Click again on the same key to unlock the calculation server and perform an analysis This mode is also used to assign operator scripts to shortcut buttons in the session toolbar See the section on shortcuts for operator scripts 8 Click on this key to launch the analysis process according to the selected script and for the selected data items 9 Abort the script currently being executed is stopped The analysis is thereby aborted No result is saved in the measurement session datafile PAGE 62 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 Interrupt click on this key to interrupt the analysis process The partial results are saved into the active measurement session datafile 11 Pause click on this key to temporarily stop the analysis process
49. for the other unit displacement PAGE 95 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 3 2 Frequency recomposition Operator RECOMPF This analysis results in the recomposition of a broad band or narrow band multispectrum into a multispectrum of different frequency bandwidth The following dialog box appears on screen RECOMPF_0 Frequency recomposition Operator Configuration Notification Required bandwidth Field i Free Diffuse Save the result Annuler In the Configuration tab the following analysis parameters may be defined E Required bandwidth Select the octave sub division of the spectrum to recompose For a frequency recomposition in Barks bands with conversion to a Loudness level give details on the type of sound field Free field or Diffuse field If the box Ignore erroneous values is ticked frequency bands that present erroneous values are still computed There are not computed no value if the box is not ticked The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name RECOMPF_0 Activefor Autospectrum Intensity active free field reactive Apply for one item only Narrow bands to Bark bands a minimum of 5 narrow band Restrictions values is required to synthesis a specific Loudness Broad band to broad band the required bandwidth must be greater than
50. from 1 ms to 999 seconds Save the result Annuler Field Select the type of sound field free or diffuse to compute the specific Loudness level Note that this type of analysis is required in order to perform an analysis with the operator Overall Loudness level time history The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name BARK_0 Activefor Signal impulse response Apply only for one item Family of the result Bark spectrum PAGE 114 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 7 5 Time history of psychoacoustic criteria PSYEV This analysis results in the time history of psychoacoustic quantities Loudness Zwicker B Sharpness The following dialog box appears on screen PSTE _O Evolution of psychoacoustic criteria Operator Configuration Notification Calculated quantity Bark bands for computation Miri 20 100 Hz Max 24 12000 15500 Hz Time step Select the integration time to calculate the time history This time step may vary from 1 ms to 999 seconds Field In the Configuration tab the following analysis parameters may be defined Calculated quantity Select the psychoacoustic criterion for which the time history will be calculated Loudness Sharpness Bark bands for computation Gives the minimum and
51. horizontally data of X axis and Y axis are displayed in lines PAGE 57 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 7 4 Exporting data in 01dB Metravib WAV format or in MP3 format Select a Signal item in a measurement session and go to File Export to export data in 01dB Metravib WAV format Microsoft WAV format including additional information on the measurement or in MPEG layer ITI MP3 format To export a set of signal recordings use the operators Export in WAV format section 14 6 8 2 and Export in MP3 format Section 14 6 8 3 3 7 5 Exporting data in ASCIT format TXT text file The File Export command is used to copy data from one or several items in a measurement session into a text file txt in ASCII format These files can be opened with many applications Windows NotePad word processor spreadsheet application database Any operation can then be performed to edit a measurement report or do calculations on the data Each field in the ASCII file is separated from the other by a tab character making it easier to import these files into a spreadsheet processor 3 7 6 Exporting data in UFF format Universal File Format Select one or several items in a measurement session go to File Export and select the Universal File UFF file type to export data in UFF format This file format is universal and recognised by many measurement systems 3 7 7 Exporting data in Lexade format Exploita
52. is modular in structure some of the functions described in this manual may not be available in your copy of the software To upgrade your version with optional modules contact your 01dB Metravib agent TABLE OF CONTENTS PAGE 5 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 4 MAS TINGS ORDA TAIT EMSA ABE BS tado Aid 46 3 4 1 1 Data paraineters for he lable Or results x2255 A he eed i ee ace ee hcl as 47 3 35 DESCRIPTION AND SELECTION OF COLUMNS IN A MEASUREMENT SESSION WINDOW cccceecceeseesseeseeess 48 3 6 EDITING AND RUNNING REQUESTS DATA SORTING csssssssecccecceseseecccceesassseeeccceeesaeseseeceeeesuaaeeeeceeeeaaaees 49 361 OVERVIEW Of TEGUESIS editing siivssidcse odessa ir e E E E T bain E E E 49 362 Addormodijvareguesi localorelobal orea li 50 DON OVON IOW iani oea EA as 50 3 6 2 2 B Tsp Na RUA it 51 3 6 2 3 Last of the Values available to definea TE eor atch ides Ache dees iecd e 52 SOS RUMME ACUESTA T EAE T EO T OE TETN 54 3 7 RESULT EXPLOITATION AND CUSTOMISATION iaa 55 A A TOA E T TEAT EES TATE 33 3 7 2 Exporting data to a word processing or spreadsheet software ooooninnncinuoucocooonananananan aaa 56 3 7 3 Principle and configuration of the COPY COMMANdA oooooooocnnnnnnnnnnnnnnnnnnnnnnnnnononnnnnnnnnnnnnonnnnnnnnnnnnnnnnnnnnnnnoss 57 3 7 4 Exporting data in 01dB Metravib WAV format or in MP3 format 58 3 7 5 Exporting data in ASCH format TXT text file ocn adan 58 3 7 6 Exporting data in
53. it was last saved the version and the number of items contained in the CMG file E By ticking the details box the size in bytes of the datafile the start and end dates of the measurements the number of events signal recordings spectra etc as well as general parameters dynamic range number of codes etc Once a file has been selected click on the Open button to open the datafile and proceed with its analysis 3 1 3 Close a CMG datafile To close a measurement session file of CMG type use the command File Close Closing down the window of the datafile will also result in closing the CMG datafile All others windows results listings plots etc will be closed as well dBFA will also prompt the user to save this CMG datafile if any modifications have been made to it before closing 3 1 4 Save a CMG datafile Use the command File Save CTRL S or File Save As to save the measurement session on the computer hard disk 3 1 5 Delete one or several CMG datafile s Use the command File Delete session s to delete one or several measurement session datafiles including temporary files A dialog box is displayed on screen in order to select the datafiles to delete PAGE 21 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 2 Measurement session window overview Toolbar of the measurement session window g dBFA32 Cmg Exemple CMG Main window File Edit Acquisition General Campaign Preferences Window lej
54. items channels is necessary Item which isn t displayable can be used for post processing LEQ spectra etc PAGE 180 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 3 Frequency weightings First here is the list of all the frequency weightings available to calculate overall levels A weighting Sensitivity of the human ear at low levels Lin weighting No weighting linear B weighting Sensitivity of the human ear at medium levels C weighting Sensitivity of the human ear at high levels G weighting Infrasound weighting Pink Lin weighting Global Lin with respect to pink noise E Road Lin weighting Global Lin with respect to road traffic noise Pink A weighting Global A with respect to pink noise road A weighting Global A with respect to road traffic noise PL weighting Correspond to a Loudness acquisition channel displayed in dB equivalent PN weighting Correspond to a Perceived noise level PNL acquisition channel displayed in dB equivalent TPN weighting Correspond to a Perceived noise level Tone corrected PNLT acquisition channel displayed in dB equivalent The following vibration frequency weightings can be selected 1902631 part 1 Principal weightings Wd horizontal vibrations and Wk vertical vibrations to evaluate the adverse effects of vibrations on human beings relative to health comfort and perception issues Additional weighting Wc seat back vibration measurement We rotatio
55. make it active and move the harmonic cursors using the CTRL and arrow keys so that they correspond visually to the harmonics If a significant harmonic is found it will be labelled with a sign if it is exactly on the FFT line or with a sign otherwise OK l click on ox to launch the interpolation calculation and obtain calculated values that are closer to the physical phenomenon If the ox button is disabled it means that no line corresponds to the emergence and tolerance criteria It is then necessary to better adjust the search parameters It is also possible to impose a significant harmonic by double clicking on the cursor of the corresponding harmonic In this case an X will be displayed next to the harmonic Sideband cursor For sideband cursors the principle and the stages are the same but a second cursor needs to be activated see Section 13 3 3 1 Place a cursor on the fundamental frequency and then the second cursor on the next greater side band right of the fundamental frequency 210 x E aes EN A Itt th o ii j 133 Deltal 12 50 Deta Y ID 32 0 8 ID 32 Average G1 Frequency modulation EAEE 510 00 69 3 120 110 am O fe rade fe ele ef A ee et Pete ee Tee eee i E Fe aa A frf e ox ttl t E DeltaX 12 50 Delta Y ID 32 0 8 1D 32 Average G1 Frequency modulation E NO a gt ji Ys ca Yor Set ve ee ee eee naa
56. need to consider which processes are better handled by stand alone hardware and what can be transferred to the PC environment The use of personal computers for acoustical measurement and data processing has been a topic of much discussion even controversy over recent years The phenomenal growth in PC technology now offers the benefits of computational speed and flexibility that are being employed in many areas of research and engineering applications Traditionally the function of acoustical measurement has belonged to the stand alone instrument while the computer has carried out the tasks of data storage display and basic processing The interface between the two has been either an RS 232 serial communication or manual entry via a keyboard Human error excessive time and long rolls of silver paper are just some of the disadvantages of this system An attractive solution for the pure technologist is to build a PC based instrument though the benefits over the stand alone instrument should be apparent Alternatively the design of an optimum PC based measurement system will depend on the management of data handling between the dedicated hardware and the PC environment The possibility of flexible and creative solutions that offer a very high degree of accuracy over a wide range of applications have been sought and developed over the last fifteen years by the team at 01dB Metravib PAGE 9 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 1 2 General
57. new request or edit the current request x _ gt Mame Signal Channel 2 30s to 1 minj Conditions DESEO a ETS Signal AND 2t measurement channel no 2 0h01 m 0s000 Oh00m 30000 Duration Duration gt Cancel Ql Stage 2 Request editing Give a name to the current request Ql Stage 3 Define the logical conditions of the request Define all the required conditions of the request Start by the Fields field select a given type of information then its value If more than condition is defined select the Boolean operator AND OR that will define the interactions in between the request conditions Q Stage 4 Management of the request conditions Define the order of the conditions remove a condition add a condition etc L Stage 5 Run the request Use the command Datafile Current request or select the request in the scrolling list of the measurement session toolbar to execute it In the above example after execution of this request the following data items only will be listed in the measurement session window audio events acquired on channel 2 of duration ranging from 30 seconds to 1 minute Signals will then be sorted according to their duration by clicking on the title of the field called Duration in the measurement campaign PAGE 15 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 3 2 Off line processing analyses Use the corresponding icon or the command General Calculation server to initiate
58. of personal computers in acoustics and vibrations both for measurement and results processing The advances in PCs have been nothing short of phenomenal driven by the fast moving requirements of information technology in the office environment and these benefits are starting to filter into our world of acoustics in the form of more flexible measurement tools The pure technologists amongst us would doubtless plunge headlong into building an instrument on a PC which in principle is not a difficult job but the resulting system must offer clear benefits to the user before it can be accepted as a true alternative to more dedicated instrumentation This is where one of the traditional divides has emerged between instruments and PCs The stand alone instrument has always been used to provide the measurements and the computer has been used simply as a storage device for archiving and displaying results with simple post processing functions The interface between the two has either been in the form of a simple RS 232 serial communication or via manual entry of results from a paper printout This latter in particular has been responsible for many errors with the tedium of copying numbers into a spreadsheet for example from a long roll of silver paper It is only relatively recently that computers have moved into the measurement arena supported by the massive increase in available processing power However to build a sensible instrument using a PC we
59. on the signal view then it will do the same on the multispectrum view Use the Session Time Le synchronisation menu or the button in the toolbar to activate this function PAGE 26 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 1 Signal view In this type of graphical view any time history of a signal in physical units noise and vibration quantity level in dB or in physical units can be displayed An example of signal view is given below Select the channel units to display zoom functions etc Define the Signal plot Cmg Exemple CMG olx study zone and cht fes 510121 BY Deta 152 090 ms the threshold Envelop ID 159 Ch 2 Pa s X Y1 search Display the item over its complete duration functions YU Pu aNd EN A ASS ee ree wry ADAN a Zoom an given part of R EN TO T ETER 0 the signal Several Signal items can be displayed in the same signal editing window if there were multiple selections in the measurement session It is then possible to link the cursor displacement on all views by holding down the CTRL key while moving one cursor or by pressing the key ch 1 caed PE chanmneifor teven Cursor synchronisation when several signals are displayed Select the display unit Beginning of the study zone End of the study zone Activate Deactivate automatic autoscale for the Zoom Pa bl 4 Perform an autoscale in the signal zoom view WH Define the study zone in between the cursors Aane t
60. operations ay Definition Editing of data parameters for the K Definition Editing of display parameters for the graphical view graphical view Curve lavout Fah Go to stacked superimposed mode if several curves Y with the same characteristics are displayed Activation Deactivation of Lin overall level display pre Activation Deactivation of second cursor adh BENE curs Cursor synchronisation if several curves are Itt Display harmonic cursors autospectrum only displayed Launch interpolation calculation on harmonic and OK tlt Display sideband cursors autospectrum only sideband cursor table tlt Display maximum x values autospectrum only Display maximum autospectrum only 123 Display identification labels for multiple cursors autospectrum only The levels are calculated from international system units IS It is possible to modify the default values using the command Preferences Units management See paragraph 11 1 It is possible to display in a same window as many stacked curves as the system can handle regardless of their characteristics As long as the elements have the same units Pa m s curves can be superimposed PAGE 32 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 3 1 Display parameters of the graphical view Set up the graphical display parameters with the command 1 Plot Plot set up The plot is updated immediately when a modification is made Each plot has its
61. parameters have been defined click on OK The section is then displayed in the list and the graphical display of the weighting window is updated Use the Hole window to cut a section of a signal Use the Zeros window to remove spikes from the signal Delay button Click on this key to define a delay in milliseconds before and after the weighting window The following dialog box appears on screen Predelay 200 us Post delay 50 me Set these parameters to zero if no delay is required Name of user s window Ea Mame demo Save button Once the window has been defined click on this key to save it for later use A dialog box is shown on screen in order to give a specific name to that window The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name Signal Impulse Response families Applies for one item onl Family of the result Signal Impulse Response families PAGE 87 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 12 Re sampling operator SAMPL Operator Configuration Notification This processing re samples the signal to a frequency specified by the user Required sampling frequency Hz 2000 The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator IM Save the resu Annuler Activefor_
62. positive button it is used to start and validate a measurement result The lower button grey is a negative button it is used to prematurely stop an acquisition or to repeat the current measurement The left LED green and the right LED red are used to indicate the different states of the sound intensimeter waiting for measurement start acquisition ended overload Red LED Green LED Blue button Grey button To configure this remote control perform the following operations Choice and configuration of the remote control object Assignments of input and output contacts Connection and operating process PAGE 176 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 4 1 1 Choice and configuration of the remote control object Hardware configuration A parao vil x 3 z t t t gt Available remote controls At the hardware configuration stage select the remote Ae E control tab shown only if the DBCD32 INI file is present in G A A S automatic calibration the 01dB Metravib programs directory ASS Hardware peripheral Remote cc New Ope Name D A AGB43 hcf Click on the gt gt key and select the remote control G R A S sound intensity probe and click on OK Remote control selection After the selection of the remote control click on the Configuration key and select the communication port Symphonie The physical remote control built in the probe handle will be connected to th
63. responsibility for system control Note that some existing analysers actually feature an internal x86 PC processor as the system controller As graphics user interface storage and post processing are all handled by the PC platform and the type of measurement performed is defined simply by the application software running on the computer which sends calls to the hardware resources as necessary The Level of Accuracy achieved by a Sound Level Meter is determined by its grade and is regulated by the legal requirements of the Standards IEC651 IEC804 IEC1043 and their national equivalents Minimum requirements are given in respect of dynamic range linearity frequency response and indications What is a PC based measuring system It is a system comprising hardware resources software modules and a host computer which must meet the current Standard specifications for its class The requirements currently reflect the use of dedicated instruments but until they are revised the new instruments must still comply 01dB Metravib is dedicated to the design and development of portable PC based measurement systems that offer a very high degree of accuracy and are intuitive to use in all aspects Our systems are type 1 approved in several countries This accuracy rating applies to the use of generic computing hardware that in practice enables any brand of computer to be used that meets current minimum standards PAGE 10 DBFA SUITE USER MANUAL gb_dBFA
64. script Arithmetic___________________ Default name E Activefor At least 2 signals autospectra Leq Leq Peak Slow Fast etc If signals same physical units sampling frequency and references Restrictions If Leq same physical units time basis references type of data If autospectra same physical units references band width or resolution narrow bands time basis type of data Family of the result Signal autospectrum Leq Leq Peak Slow Fast etc eo Loudness levels cannot be subtracted PAGE 105 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 5 3 Averaging Operator MOY This processing averages all the selected quantities The user may choose either to perform an algebraic or logarithmic average The following dialog box appears on screen MOY_0 Averaging Operator Configuration Notification In the Configuration tab the following analysis parameters may be defined Arithmetic Algebraic rule Amplitude 40 dB 40 de 80 dE Algebraic rule Energy 40 dB 40 de 80 de igarithmic rule Select the algebraic rule for an algebraic average of data items Amplitude 40 dB 40 dB 46 dB Energy 40 dB 40 dE 43 dB Logarithmic rule Select the logarithmic rule for an energetic average of data items T Ignore erroneous values I Save the result Annuler If the box Ignore erroneous values is ticked frequency bands that present erroneous values
65. the it analysis Orders may be non integers Delete Tracking parameters rpm Tracking parameters Define the speed interval between stefo we Mex e000 two FFT spectra calculation Enter the minimum and the maximum speed for the analysis Strategy Increasing Strategy Indicate whether it is a run up Increasing or a ee Midde y run down Decreasing Recomposition method Di constant Block Synchro Indicate if the speed used to date the Dn constant 0 3 spectrum is that at the beginning at the middle or at the end of the analysis time block il Save the result Annuler Recomposition method Define which frequency band will be used for the energy calculation of orders Df constant the frequency band used to calculate the order will be a band with a constant width of Df Dn constant the frequency band used to calculate the order energy will be a frequency band proportional to the speed increasing with the frequency Df Dn x Speed 60 with Speed in rpm The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name Activefor Signal Speed Profile families Items must belong to the same measurement Result family Overall RPM Autospectrum PAGE 129 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 12 2 Order Phase Extraction OAF_0 This operator performs
66. the acquired quantity for a real time measurement Type of averaging method used to Average type compute the data item Max Min Average Stat ist meas Number of the measurement Channel no channel used to create the item E For cross spectra the number of gt 1 2 3 4 Channel a each channel used to calculate the cross spectrum is described Period Base duration or integration time of Manual input 0 00000 seconds data items that vary with time ee 125 ms 0 12500 Frequency weighting applied to the A B C D G Lin PL Pla PN Pink A Pink Lin Road A data item during acquisition or off Road Lin TPN Wb WBc Wc Wd We WE Wh Wj line analysis A B C Lin weightings y NS PO E He A Ba vibration weightings etc Value column Wk Building acoustics spectrum Spectrum for the calculation of building acoustics criteria eee i Manual input 0 00000 Statistical index Ln O L99 8 99 8000 X axis unit for a quantity acquired with other software not 01dB Manual input X axis unit for a quantity acquired with other software not 01dB For example the temperature Background noise emitted noise received noise Yi axis unit For cross spectra Y1 corresponds to Manual input the physical unit of the first item and Y2 corresponds to the physical unit Y2 axis unit of the second item used to calculate the cross spectrum Manual input 0 00000 Legend Less than Less than or equal to Not equ
67. the calculation server that allows the user to configure and execute an analysis script The following sketch illustrates the off line analysis process 10 x Signal analysis ng gt No oppration in progress 4 91 dB Stell TA i rma ml mi 7 Script setup 3 Designation Signal analysis l I 4 Available analysis Active processings Broad band spectrum FE 0 Narrow band spectrum Undersarnpling Low pass filtering oo High pass filtering Remove Band pass filtering cuttband filtering x Comments Broad band pectrum Cancel 6 FC_0 Broad band spectrum e x Operator Setup Frequencies Bandwidth Min Hz Wlas Hz 5 1 3 octave 0 hal 20k Full octaves PAGE 16 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Q Stage 1 Select an analysis script script management Select with the mouse in the measurement session window all the data items to example audio records Then select in the list of the calculation server dialog box a pre defined analysis script e g audio analysis or a user defined script that can be created with the corresponding icons UU Stage 2 Edition of the analysis script Click with the mouse on the corresponding icon to display the script configuration dialog box L Stage 3 Select the required processing functions Select in the list of available processing functions the different types of analyses required and then
68. then be used to perform a process into the a E us Fa P z emo o go process on each item successively batch list Group by 1 hd PAGE 135 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Complete procedure Select items to process in the measurement session EX or Main Menu Operation server to open the server and display the window below ails ee la xl The server displays the scripts that can be applied to the set of A selected items No set up is required here for the time being since we will perform a processing on each item successively A batch processing will then be used No operation in progress E 1dB Stell Batch DBFA32 gt To do Z or Session Menu Batches to launch the batch 1 ej Eta processing window shown opposite jee e Oran Se Diemo CMG SUCCESS Diemo CMG Ciemo CMG SUCCESS Demo CMG SUCCESS Cemo CMk Ciemo CMG Group b fi Sort the items for analysis ey Reset the batch The status of all signal items switches to To process Import selected items to the measurement session LA ee Failure Toda Todo The following function are available Deactivate processing for selected item status becomes inactive Delete selected item from the batch Delete all items from the batch Group by gt Grouping items is useful when performing a batch analysis with a script calculating a cross spectrum i e
69. tias 103 LOI ARIANE CIO Prato A A Si N a 104 4 6 5 1 Addition Operor PLUS acia taa ia aia 104 4 6 5 2 subtraction Operator MOINS cats E AAA 105 4 6 5 3 Averacine Operator MOY a 106 4 6 6 Timehistory Of CI ONE GUN a i td 107 4 6 6 1 Overall level Operator EEO ick ds 108 4 6 6 2 Overall level time Nistor GLOBAL sites od iros 109 4 6 6 3 Overall Loudness history Operator BGLOBAL iia 109 AOF ESVENDACOUS ES A E A oia ae 110 4 6 7 1 Bile INS AA O RRA 111 4 6 7 2 Stationary onto a dio liarla 111 4 6 7 3 Psychoacoustic criteria Operator PSYCHO a e 113 4 6 7 4 Specie Loudness Operator BARR ramena a iio lo eiii 114 4 6 7 5 Time history ot psychoacoustic criteria PSY EV kececeran tees taeslaaindeateneedenlenilla ceectestlantadestens 115 IS ELO IRIS LOM GIS ceed EE O O 116 4 6 8 1 Export to MATLAB format Operator MATLAB oococccccccnccncnnnnnonnnnnnnononnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnininoss 116 4 6 8 2 Export to 01dB Metravib WAV format Operator WAVO1DB ooncnnnnnnninininoninoninininininininininininnnanannnanananann 117 4 6 8 3 Export to MPS Tormaboperator ME 3 haisen aaa 118 109 ODE OS OW ONE LEVELS A a ol 119 4 6 9 1 Elstosram Operator MIST O lt les 119 4 6 9 2 Percentile Opeta or Rx li e nd ll ah Saal 120 4 6 10 ROOM AC OUSIL AA O cases le caida eins II tradi A N seu sadeenige IZI 4610 Echosram Operator ECHO iS 121 4 6 11 MATLAB connection operator MAT CO das 122 4 6 11 1 Use of
70. to drive sound intensity and sound power measurements from the 50AI intensity probe handle in dBFA After the selection of the configure its parameters remote control After the selection of the remote control click on the Configuration key to configure the remote control object parameters The following dialog box appears on screen Define in this dialog box the name of the remote control and the communication interface to use either a Serial port or the SYMPHONIE or HARMONIE digital inputs outputs The duration parameters refer to the states of the input and output contacts of the remote control In the example shown aside and for input contacts the state Long push corresponds to a continuous essential push of 1000 ms minimum the state Double click corresponds to two successive key push of time interval less than 200 ms remote control set up Hame Communication Serial Patt Duration parameters me Blinking Flash Long push Double click Assignments Inputs Outputs generic 2 inputs 2 outputs Remote control name Select the communica tion interface RS232 or SYMPHONIE HARMONIE digital inputs outputs on rom me Define the duration parameters for the input and outputs contacts Define the message associated to the input and output contacts mes For output contacts the state Blinking generates a voltage on a pin of the connector of the communication interfac
71. tre principale ioj xi Tous les mentsD y S l 1 66 5 ID_ Famille Type Grandeur_ P Nom Date Lieu tere voie Dur e _ P riode Moyen Axe Y 61 Le q Fast A Fast 09 12 98 13 37 33 Voie 2 0 01 14 0 060 Pa 62 Autospectre 01 14 0960 Pa 63 Leg File Edit window Help 01 14 0 060 sone GD 64 Leg 01 14 0 060 noy 67 Audio aS dBID163 1 25600 Pa 68 Audio i 1 25600 Pa 69 Audio 1 25600 70 Audio 0 15 1 25600 71 Audio 1 25600 72 Audio 1 25600 73 Audio 0 1 1 25600 83 Interspectre 0 125 87 Autospectre 0 125 88 Fonction de tra 0 05 0 125 1 Pa Pa 91 Fonction de tra a 0 125 Pa Pa 92 Interspectre o 0 125 Pa Pa 94 Fonction de tra 0 125 1 Pay Pa Pilote Cmg Exemple CMG Moyenne Moyenne Communication matlab y l Moyenne Moyenne Biz Moyenne Pas d op ration en cours J5 Moyenne Moyenne 105 Intensit active 0 Moyenne 106 Inconnu Moyenne 107 Inconnu Moyenne 4 Pr t P NM E AD marer A 2 EP y X E 25 HB E amp i mn 2Boite B Explor W Micros gE dFa3 Amar EJrigur BOR 16 37 We consider the argument list passed to the function ID Name of the variable that shows the item selected as script input in dBFA in the MATLAB space This identifier is created as follows dB n where the number is the ID of the item in the dBFA measurement session Nom Descriptive string of the item including the name comments Used here as figure title fe sampling frequen
72. units the type of data the weighting window frequency and time resolution Family of the result Frequency response 1 H1 Restrictions PAGE 102 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 4 5 Frequency response cross function H2 Operator FBH2 This processing produces from the autospectrum Gyy of the output signal and the cross spectrum Gxy between the input and the output the transfer frequency response defined by Gyy Gyx The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Frequency response functions Default name Autospectrum Channel 1 Autospectrum Channel 2 Cross spectrum Channel 1 Channel 2 R ee Check the compatibility of the physical units the type of data estrictions E E Z 3 A the weighting window frequency and time resolution Family of the result Frequency response function H2 4 6 4 6 Inverse frequency response cross function 1 H2 Operator FBIH2 This processing produces from the autospectrum Gyy of the output signal and the cross spectrum Gxy between the input and the output the frequency response function defined by Gyx Gyy The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Frequency response functions Default name Autospectrum Channel 1 Autospectrum Channel 2 Cross spect
73. z calculation to emergence E E band The Emergence criteria parameters are used to set parameters for the detection of maxima Enter the minimum emergence with respect to the level of the two symmetrical neighbouring lines located at X 2 lines on the left and X 2 lines on the right X being the Number of symmetrical neighbouring lines These parameters are defined for all measurement sessions and do not need to be reset They should however be adapted to the different types of spectra encountered Launching harmonic search and calculation of interpolated values Open the plot of the spectrum to analyse and follow the steps described hereafter O Place the cursor on the fundamental frequency O Press In to display harmonic cursors and a table of values corresponding to the FFT lines _JDisplay spectrumharm bandlattMG aa Fist ofthe harmonics ao lt E 2 a olin lod L 17 50 lt Display spectrum harm_bandlatCMG ID 34 ID 34 1 250 Hz i i Harmonic i de ees GATT Oe ak da ead CS Use a to have the table always popped feel enh ila We i ae hee AA cia displayed in the foreground lees aera A A ee A A Vee Ore Ries Sao See asap cries ae tke ee oS a pak de Elio ees E a A op Al E de eg oa Ms 625 o qe S A IA ee oe EA ero Tp IS IA Y ie lo ie ae B a EA 10 50 100 150 200 250 300 PAGE 38 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 6 Click on the graphics window to
74. 0 dB Logarithmic rule For energy summation spectra overall quantities 40 dB 40 dB 43 dB For amplitude summation signal 40 dB 40 dB 46 dB 4 6 5 1 Addition Operator PLUS This processing sums up all the selected quantities The user may choose either to perform an algebraic or logarithmic sum The following dialog box appears on screen PLUS_0 Addition In the Configuration tab the following analysis parameters may be defined Operator Configuration Notification Arithmetic Algebraic rule Amplitude 40 de 40 dB 80 de Energy 40 dB 40 de 80 de Algebraic rule Select the algebraic rule for an algebraic summation of data items Logarithmic rule Select the logarithmic rule for an energetic summation of data items Amplitude 40 dB 40 dB 46 dE Energy 400B 40 dB 43 db If the box Ignore erroneous values is ticked frequency bands that present erroneous values are still computed There are not computed no value if the box is not ticked T Ignore erroneous values e Save the result Annuler The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Arithmetic__________________ Default name PLUS_0 Ll Activefor At least 2 signals autospectra Leq Leq Peak Slow Fast etc If signals same physical units sampling frequency and references Restrictions If Leq
75. 0 mA in order to power supply various elements of the physical remote controls connected to it PAGE 175 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 4 Remote control examples In this paragraph we give several examples to define configure and use a remote control object in the application software dBFA All the electrical drawings of the physical remote controls evoked are also given Specific remote control for sound intensity and sound power according to 1509614 measurement with a GRAS 50AI sound intensity probe 1 button 2 LEDs remote control to manually start signal acquisition 2 buttons 2 LEDs remote control for real time acquisition 10 4 1 Specific remote control of measurement process with a 50AI sound intensity probe If you are using a sound intensity probe type GRAS 50AI with a remote control the measurement process is simplified because the operator does not need to use the keyboard or the mouse to start stop validate a measurement The remote control is very useful if the source under test is located at a certain height or in a location difficult to access The photograph shown aside features the sound intensity probe 5OAI with the connection box for the Symphonie acquisition platform The handle of the sound intensity probe features two remote control buttons that can be used to pilot the acquisition process and two LEDs to inform the user on the measurement progress The upper button blue is a
76. 0000 PAGE 36 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A O Harmonic and sideband cursors Principle and operating mode In the case of harmonic cursors the purpose is to find the fundamental frequency and the harmonics of a phenomenon and then to get closer to the exact value of the said phenomenon using an interpolation calculation depending on the FFT weighting window and on the peak shape since the exact value is never located exactly on a FFT calculation line in the case of periodic phenomena In the case of sideband cursors the aim is to find the exact value of the main carrier frequency of a phenomenon modulated in amplitude and or in frequency by another phenomenon side bands The following steps are required for the detection and the calculation of harmonics 0 Spot the fundamental frequency on the spectrum Visually adjust harmonic cursors with a displacement step in percent of the spectrum FFT resolution Indeed if the displacement of the fundamental frequency is carried out by steps of one 100 then for the displacement of 1 FFT line harmonic 10 moves by 10 FFT lines For each cursor displacement dBFA searches for a significant harmonic The significant harmonic is that highest in frequency and closest to a maximum see emergence criteria within the limit set by the user in percent of the FFT resolution This harmonic will be used as a reference for the interpolation calculation Precision on the detection
77. 1 53 22 1st channel location Point 1 Channel s 1 dB Ref 2 00e 05 Pa PWR 100 63 0 z A Tomality 000 0 E 250 637 as oe e a Articulation Index Rooms 57 00 fo 125k 61 2 1 6 k 61 0 3k 613 Table of results for psychoacoustic criteria 2 5 k 50 5 A 7158 Lin fa Table of results for broad band spectra The toolbar of the table of results allows the user to perform the following operations ay Definition Editing of data parameters for the Automatically adjust the window size to the table size table of results The levels are calculated from international system units IS It is possible to modify the default values with the command Preferences Units management See paragraph 11 1 PAGE 46 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 4 1 1 Data parameters for the table of results de Define data parameters for the table of results using the a command Listing Parameters The following dialog box appears on screen This command only applies to broad band spectra The tabs within this dialog box are used to define the following parameters TT Fized by default To set the default parameters check the box and click on OK Apply or Apply to all X axis Frequencies tab Display parameters setup x Frequencies Data Overall levels as In this tab select the minimum and maximum frequency bands for Min 16 z spectrum data values in the table of results iv Al If the All box is ticked
78. 20108 0 ref H is the modulus of the frequency response function The phase of the result expressed in radians is equal to The opposite of the Gxy cross spectrum phase Frequency response function H2 If x is the input signal and y the output signal of the process the frequency response cross function is defined based on the cross spectrum Gxy and the autospectrum Gyy This is obtained by multiplying each side of the initial equation for the frequency response function H f by the conjugated Fourier transform of Y f i e Y f It is called H H2 Gyy Gyx The modulus of the result expressed in dB is equal to H Aref Y ref 20 log H is the modulus of the frequency response function If the selected physical unit is not the IS unit and if a conversion factor Cx is calculated e g Cx 9 81 for an acceleration level expressed in g then the expression above becomes H My het Cay x ref 20 logo The phase of the result expressed in radians is equal to The phase of cross spectrum Gxy or the opposite of the phase of cross spectrum Gyx PAGE 100 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Inverse cross transfer function 1 H2 If x is the input signal and y the output signal of the process the inverse cross transfer function 1 H2 is defined as the cross spectrum Gyx and the autospectrum Gyy 1 H2 Gyx Gyy The modulus of the result expressed in dB is equal to
79. 7 mont e moteur gt Voie 2 Autospectrum Leg Lin 18 12 95 16 26 29 Global RPM Leg Lin 18 12 95 16 26 29 Global RPM Leg Lin 18 12 95 16 26 29 Global RPM Leg Lin 18 12 95 16 26 29 PAGE 159 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 9 1 Post processing analysis To create a new post processing order extraction configuration use the Analysis New analysis set up command To save display and measurement parameters in a BOE file use File Save as It is thus possible to load an analysis with the exact same configuration as that of the recording Analysis Open analysis set up 9 1 1 Description of the analysis window In the post processing order extraction module it is possible to display in the same window the overall level and the order history as well as a sonagram calculates according to the analysis parameters defined by the operator Display toolbar Display parameters BOE1 Action toolbar Acquisition storage and analysis parameters and commands for measurement control Monitoring Bac a te ran Hz 08 MATADO i AMEN 1250 000 50 00 1000 000 00 00 500 000 0 00 0 000 50 00 1000 3000 Commentaire Etat D cision Status bar enter a comment view the progress of the analysis and the number of elements remaining to acquire process The following operations are available from the Display toolbar in the order extraction window Manual setting of the display dynamics
80. AM_BBN_1100 CMG q 800 1200 s00 Display parameters setup Frequency Data Graphics Modulus j Polar Complex I Optimi Spectral units v Optimize lPwR y PWA y Dynamic dB de y Min I 1 0 Max feo Dynamic Degrees Min 180 Max 75 J Fixer par d faut Annuler Appliquer Appliquer tous 1200 LJ Graphe spectre BEAM_BBN_1100 CMG i Representation of the phase in unfolded mode Display parameters setup x Frequency Data Graphics Modulus j Polar Complex I Optimi Spectral units v Optimize lPwR y PWA y Dynamic dB de y Min Max fao 0 m Dynamic Extended degrees Ez y Min AE Max j 70 Degrees Radians OK Annuler Appliquer Appliquer tous Fixer par d faut LJ Graphe spectre BEAM_BBN_1100 CMG hy 1000 1200 Display parameters setup xj Frequency Data Graphics Modulus Polar Complex Spectral units IV Optimize Dynamic m s N fi It Y Dynamic m s N fin Min U5te 02 Max 7 05e 01 Annuler Appliquer Appliquer tous Fixer par d faut Refer to paragraphs 11 3 and 11 4 for a detailed list of the frequency weightings and spectral units available in dBFA PAGE 34 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Overall levels tab Display parameters setup x Frequency Data Overall levels Graphics In this tab select the
81. Autospectra m s m s x CANDIA mel e Legend Jerk m s Acceleration m s Velocity m s Displacement m The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Integration derivation FBID_0O Acceleration velocity and displacement autospectra and cross spectra Apply for one item only The total number of derivations and integration must be compatible with the physical units of the data items Jerk acceleration velocity and displacement autospectra and cross spectra PAGE 98 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 4 Frequency response functions 4 6 4 1 Theory These operators allow the user to compute various transfer functions and associated cross spectrum from two autospectra Channel 1 and Channel 2 and a cross spectrum Each quantity is defined below Cross spectrum G21 Gyx The cross spectrum Gyx of channels x and y is computed from the cross spectrum Gxy by the formula 2 2 x Gyx Gxy then G f 2 X f Y f Where Gxy is the associated complex of Gxy same real part opposed imaginary part The modulus of the result expressed in dB is equal to 10 log LH 10 log ELA ref gt ref ref rep If the selected physical unit is not the IS unit and if a conversion factor Cx is calculated e g Cx 9 81 for an acceleration level expressed in g then the expression above becomes u
82. Communication matlab Operator oooococcccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninininss 122 Bold Type SIGN A dla 125 Abades DPS GLOBALE tt ne Cae OT ne Oe Oe ene cae an eee ee eee eae cee ee 123 kolke Type BROADBAND SPEC TRUM ici 126 KOLS ype BARK BANDS PE CTRA de clica 126 KOTO Type NARROW BAND SPECTRUM usa ts ld a ak lla Re do 127 4 6 11 7 Type COMPLEX NARROW BAND SPECTRUM eooooocccnnnconononnnnnncnonononnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnananonnnnnnnos 127 EOTS impor Matlab results MBA tado 128 SN 128 4 6 12 TAHOMA dt Ce Nie aac LR Rs dahil a Soe 129 46121 Order extraction optar OO brisun EE ees te ocan lity cau vane ee easton 129 A6122 Orden Phase Extraction DAR Uli eee et 130 4 6 12 3 Order extraction by successive levels Operator EOP MULT ooocccnnnnnnnnnnnnnonononononononnnnnonnnnnnnnnnnnnnnnnnnnnnos 131 4 6 12 4 Calculation of order spectra by TFD Operator OA DFT cocccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninnnnnos 132 AO NAS Onder Tenn operatora E E RA 133 40 12 20 CYCIe deleChO DeralOn aia a rin a a o isa e ia a id a 133 5 BATCH PROCESSING n a A A A A 135 Sl OVERVIEW eener EE ASA E EEE 135 3 2 SOMMAR CA r AE saison ig neuio k ve eon S 135 5 3 COMPLETE PROCEDURE A E E E O 135 aoe COMPLETE PROCEDURE ion 136 6 MEASUREMENT HARDWARE CONFIGURATION ocococcococococconoronononennnnnnonenenrnnnnn nn nen enn nn nenrnrnena
83. D DBFA siii dis 167 10 1 DEFINITION OF A GENERIC REMOTE CONTROL OBJECT ssssceecceccceeeeeeseeeeestesssscccaceeeeeeeeeeeseseeeetsneaees 168 10 1 1 Selection of a generic remote CONV dos ae ta lis 169 10 1 2 Configuration Of a generic remote control oooooocccccnnnnnnnnnnnnnnnnnnnonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninoss 169 lOdJ 3 Assionment OF input JUNCTIONS LA A A E A A RE 170 IOA Assienment of OULPUL UCT ONS scr dl A 171 10 1 5 COD CV ATIVE DOCES ld a a ita a dd e Leda A P72 LO 2s JIDESCRIP TION ER IDE C15 ZIN a de eS 173 Ds COMMUNICATION UN TB RR AC B30 oust e dels 174 10 3 1 For a RS232 9 pin serial port male connector on the PC iiinnininiiciccucucaoanananananananan nono n nn nro non nn nono 174 10 3 2 For SYMPHONIE digital inputs outputs female MiniDyn connector uiinnnnnnnnnnccuuaananananananan ono nos 17D ROA REMOTE CONTROL EXAMPLES atari econo eo ooo stented as haunt ancantadet wate scans 176 10 4 1 Specific remote control of measurement process with a 50AI sound intensity probe on 176 10 4 1 1 Choice and configuration of the remote control object occccccnccccncconononononnnnnnnnnnnnninnnnnnnnnnnnnnnnnnnnnnnnnnnnnnns 177 104 122 CONNECTION ANA operatine A a aia 177 TL APPENDICES ou aa IA AA a A A a ia 179 BEE AMPORTINE DA TAFILES oi o a in Meda ii ans ect 179 Ez IMPORE NAS OR N URFORMA Ti tl Dto ab aici ee tion acer 180 11 3 FREQUENCI WEIGHT OS illa atada t
84. DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 2 3 Averaging parameters Use the command L Config Average to define the averaging parameters of the ines Lines measurement The dialogue box shown opposite appears on screen Mo of averages 30 Time eee 0 600 This dialogue box allows the user to modify the type of averaging and the number of averages or the measurement duration There are 2 main types of averaging Linear This averaging mode gives the same weighting to all samples which means a linear average on N samples that stops as far as the N sample is reached Exponential This averaging mode gives the highest weighting to the last reached sample and reduce progressively the influence of the previous samples An exponential average does not stop In this dialogue box the user can modify the number of averages to take fe Ho of averages 20 into account and the averaging duration These two parameters are linked by the general acquisition parameters number of lines pass band Time sec 0 600 Cancel 8 2 4 Internal signal generator option Use the command Config Generator in order to define and activate the internal signal generator The following dialogue box appears on screen Generator Using dBFA with the SYMPHONIE or HARMONIE hardware platforms a white noise pink es noise a sinus signal whose frequency we define can be generated e ooti Signal Choose the option Loop to lo
85. Log or decibels dB for Dynamic dB data display dB nd Min 2 Max 1 0 Dynamic D egrees Degrees y Min 180 00 Max f 50 00 Annuler Appliquer Appliquer 4 tous Fixer par d faut Select the spectral unit RMS or PWR for broad band spectra and multispectra as well as the weighting to apply to all spectral data If the Optimise box is not checked then minimum and maximum values of the display dynamic range can be set here PAGE 44 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Refer to Sections 11 3 and 11 4 for a detailed list of frequency weightings and types of spectral units available in ABFA In this view the parameters for the modulus phase or real imaginary complex views are dissociated from the Nichols or Nyquist views It is then possible that both the Modulus phase view and the Nyquist view are displayed at the same time To avoid this click on the Apply to all button so that the transition from Nichols to Nyquist is applied to both views Otherwise remember to apply the same parameters on both views aplaque_pri CMG 2 Ban OOOO 0 7 i ERE AMET AAN HT Nichols or Modulus phase Nyquist view view or real imaginary complex view gt 26 03 02 10 14 50 000 0s000 3 3 6 Lissajous view This type of view displays the Lissajous representation between two signals To view the Lissajous representation select two Signal items and go to Datafile Lissajous An
86. TE USER MANUAL gb_dBFA NUT 043 A 3 3 2 Broad band spectra and or multispectra Bark bands histograms and echogram This type of view is used to graphically display spectra and or multispectra in broad bands octaves third octaves and 1 Nth octaves in Bark bands psychoacoustic as well as echograms and histograms For multispectra a spectrum calculated for each integration step defined by the user a scrolling bar at the bottom of the view is shown in order to view the spectral quantity at different time periods An example of this type of view is given below Definition of data display parameters dynamic range overall levels cursor synchro __ Display spectrum CMG1 e o x El as EN A Delta Y ID 7 0 7 ID 7 G2 Surpresseurs gt Channel2 Hz dB 2 000e 05 Pa PWR MI EE HEE EES EE Display of overall levels Display of spectra echograms or histograms on the same graphical view 8k 16 k Lin gt 29102 16 35 56 375 55375 Scrolling bar for mulltispectrum view with indication of the duration The toolbar of the graphical view allows the user to perform the following operations ay Definition Editing of data parameters for the Kl Definition Editiing of display parameters for the graphical view graphical view rl Go to stacked superimposed mode if several curves iio bas with the same characteristics are displayed er ae Activation Deactivation of Lin overall level display
87. UFF format Universal File Format 58 3 7 7 Exporting data in Lexade format Exploitation and Analysis of Test Data eee 58 3 7 8 Exporting data in ME scope format Modal analysis software oooonnnnnnnnnnnncicncocconanananoon ono nnnnnnnnnnnnnnnnos 58 S29 sEXDOMUNG Gath MA TEARS TOMOT dd 58 3 7 10 Custom SaUn o ABLA dial 59 O E Measurement session SCHEKAL ODILONS dd dd alla 59 4 OFF LINE PROCESSING i sssstcsesiisiscciaanusrcacsnncsnsdanassnncaieanadauus eaddaneennndadewendaaniaadeassnscadanudenadaamasentaneaasuts 61 4 1 INTRODUC TON rnin N E iu ats cas veered pea acta a E EEEE 61 4 2 CALCULATION SER VER OVERVIEW ea 62 4 3 OVERVIEW AND CONFIGURATION OF ANALYSIS SCRIPTS cooocococnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nana 64 4 4 LISING SHORTCUTS TOR UN SCRIPTS etude cect eeiibesadaeaactnecatesinean factuentiemneene 65 Alis ASS COS OPUS e an oe re ee 65 2 EI SS A EA IO 65 4 4 3 Quick editing of a script associated With a shortcut ooonnnnnnnnnuninuooooanananananan aaa 66 4 5 LIST OF DEFAULT ANALYSIS SCRIPTS AND ASSOCIATED OPERATORS PROCESSING FUNCTIONS coocccocccno 66 4 6 OVERVIEW AND CONFIGURATION OF OPERATORS PROCESSING FUNCTIONS ccccccccssssseecceeeeeeaseeeeeeeeeees 70 Oss PEC ISS A amnesia eae ee eeranae 71 4 6 1 1 A A nue ade hhcsche 71 Ang Ere quen Ss 73 4 6 1 2 Narrow band spectrum Operator EB reiasa aa a a a aaia 74 4 6 1 3 Narrow band Cross spectrum Operator FBG12 Peerna i n AE A EA 75 4 6 1 4 broad ba
88. _O Activefor Applies for one item only Result family Autospectrum 4 6 1 6 Morlet wavelet transform operator Use this operator to obtain a multispectrum with a timing down to the sample and a good frequency resolution The Time Frequency ratio can reach 1 41 The dialog box below is displayed on screen In the Configuration tab the following analysis parameters may be defined MOR_0 Morlet xj Operator Setup Low frequency ill ES High frequency as s Number of channels i 2 per octave Representation Module time Averaging jo z fi me Point to point Upper Lower frequency Define maximum and minimum frequencies to study as a percentage of the sampling frequency The upper frequency cannot exceed 35 to avoid aliasing effect Number of channels per octave Define the number of channels per octave e the bandwidth in nth octave Representation Select the representation Modulus phase real part or imaginary part Time Define the timing of multispectra in milliseconds or sample by sample by checking the Point by point depends on the sampling frequency Save the result Annuler PAGE 77 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The Operator tab provides a detailed description of this type of processing and offers the possibility to modify its name Default script Signal analysis Default name Activefor Signal family Applies for one item onl R
89. a a of ee eee er er eet eee twee i Saeed tity Fa Se Bie GT ap ERAS Ae ie ae a ican A eae AT A List of the harmonics 18 x Display spectrum harm_bandlat CMG ID 32 1 250 Hz Delta f 12 5 Hz o IAE 5 PAGE 39 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 4 Sonagram view This type of view displays all narrow band autospectra with timing or other mode depending on the speed To view the sonagram first select the item and then use the Session Sonagram menu An example of a sonagram view is shown below Definition of display and cursor synchronisation parameters ME Moteur_porsche CMG Sonagram 1 Baix alle 21 Display of ID 3 G1 balayage gt Voie 1 0 a spectrum at the Sonagram display cursor Value table for cross 7 lt cursors 10s000 145500 10s000 145500 Display of level history at the cursor The toolbar of the graphic view gives access to the following operations A Cancel zoom Zoom function is accessible by Define Edit data parameters for display ag pressing on the Shift key and selecting the area with the mouse Fl oo a o Ia ome orem Cursor synchronisation between the three views p rig spectrum time history and sonagram Activate or deactivate order cursor Levels in dB are calculated with respect to the international system reference values Reference values can be modified as well as the physical units usi
90. al The filter used fulfils Type O requirements of IEC651 and equivalent standards The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name Activefor WEIAO Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families 4 6 2 7 Frequency B weighting Operator WEIB This analysis results in an B weighted time signal The filter used fulfils Type O requirements of IEC651 and equivalent standards The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name Only applies for one item Signal Impulse Response families Family of the result Signal Impulse Response families PAGE 84 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 8 Frequency C weighting Operator WEIC This analysis results in a C weighted time signal The filter used fulfils Type O requirements of IEC651 and equivalent standards The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name Activefor Only applies for one item Signal Impulse Response families Family of the result Signal Impulse Response families 4 6 2 9 Vibratory weigh
91. al to Equal to Greater than Greater than or equal to Contains the character string Vil vVVIAAA Refer to paragraphs 11 3 for a detailed list of the frequency weightings available in dBFA PAGE 53 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 6 3 Running a request ae AIID it Once all the requests have been defined use the scrolling list lis of the measurement session window or the Datafile Current request command The selected request is then executed automatically An example of execution of a request to display only items of the Signal family is given below EJEA blanc CMG Main window F Allitems gt En L 0 16 Ss A Ea 05 10 00 03 16 45 1 22050 i sanan i H 05 10 00 03 16 45 4 1 22050 Leg i ial i K 05 10 00 03 16 45 Average Leq in Peel 05 10 00 03 16 45 gt 0 125 Leg Lin al 05 10 00 03 16 45 Average Leg Lin Al 05 10 00 03 16 45 Average Leg Lin Mi 05 10 00 03 16 45 Average Leg Lin 05 10 00 03 16 45 Average Leg Lin FBH1_0 05 10 00 03 16 45 Average Instantaneous Lin SAMPL_O s om oe us 45 1 51200 Leg PL BARK_O Average Lin PS CHO_O Leq PSYEV_O Leq in PSYEV_O H6 Leq BARK_O 05 10 00 03 16 45 Leq BGLOBAL 0 05 10 00 03 16 45 Definition of a request Name Signal Conditions E E T E EE Cancel aio Signal sii Fa Data type W Name Date Dur Period v x x cf comments 0 Signal Instantaneous Lin 05 10 00 03 16 45 5851 1 22050 Paj O O
92. ally used for offices and public places Loudness spectrum in Bark bands Digital filtering 24 filters based on Butterworth filters of order 8 and for which the frequency limits correspond to the Bark bands Time history of Loudness and Sharpness criteria From a Loudness spectrum in Bark bands intermediate computation done by the operator the Bark bands are recombined to form the required criterion Before the presentation of each operator let us present theoretically each psychoacoustic quantity PAGE 110 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 7 1 Bark bands In the field of acoustics a third octave spectrum would usually be represented by narrow bands However this does not take into account the resolution frequency of the human ear It is possible to divide the audible spectrum into 24 critical or so called bark bands These have variable band widths in order to simulate human perception of sound more realistically In addition the 24 band format enables simplifications of the calculation process Values FMIN Fmax and Fc of each Bark band are N Conversion from Hertz to Barks is possible using the equation 4 6 7 2 Stationary criteria O Loudness Loudness is a measure of sound energy and is expressed in Sones It represents the intensity of the sound as perceived by the ear As a reference 1 sone is the level given by a pure sound of 1 kHz at 40 dB This level increases by powers of two In
93. alysis may result in the following stationary psychoacoustic criteria Loudness Loudness 10 Fluctuation Strength Sharpness Tonality Roughness Unbiased Annoyance Sensory Pleasing Sound Articulation index The following dialog box appears on screen PSTYCHO_O Psychoacoustic criteria Operator Configuration Notification In the Configuration tab the following analysis parameters may be defined Field e Free E Diffuse MW Loudness Tick the required boxes to calculate the corresponding psychoacoustic criteria W Tonality 5 Sensory Pleasing Sound M Roughness M Sharpness Note that Sensory Pleasing Sound Loudness Tonality Roughness and Sharpness criteria have to be computed as well ae se ad Unbiaised strength M annoyance Loudness z 10 Articulation index W HHY IY Unikeller IY Rooms Save the result Annuler The computation of the criteria Sensory Pleasing Sound also depends on the type of sound field free or diffuse Note that the computation of the criteria Unbiased Annoyance the Sharpness Fluctuation Strength and Loudness 10 criteria have to be computed as well The computation of the criteria Unbiased Annoyance also depends on the time of the day day or night H Psychoacoustic psp cmg The table shown aside is an example of results obtained after O O psychoacoustic analysis of an audio record sone aci Refer to the previous paragraph
94. ameter called Unbiased Annoyance The Unbiased Annoyance is a measure of how unpleasant the noise is perceived to be and is a combination of the previous parameters Sharpness Fluctuation Strength and Loudness 10 E Sensory Pleasing Sound SPS All the preceding parameters give an indication on the nature of the noise and its perception by human experience However it would be interesting to be able to obtain a general description Zwicker proposed a new parameter called Sensory Pleasing Sound The Sensory Pleasing Sound is a measure of how pleasant the noise is perceived to be and is a combination of the previous parameters Roughness Sharpness Tonality U Articulation index Rooms Unikeller NHV The articulation index aims to quantify the perception of fluctuating phenomena present in the studied noise This index is expressed as a where a high value indicates good audibility Three main algorithms are used to calculate these articulation indices The Rooms algorithm is used particularly for sound measurements in offices rooms and public places in general The Unikeller algorithm is a variation on the classic method developed by Beranek though here the indices are not limited to a scale ranging from 0 100 The NHV algorithm Noise Vibration and Harshness has particular relevance to the car industry PAGE 112 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 7 3 Psychoacoustic criteria Operator PSYCHO This an
95. analyses When the Simulate timing box is checked the analysis time is the same as for a real time measurement If the box is not checked the analyses takes up all the PC resources and can then go faster O Definition of data to store in the measurement session There is one column per channel Activation of analysis per Name of channel to measurement channel Channel 12 set up Analysis Definition of overall Global level analysis Overall Fein 0 000 _Overall Flax 0000 000 Definition of Global AX orders to analyse ders Lint 1 000 Scroll bar used to go b from one channel to the other Analysis Activation of analysis per measurement channel Overall Fmin and overall Fmax Frequency limits for overall level calculation Overall Activation of overall level analysis Overall weight Weighting applied to the overall level if Overall is active Order weight Weighting applied to the order calculation 1 2 8 Enter here the number of the order to extract from the analysis Orders can be non integer 8 orders maximum can be extracted PAGE 163 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Advanced parameters are used to define measurement parameters maximum frequency and number of lines according to the study to carry out Advanced parameters x Order range Order range Enter the limits for the study minimum and maximum orders to extract Min o
96. anging from octaves to 1 48th octaves with time history capability broad band multispectrum The user may either use digital filtering Class O IEC1260 or FFT synthesis Broad band spectrum FC_0 Narrow band spectrum with time history capability narrow band multispectrum and frequency zoom The user specifies the FFT window the overlap and the number of lines Narrow band spectrum FB_0 iiadercanscin Undersampled time signal fixed by the user A low pass filter DECIM f 9 Butterworth order 20 ensures anti aliasing the undersampling ratio varies between 2 and 50 sen ama Response Notch filtered time signal The user defines the filter selectivity S Notch filtering factor The frequency range at 3 dB is then of fe PI S for an order NOTCH_0 2 By increasing the order number Attenuation is emphasised at the expense of Selectivity A weighting A weighted time signal The filter used fulfils Type O requirements of WEIA_0 standard IEC651 and equivalent B weighting B weighted time signal The filter used fulfils Type O requirements of WEIB_0 standard IEC651 and equivalent C weighting C weighted time signal The filter used fulfils Type O requirements of WEIC_0 standard IEC651 and equivalent Overall level Short Legs time history of the time signal Frequency Lin A B C and LEQ_0 time Leq Peak Fast etc weightings can be applied Bark band specific Loudness with time history capability specifi
97. anns 12 Dishes OVERVIEW OF THE SOFTWARE PACKAGE PRINCIPLE OF OPERATION sseseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 12 22 MEASURNGWITHDB Perse bee aee Aa 13 2 2 1 Common steps Intensity mode Sound POweT oooooonocnnonooooaaonanononononnnnnnnnnnnnnnonon nono nnnnnrnnnnnnnnnnnnnnnnnnnnnnnos 13 Ze DATA PROCESSING WITHDBE Abeer ii 14 Dolo RECUSA AAKOO Taar TEES A o lol 15 ZOD SOMME Processing ANGIV SCS esisin REE EEA ls inde 03 16 A e A A k inlet onl ta cere sabe hee oo 18 3 MANAGEMENT OF MEASUREMENT SESSION DATAFILES CMG csccsssccssscessscnsssesensseensseenseeeneeees 20 oral CMG DATA FICE MANAGEMENT vda teo asa Geatetenanianaieeess 20 Sule NWwCMG A eoe T neice Seet hs ora neta ckt oi Dieta rial aia te 20 sda OPa CMO dala IS tee 21 ls ClOSC OSC MG QAI eer a E ele ea cece eee ode 21 A SEA CLG dad AA Nes ile asa tics O pie erent ees lesa 21 Si DetereOne OPSCVeral CMG DOTA US a A aa lea pica erence lane ssc teenie a ZT 3 2 MEASUREMENT SESSION WINDOW OVERVIEW sii ida di 22 DOL LOO VOI sea ae ae E oO As onc igo gaa Cat a as aa ag cael nao asda cee sae 22 322 Meas remenis ssio information WINDOW ise A aa 23 Ia SVICUSUTCIMCIIESCS STONCOMMCRES SS is 23 JaA Playback OF nalr e cordino S eenn SA NS A cee eee 23 un D AN E EEE EE E A R 23 Sud Mod y dala OMS COUNT nain a a a ae ee ae 24 3 2 6 1 Editino OF items date and tine seieren er A LEE dai 24 3 2 6 2 Editing OF lems location and COMMEN aan 24 3 2 6 3 Edil
98. aragraph 2 3 2 for more details on how to configure an analysis script Be careful the title bar of the calculation server must feature PILOTE BATCH FOR in order to configure and run an analysis script in the batch mode If this text is not displayed click again on the batch dialog box PAGE 18 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A UU Stage 4 Execution of the batch processing Once the set up operations have been carried out validate all the dialog boxes and click on the corresponding icon to start the batch analysis The different processing operations of the analysis script are executed for the data items grouped and locked in the batch dialog box The analysis results are then stored in the active measurement session datafile Refer to chapter 5 for more details on the batch analysis process PAGE 19 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 MANAGEMENT OF MEASUREMENT SESSION DATAFILES CMG Any data acquired in dBFA is stored in a measurement session datafile CMG extension From this datafile the user can perform a given analysis for example calculation of a narrow band average spectrum from a signal recording From the measurement session window it is possible to print tables of results and graphics to copy and paste data items to a spreadsheet or word processor for further analysis and for editing a measurement report This chapter deals with the following aspects of data processing Ge
99. are in text format example 50Hz fa psy cmg Listage A x E a Graphe spectre Cmg Exemple CMG OF x D 01dB 01d6 programs 32bit databin psy cmyg Famille Grandeur Date Lieu 1ere voie ID 112 dB Ref 2 00e 11 Pa m s PWR Hz 1707 Dur e Voie s 63 0 ness 2757 oe acum F 624 Fluctuation Strength vacil F 643 Graphe audio Cmg Exemple CMG 63 7 63 4 62 4 639 Tonality RR Unbiased Annoyance 26803 au FO Sensory Pleasantness 0 00 oe 63 5 Articulation Index Unikelen 41 15 62 7 Articulation Index Rooms 57 00 612 Copy Values Copy Image a W Microsoft Word Document6 Preview mE Word Document6 Preview A ES E O x File Edit View Insert Format Tools Table Window Help D Els F 31108 o gt Pag E chose R jose Sar ias o O Arial 110 B O A gt e gt 9 2 00 ron e 5 1 Loudness 41 57 sone F 2 Sharpness 1 57 acum F 3 Fluctuatior 1 49 vacil F 4 Tonality 0 17 tu F 5 Roughness 1 08 asper 6 Unbiased 4321 00 au FD 7 Sensory P0 08 pu F 8 Loudness 56 05 sone F Articulatior 59 85 10 Articulatior64 04 11 Articulatior 71 00 14 4 bi Sheet1 f Sheet2 Shee 4 Ais NUM Page 1 Sec 1 1 2 t 26 2cm Ln 2 Col 1 PAGE 56 DBFA SUITE
100. as been defined For items where a study zone can be defined an audio signal for example it is possible to copy the image of the view over the complete duration of the item option Copy the whole or to copy only the image of the view over the defined study zone Copy only the study zone ie vertical horizontal To obtain frequency values in digital format after broad band spectra export add in dBFA ini file the following heading Export LabelFreqNum 1 If LabelFrqNum 0 frequency values are in text format example 50Hz The default option Be prompted for the type of copy each time allows the user to display a message to either copy the image of the view over the complete duration or the study zone The following message appears on screen x Some selected items have a study zone already defined Do vou wish to copy only this zone E on Annuler See paragraph 3 2 6 for more details on defining a study zone Copy data items in ASCII format When copying directly data items from the measurement session window in ASCII format an additional parameter is the way it will be pasted in a word or spreadsheet processor It is also possible to export data in dB or in physical unit Select this option using the Preferences Units management menu see Section 19 1 The data values can be displayed vertically default value data of X axis and Y axis are displayed in columns Alternatively they can be displayed
101. ase correction during intensity measurements After selecting this option it is necessary to load the phase correction file AU corresponding to the used probe using the selection button gt gt The tab of the dialogue box shown above indicates the file of the selected phase correction The calibration files of the probe AU may be defined in the program dBSONDE The user may whether input the residual space manually with the calibration chart of the manufacturer or measure it PAGE 140 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 7 MEASUREMENT CHAIN CALIBRATION This chapter concerns only intensity and Sound power ISO9614 modes Calibration is recommended before every measurement Calibration guarantees the reliability of the results Calibration affects the sensitivity of the selected transducer by adjusting it as a function of measured and expected values defined by the frequency and level characteristics of the calibrator The calibrators and transducers are defined by using dBCONFIG and they are selected using the Hardware configuration command in the Acquisition menu The current calibration is done using Leq over a 125 millisecond period It measures the Leq value of the input signal and converts it into the unit set in the transducer s characteristics By adjusting the level to the expected level it changes the sensitivity of the transducer By validating it the adjusted value will now become the default value for
102. ata items in a measurement session datafile To configure processing functions in an analysis script To execute an analysis script with the calculation server To import 16 bit datafiles for users of 01dB Metravib PC based systems with 16 bit version software packages To export audio signal events at the Microsoft WAV format To edit a measurement test report The first action for data analysis is to open an existing measurement session command File Open that contains the measurement data items to analyse PAGE 14 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 3 1 Requests data sorting Measurement session datafiles have a structure similar to databases As any measurement result is stored into these datafiles a set of requests functions allow the user to sort the data according to various parameters One can display for example data items of the same family only signals narrow band spectra octaves and third octave spectra etc in the measurement session view See chapter 3 6 for more details UU Stage 1 Editing of requests Use the command Datafile Edition of requests to open the dialog box that allows the user to define edit or remove requests dBFA manages two types of requests local requests which apply only to the active measurement session and global requests which apply to any measurement session The procedure to define a request is the same in both cases Follow the instructions below to add a
103. ation re sampling denoising tachometric conversion convolution Operations on spectra Theory frequency recomposition in broad bands and Loudness Bark bands time recomposition integration derivation Transfer functions Theory cross spectra transfer functions and coherence Arithmetic Theory addition subtraction and averaging Time history of an overall quantity Theory Short Leq time history Extraction of Leq level from a multispectrum Extraction of a Loudness level from a multispectrum in bark bands Psychoacoustics Theory stationary psychoacoustic criteria spectra in bark bands specific Loudness time history of psychoacoustic criteria Audio data export Theory export to MATLAB format to WAV 01dB Metravib format and to MP3 format Operations on overall levels Theory histograms E Room acoustics Theory echogram Tachometry Theory order extraction order filtering cycle defects PAGE 70 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 1 Spectral analysis 4 6 1 1 Theory Three types of analysis allow the user to estimate the averaged or instantaneous frequency contents of a signal narrow band analysis broad band analysis and Time frequency Analysis Narrow band analysis based on a classical periodogram Welch Wosa or Gabor analysis with selection of an overlap a weighting window and a zoom factor A time integration can be selected to generate a multispectrum This
104. ay Curves to define the data to display in the measurement window The following dialogue box appears on screen Curves display Gxx Autospectra Gxy Cross spectra sxx 13 xx 2nd pass xx 2nd pass Li Active intensity Lj Reactive intensity SIL Free field intensity Ls Lp Mean pressure 1st pass first FFT pass narrow bands 2nd pass second FFT pass narrow bands Cancel 1 1 octave bands 1 3 third octave bands 4 O Choose the quantities to be displayed in the list of available quantities For the real time intensity mode the user may display the following data Cross function deactivated Cross function activated Li pass 1 Li pass 2 Li 1 3 Li 1 1 Lj pass 1 Lj pass 2 Lj 1 3 Lj 1 1 Autospectra for each measurement channel Gxx Cross spectra Gxy pass 1 Gxy pass 2 pass 1 Gxx pass 2 Gxx 1 3 Gxx 1 1 coherence 1 coherence 2 SIL pass 1 SIL pass 2 SIL 1 3 SIL 1 1 Lp pass 1 Lp pass 2 Lp 1 3 Lp 1 1 O The right column of the dialogue box allows to combine the previous chosen quantities with the selected measurement channel s Example If working with two channels this column allows to choose the autospectrum display of the wanted channels The curves which will appear on the display are the curves displayed in the left column of the dialogue box Use the button View in order to add a new spectrum line to the list To superimpose a spectrum in an existing line use the butto
105. band depends on the microphone spacing of the selected minimum frequency and the activation or deactivation of the convolution correction If the option Full octaves is activated the pass band is reduced to contain only the full octaves The minimum frequency is replaced by the minimum value of the upper octave band The maximum frequency is replaces by the maximum value of the lower octave band PAGE 146 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Input The programme allows the user to choose between AC or DC input With this option the continuous component of the signal can pass or not By using the AC input a 0 5 Hz high pass filter is included in the signal chain When the option AC is chosen it is necessary to use specific cables Physical quantities The microphone spacing is only needed for the calculation of sound intensity level Li Lp Lj SIL with a sound intensity probe It has an influence to the measurable frequency range according to the table below The table below summarises these interactions for various microphone spacing The value between brackets gives the high frequency limit when the convolution correction is activated Fmin Hz gt 20 25 to 40 50 to 80 100 and Spacing mm 1 6K 1 6K 2 5K 3 15K 100 4K 6 3K lll a ea 100 2K 100 4K 100 8K 100 8K 2K 4K 8K 12 5K The physical limitation of the frequency range is due for high frequencies to the approximation of the p
106. bine spectra or multispectra with a lower frequency resolution The synthesis of a broad band spectrum into another broad band spectrum is classical For example the recombination of a third octave band spectrum into an octave spectrum is done by the energetic sum of the 3 third octave bands that would be part of an octave band For synthesis of a narrow band spectrum into a broad band spectrum the energetic summation is allowed only if there is at least 5 narrow bands to sum those lying in the frequency limits of the broad band Time recombination From multispectra in narrow bands or in broad bands it is possible to perform various time operations LJ Recombination according to a greater time base LJ Extraction of maximum minimum and averaged spectra LJ Extraction of an instantaneous spectrum whose overall level satisfies a given criterion minimum maximum weighted or not Integration derivation Spectra in narrow bands autospectra and cross spectra which physical unit that can be integrated or derived jerk acceleration velocity displacement can integrated or derived according to the following formula Y is the result X is the input Derivation n times YP G2af XY Integration n times l Y f X V GTS f A cross spectrum that results from the computation of velocity and displacement spectra for example can therefore be integrated once for one quantity velocity and be derived twice
107. by input 5 2 Summary The procedure for using batch scripts is summarised in the scheme below E Demo CMG Main window Al items y JE Sel 6 9 S i Family Datatype w Date location Period 1 0 Signal Instantaneous Lin 30 10 02 16 56 14 Surpresseurs gt Channel 1 10 1 51200 Signal Instantaneous Lin 30 10 02 16 56 14 Surpresseurs gt Channel 2 10 151200 Speed profile Instantaneous 30 10 02 16 56 14 Surpresseurs gt Channel Tachometry 1 50 A et lee Signal Instantaneous 30 10 02 16 56 27 Surpresseurs gt Channel 1 10 1 51200 Add calculated elements Signal Instantaneous 30 10 02 16 56 27 Surpresseurs gt Channel 2 10 1451200 Speed profile Instantaneous 30 10 02 16 56 27 Surpresseurs gt Channel Tachometry 1 50 Signal Instantaneous 30 10 02 16 56 38 Surpresseurs gt Channel 1 10 1 1200 to the session Launch operations 1 Signal Instantaneous 30 10 02 16 56 38 Surpresseurs gt Channel 2 Peles Select items in the measurement session Signal analysis y No operation in progress 2 91dB Stell l Select processing to repeat for Launch operation server each selected item m mE Launch aax Export batch aid am No operation in progress 4 OI B Stell gt x no ID Origin Status 1 Demo CMG Todo f E 2 1 Demo CMG Tod The server presents scripts that can be applied Silos ts cd to the set of selected items Import element to 4 4 Demo CMG Todo A batch must
108. c Specific Loudness Loudness multispectrum a time step lt 50 ms is required for later BARK_0 psychoacoustic criteria computation The result is expressed in sones according to Zwicker B AUDIO ANALYSIS i Leq family Overall noise quantity integrated over time Short Leq Fast Slow Impulse etc PAGE 68 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Operator mes Default name Description Result Peychoacoustic criteria Stationary psychoacoustic criteria Loudness Loudness 10 J PSYCHO_0 Fluctuation Strength Sharpness Tonality Roughness Unbiased Annoyance Sensory Pleasing Sound and Articulation Index o Octave or third octave echogram Evolution of psychoacoustic criteria PSYEV_0 time history of a psychoacoustic quantity Loudness Zwicker B Sharpness User defined time weighting window on a time signal defined with Windowing segments of classical windows Hanning Rectangular Flat Top WIN_0 etc Gain optimisation This processing amplifies time signal DAC data in order to optimise GAIN_0 for example the replay level The physical level remains unchanged Re sampling This processing re samples the audio signal to a frequency specified 1 Signal item SAMPL_0 by the user or an Impulse A i Response apon transform PEE CAPON_0 This processing calculates the Capon time frequency transform Denoising This processing performs denoising of a signal by DENOIS_0 decomposition recompos
109. c device attached to the acquisition peripheral Triggering signal recordings from a simple one button physical remote control The electrical drawings of the physical remote controls and the communication interfaces RS232 port SYMPHONIE or HARMONIE digital inputs outputs are also given PAGE 167 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 1 Definition of a generic remote control object Physical remote control Application software Input 1 Contacti Put messages that i initiate an action into the measurement software INPUTS E 3 states e g push buttons Communication e g start storing data interface RS232 serial port or Output 1 Digital 1 0 of Contact 1 Output messages that SYMPHONIE or initiate an action onto the HARMONIE 4 states physical remote control OUTPUTS e g LEDs flashing Output 2 light e g a LED is blinking A generic remote control object for 01dB Metravib programs is made of 2 physical inputs and 2 physical outputs It features 16 input functions and 16 output functions each one of them having a START and a STOP state It means that 32 input messages can be received by an application software by mean of the remote control object to remotely control the measurement for example and 32 output messages can be sent by the application software to a physical remote control to trigger a light alarm for example Messages are assigned t
110. cf m The type of hardware platform m The active measurement channels Hardware peripheral Remote control Phase conection m For each channel a couple transducer calibrator of same type SYMPHONIE gt Configuration m The signal conditioning options of the selected hardware Channels peripheral Configuration key Minimum 1 Maximum 2 Ho Transducer Calibrator Act The hardware configuration defined here will be recalled automatically next time the program is used DJB A120 NA E Micro 1 2V Pressure Sd The acquisition platforms transducers and calibrators are and Calibrat Disabl Transducer Calibrator Disable selected from hardware elements databases defined under the M Tachometric transducer hardware configuration programme dBCONFIG Tacky 60 4000 gt Selection use and configuration of remote controls are Ered dealt with in chapter 10 Hardware The hardware board configuration sets up the computer so that it will be able to record data generated by the specified board It sets the number of possible active channels The Configuration key gives access to signal conditioning options built in the hardware unit Active channels Among the possible channel s available on the acquisition unit define which channels will be active for both acquisition and calibration Transducer The transducer configuration loads the transfer function of the selected transducer and allows the conversion o
111. cy of the item unite string table that identifies the unit in which the quantity is expressed After this display and after deleting the item in dBFA the variable remains valid in the MATLAB workspace Only closing MATLAB or a clear command dBID6 will delete these data PAGE 123 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The MATLAB command window displays the list of available variables if typing the command who who Your variables are dBID6 Then we can use this data as all MATLAB data As follows maximal and averaged value for example max dBID6 ans 0 1914 mean dBID6 ans 1 8266e 007 The file name m is obviously free Only the syntax is to respect number of parameters and type All MATLAB errors are transferred to dBFA and indicated to the user in case of a faulty syntax or an incorrect use of parameters We change the MaVisuPourAudios file as follows for example function MaVisuPourAudios ID nom fe unite other figure nb size ID t 1 1 nb 1 vect_t t fe plot vect_t real ID xlabel Time ylabel unite title nom dBFa32 A The result is then ERR 22037 AN Erreur dans une commande Matlab Communication matlab MATCO_O 727 Error using gt mavyisupouraudios Too many input arguments PAGE 124 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 11 2 Type SIGNAL Syntax function xxx ID nom fe unite ID identifier of the variable dBID n
112. d or narrow band multispectrum on a different time basis Calculation of minimum maximum averaged spectrum Extraction of an instantaneous spectrum for which the overall level meets user defined criteria Time recomposition RECOMPT_0 Autospectrum Intensity active reactive free field Overall level time history Time history of the overall level of a multispectrum with frequency GLOBAL_0 weighting SPECTRA OPERATIONS Cepstrum This process calculates the cepstrum from a narrow band average CEPS_0 spectrum PAGE 66 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Operator Default name Cross spectrum G21 This processing produces from a cross spectrum the cross FBG21_0 spectrum defined as its associated complex This processing produces from the autospectrum Gxx of the input signal and the cross spectrum Gxy between the input and the output the transfer function defined by Gxy Gxx Description Result Transfer function FBH1_0 This processing produces from the autospectrum Gxx of the input signal and the cross spectrum Gxy between the input and the Autospectrum output the transfer function defined by Gxx Gxy Channel 1 Autospectrum This processing produces from the autospectrum Gyy of the Chamnel 2 output signal and the cross spectrum Gxy between the input and Cross the output the transfer function defined by Gyy Gyx spectrum Ch 1 Ch 2 Inverse transfer funct
113. dBFA software suite Frequency Analysis and much more 155 Mode Intensim trie INT ue f Jete 2 fue Jia lo E G1 11 dB Ref2 00e 05 Pa RMS Hz EN EEE 4k 8k Trigger Manuel E psy cmg Main window OF Xx ean items date type E a HAME 1 6 8 1 Famil Data type Tagg Thane Date Duration Period Y axis X axis Track E OR A 15 Audio _ ins Lin 11 07 97 01 51 22 20 920 11 10240 Pa_ 6 Psycho PSYCHO O 11 07 97 01 51 22 PSYCHO 05 7 Bark spectrum Leq PL BARK_O 11 07 97 01 51 22 20 900 0 020 sone F Bark 1 BARK_O 5 B Leg Leg PL PSYEV_O 11 07 97 01 51 22 20 900 0 020 sone F 1 PSYEV_O 5 9 Leg Leg Lin PSYEY 1 11 07 97 01 51 22 20 900 0 020 acum 1 PSYEV_1 5 10 Leg Leq PL SY Driver Bruit_blanc CMG EIEIXIpo sone F 1 BGLOBAL_ Signal analysis y E un FR O from Bruit_blanc i TAI Signal plot Cmg Exemple CMG __ Graphe spectre Cmg Exemple CMG __ Graphe spectre Cmg Exemple CMG dB Ref 2 00e 05 Pa PWR Hz EWES WIPER PN IET ID 166 Ch 2 O mss X ERD y1 MA 4000 6000 s000 10000 2000 3000 4000 AREVA O1dB Metravib USER MANUAL DBFA SUITE USER MANUAL gb_dBFA NUT 043 A TABLE OF CONTENTS PAGE 3 DBFA SUITE USER MANUAL 01dB Italia s r l Via Antoniana 278 35011 Campodarsego ITALY 39 049 92 00 966 39 049 92 01 239 yu O1dB Metravib A AREVA Copyright gb_dBFA NUT 043 A
114. e Sine LFM Wi file m The gain is the only parameter that can be set for the generation of white noise A gain of O dB corresponds to the Gain dB jo maximum amplitude that can be generated by a sound card without saturation depending on the model d Once signal parameters are set use to launch the emission 11 8 4 Generating sine noise Click on Sine to generate a Sine Several different frequencies can be generated simultaneously on the same channel and each channel can be set up separately White noze Pink nose Sj LFA WHAM file dd Identical channels Channel No If at least 2 channels are used different signals can be generated on each channel Select the channel to configure if you wish to configure each channel independently channel no Identical channels 2 Number of zine channel 2 Sine parameters 2 yore 2 Frequency Hz f 000 Gain dB o Initial phase 5 lo Number of sine channel Indicate the number of sine to generate on each channel Sine no To configure each frequency select the no of the sine to configure Parameter of sine X on channel X Enter the frequency the initial phase and the gain or the selected sine PAGE 188 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A p Once signal parameters are set use to launch the emission 11 8 5 Generating frequency modulation Click on the MLF tab to generate a frequency modulation A differ
115. e only autospectra in narrow bands first and second FFT passes and in octave and third octave bands can be measured 8 2 2 Acquisition parameters Use the command Config Parameters to define general acquisition parameters The dialog box shown below appears on screen The following parameters may be defined Name m omes a Input a measurement identifier This identifier appears in the field P 3 i j arameters Location of the measurement session Rectangular s7 Overlap 50 r Cancel Pass band Hz Physical characteristics E FFT Wi ndow Min so Microphone spacing 12 nn Choose the FFT window for the analysis The following windows Fax 5 k seria sand 343 370 mis are available Rectangular Hanning Hamming Kaiser Bessel and Flat Top e Full octaves censal zos 205 kon p Peace oc ae Fac O pc V Adjust to physical frequency limits Overlap option Choose the overlap factor for the analysis amongst the following M eree correction M Automatic autorange quantities 0 25 50 and 75 W Convolution correction I Warning message if parameters are adjusted Storage mode These factors depend on the hardware platform possibilities and the chosen bandwidth Autospectra cross spectra and Intensity Customized GC Displayed results a a Pass band Hz Define the upper and lower limits of the analysis pass band These values are the third octave frequency bands The pass
116. e below to define a generic remote control object Selection of the remote control Configuration of the remote control Assignment of the input functions Assignment of the output functions Configuration of event triggering parameters in the application software if required Use of the remote control QL IN PAGE 168 DBFA SUITE USER MANUAL 10 1 1 Selection of a generic remote control Hardware configuration x Configuration file New Open Save as Name O V4PPLIGB 4s het Hardware peripheral Remote control Remote control selection generic 2 inputs 2 outputs Configuration Remote control selection Available remote controls igenenc 2 inputs lt outputs 6 R 4 5 automatic calibration G A 5 5 intensity probe Cancel 10 1 2 Configuration of a generic remote control gb_dBFA NUT 043 A At the hardware configuration stage select the remote control tab shown only if the DBCD32 INI file is present in the 01dB Metravib programs directory The dialog box shown aside is displayed on screen Click on the gt gt key and select the remote control type generic 2 inputs 2 outputs and click on OK The specific remote control G R A S automatic calibration and G R A S intensity probe are predefined object to respectively activate the electrostatic actuator of the GRAS outdoor microphone units 41AM and 41CM automatically from the application software dBTRIG32 and
117. e computer hard disk click on the icon or use the command File Open The following dialog box appears on screen Open Look in E data Select a measurement session file in the list SCE CIEMEINETABCIE test_991116_094450 CMG files with CMG fa demo_981118_103444 CMG se test_991116_094749 CMG Selection of the hard extension a fast_981113_160439 CMG test_981116_094954 CMG disk sub directory a test 981116 094019 CMG a test_991116_095039 CMG where the CMG files laa test_981115_094055 CMG are stored la test_987116_094145 CMG Name of the selected measurement File name demo_981117_181137 CMG Open session file A Files of type o dB Measurement File CMG Ea Informati a rent a lv Details Detailed information on l General Size bytes 518199 the selected CMG files information on Start 17 11 98 18 11 37 number of audio the selected CMG End 17 11 98 18 33 28 records noise file Autospectr quantities codes etc Created 19 11 98 13 55 33 Saved 19 11 98 13 55 32 Version 1 001 tems g Audio Leq Range The upper part of this dialog box allows the user to select a measurement session file CMG for processing in dBFA by choosing the appropriate location on the hard disk The lower part of this dialog box is activated when a CMG file has been selected in the list Various information on the datafile is given such as E The date and time the file has been first recorded and when
118. e digital inputs outputs of the acquisition unit with the interface box G F A S intensity probe remote control set up Meme GRAS intensity probel r Communication Define the duration parameters Blinking and Flash corresponding to the two output states and Long push corresponding to one of the two input contacts according to your specific needs C Serial Symphonie kort None 7 Duration parameters ms act foo 15 The functions assignments of the inputs and the outputs of Flash or K this remote control cannot be modified Refer to the example described in paragraph Erreur Source du renvoi introuvable for a detailed description of these functions to remotely control the measurement process during real time acquisition in dBFA Long push fi 000 Double lich inputs Wotputs Cancel 10 4 1 2 Connection and operating process Once the remote control is configured switch on the measurement system and connect the probe to the acquisition unit with the interface box channel 1 channel 2 and digital inputs outputs Start a real time acquisition in the intensity mode or ISO9614 mode Then proceed as follows O Place the sound intensity probe at the first measurement location When the Green LED blinks it means that the system is waiting to start an acquisition O Press the Blue button The acquisition starts At the end of the acquisition
119. e display dynamic range Annuler Appliquer Appliquer 4 tous Fixer par d faut Refer to paragraphs 11 3 and 11 4 for a detailed list of the frequency weightings and spectral units available in dBFA Overall levels tab broad band spectra and multispectra Display parameters setup x Frequencies Data Overall levels Graphics In this tab and for broad band spectra and multispectra only select the overall levels to compute according to a given frequency T Lin overall level between cursors weighting displayed in a list J Use Overall levels are then displayed on the right handside of the Mex 2000 00 H spectrum view If two cursors are activated it s possible to calculate a Lin overall level between cursors noted Ec on the graph wh gt Annuler Appliquer Appliquer 4 tous Fixer par d faut Overall levels are then displayed on the right hand side of the spectrum view Refer to paragraphs 11 3 for a detailed list of the frequency weightings available in dBFA Graphics tab Display parameters setup 5 x Frequencies Data Overall levels Graphics In this tab select the type of graphics that will be displayed line Bars mode or bar mode C Line Stair mode Line Mountain mode Examples of the different types of graphical representation are given below Annuler Appliquer Appliquer 4 tous Fixer par d faut Bar mode Line mode stairs Line mode mo
120. e every 500 ms and the state Flash generates a voltage on this pin for 1000 ms only one time The configuration of the input and output functions can be accessed by the keys Inputs and Outputs PAGE 169 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 1 3 Assignment of input functions After configuration of the general parameters of the remote control define which input function will be assigned to each input contact Access the dialog box shown below by the Inputs key Select for each state of an input contact a function in the list of input functions The input contacts present three different states Inputs assignments Es Contact 1 Click Start function 1 hu Double click Star function 2 a Long push Not used Contact 2 Click Stop function 1 a Double click Star function 2 a Start function 2 Long push Stop function 2 Start function d Stop function 3 Start function 4 Stop function 4 Click Simple push of a key The voltage on the appropriate pin of the connector of the communication interface passes from OV to 9V RS232 or 5V SYMPHONIE HARMONIE while the key is pushed Double click Two successive pushes of a key The voltage on the appropriate pin of the connector of the communication interface passes from OV to 9V RS232 or 5V SYMPHONIE HARMONIE twice over a user defined time interval Long push Continuous push of a key The voltage on the appropriate pin of the connector of t
121. e the rectangle to be enlarged with the mouse pointer by keeping the button pressed 3 3 4 6 Sonagram preferences The menu Preferences Sonagram is used to access the additional settings concerning the sonagram display Sonagram o The size of the section display in relation to the sonagram view is defined in percentage o The user can also define horizontal or vertical display of the time axis Frequency axis Horizontal Section proportion window Horizontal section ai Z T Vertical ertica Vertical section fao EA Cancel Validate the modifications by OK The changes are taken into account directly on the open windows of the sonagram 3 3 5 Nichols Nyquist views This type of view is used to display all narrow band transfer functions and cross spectra with or without timing To view the Nichols or the Nyquist diagram select the item and go to Sessions Nichols Nyquist PAGE 43 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The figure below shows an example of Nichols Nyquist view Definition of parameters for display and cursor synchronisation ES plaque_pri CMG 2 ame 1D 7 Average H1 1 2 gt 1 MENE EZ ZEN ME iz Hz dB Degrees ENN MSIE EEEE Display of modulus or real part for the complex number See eee ee ete Seer LEE Leet eee iy Perret Nichols or Nyquist display A A A A CeCe et A See eee te ARA E E AAA Cort pet AA OSS eer A Se AA 400 5000
122. e to RPM profile conversion RPMTACH This operator is used to convert a tachometric signal acquired on a dynamic channel into a speed profile used for order analysis The dialog box shown below is displayed on screen RPMTACH_0 pulse to rpm profile conversio 1 x In the Configuration tab the following analysis parameters may be defined Operator Setup detection level Volt ss O50 E Detection threshold Define the threshold value for pulse Nb top per rev 1 00 detection Hold Off delay 80 0 EEE EM Lower threshold Hysteresis Define the lower threshold before reactivating the trigger for the pulse detection case when the Slope det Positiv Negativ tachometric signal is of poor quality Number of pulse per revolution Specify the number of pulse per revolution Save the result Annuler Hold Off delay Define the time period during which the trigger is deactivated as a percent of the time between the two previous triggers case when the tachometric signal is of poor quality Averaging Define the number of items to average before calculating the speed Slope definition Define the signal slope for pulse detection Example poor quality signal V Detected pulses Triggering threshold Lower threshold Hysteresis FI Hold Off in The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operato
123. e user to reduce the frequency range of analysis around a centre frequency and thereby increase the frequency resolution Select Zoom in order to activate the FFT zoom option Then choose the centre frequency and the zoom factor The curve on the left hand side informs the user about the chosen parameters The red information bar lower part indicates the analysis frequency range while the spectrum the chosen frequency resolution To modify the centre frequency or the minimum frequency when the Zoom option is activated of analysis move the cursors respectively to the right and to the left The user can also modify the zoom parameters by setting the zoom factor and the centre frequency in the right part of the dialogue box Multispectra if this option is activated the user obtains the time history of the spectrum over the item duration The time step may vary from 1 ms to 999 ms The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Dual signal analysis Default name FBG120 Activefor 2 items of the Signal famil Apply for 2 audio events with same sampling frequency The length of a time block must smaller than that of the signal Restrictions Family of the result PAGE 75 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 1 4 Broad band spectrum Operator FC This analysis results in a broad band spectrum ranging from octav
124. eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeseeeeeeeeees 91 4 6 2 19 Integration Derivation operator DIN cooccccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnniness 92 TABLE OF CONTENTS PAGE 6 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A AG 2 20 Statistics opera or A e lees 93 A622 Sidine statistics operator gt AMES aaa 93 AGi222 se Axcis Operator AA ed a al do elo a 94 AO ODER ONS OW SPOT E AR a is 95 4 6 3 1 A A O E 95 4 6 3 2 Frequency recomposition Operator I RECOMP E Dos 96 4 6 3 3 Time recomposition Operator RECOMPT Joooocnnnnnnnnnninininininnnnnnnnnnnnnnnnn nn nn rn 97 4 6 3 4 Intesration Denvation Operator PBID lean AE nieta sacd 98 AO Argen Tesponse JUNCOS iia 99 4 6 4 1 TEON xi ees E E E ta Ae atl ed eae te eau 99 4 6 4 2 Cross Spectrum G2 Operator EB OZ aah ca Sat Be li 102 4 6 4 3 Frequency response function H1 Operator FBH oococcccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninnnnnoss 102 4 6 4 4 Inverse frequency response function 1 H1 Operator FBIH ooooonnnnnnnnnnnnnnnnnnnnnnannnananannnnnnnnnnnnnnnnnnnnnnno 102 4 6 4 5 Frequency response cross function H2 Operator FBHA2 oocccccccncnnnonononnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnos 103 4 6 4 6 Inverse frequency response cross function 1 H2 Operator FBIH2 oooonnnnnnininonininononinnnnnnnnnnnnnnnnnnnnnnnnnnnannnno 103 4 6 4 7 Coherence Operator EBCOR
125. efine analysis parameters if required e g Number of lines and frequency range for a narrow band FFT analysis The name and a description of each operator as well as notification of the computation progress are also available A script regroups several operators assembled in series or in parallel One can therefore build up a complex analysis script from these simple layers The script structure also help to check that the analysis is coherent compatibility of the output items of one stage and the input items of another stage and to activate each operator when all entities inputs analysis parameters are available to run the processing function In the actual version the operators cannot be assembled in series A script therefore regroups operators in parallel acting independently from one another to process the same input data items SCRIPT OPERATOR 1 RESULTING ITEM 1 ITEM 1 o OPERATOR 2 RESULTING ITEM 2 ITEM 2 OPERATOR i RESULTING ITEM i All the scripts available in 01dB Metravib application software are themselves regrouped into a calculation server with a user interface to configure and run an off line analysis dBFA proposes a set of pre defined scripts managed by the calculation server It allows the user to activate configure stop and suspend an off line analysis PAGE 61 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 2 Calculation server overview When a measurement session datafile is opened u
126. ems We therefore decided to call this type of file measurement session A measurement session is therefore defined by its name generic root name a comment to fully describe the context of a measurement But what do we found in a measurement session file and how do we handle the data Going down one level in the structure we reach the heart of the data file structure that is the elementary entity used to store a given type of data This generic entity is called an ITEM Its structure is identical for all quantities stored in a measurement session Physical data storage of the items is not shown to the user Depending on the requirements of the application software used the measurement sessions which reference in its header all these item boxes will contain the complete set of measured quantities in a single file or in individual files one by item In both cases later computing operations file copies architecture on the computer hard disk etc will be easier to integrate and to perform O Item Let us now describe this structure the item is a stand alone quantity that must be able to contain any type of data sets description metrological and reference information actual measurement values in order to address the present and future measurement applications A non exhaustive list of items currently stored as items is given below PAGE 183 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The following quantities measured b
127. enough to obtain at least 5 lines per broad band Family of the result Autospectrum PAGE 76 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 1 5 Pseudo Wigner Ville transform operator Use this operator to obtain a multispectrum with a timing ranging up to the sample and a good frequency resolution The Time Frequency ratio can reach 1 41 The dialog box below is displayed on screen In the Configuration tab the following analysis parameters may be defined WYI_0 Pseudo smoothed Wigner Yille q x Operator Setup Time step Define the timing for multispectra in milliseconds or sample by sample by checking the Point by point option Time Toe e po a depends on the sampling frequency Analysis window Analysis window Define the number of points in the time att E Window Hanning window under analysis which corresponds to 2N 1 an odd number and then select the weighting window to apply to the smoothing window calculation The sample seeing back the spectrum instant is Foints number a Windows Hanning the centre sample Smoothing window Define the number of points in the time smoothing window corresponds to 2M 1 an odd number then select the weighting window to apply to the smoothing ei Save the result Annuler The Operator tab provides a detailed description of this type of processing and offers the possibility to change its name Default script Signal analysis Default name WVI
128. ent channel the order extraction with method choice constant resolution in order or in frequency The extraction is performed by successive levels for stabilized values of the speed In the Setup tab the following analysis parameters may be defined EOP_MULT_0 Extraction d ordres par paliers succe EQ e Tracked orders Add orders to extract Orders can be non integer Operator Configuration N Tracked orders e Tracking parameters Define the speed interval between two FFT spectra calculation Input minimum and maximum speed of the analysis Edit Delete Tracking parameters rpm Min 500 Stabilization fi gt Max e000 Min duration fi s e Strategy Indicate if it is a slowdown decreasing or a revving up increasing e Synchro Define how to synchronize the results with the rpm values beggining middle or end Recomposition method Define recomposition width Expressed in frequency if recomposition in Delta F or in order if recomposition in Delta N Strategy Increasing Y Synchro bloc Middle z Recomposition method C Constant Df Constant Dn fi 0 OK Annuler In DeltaF the minimum width of recomposition is given by the Frequency resolution In DeltaN the minimum width is given by Frequency resolution RpmMin 60 RomMin being defined in the parameters of the tachometric channel The Operator tab gives an overview of this type of p
129. ent frequency modulation can be generated on each channel White noise Pink noise Sine LF way file Identical channels Channel No If at least 2 channels are used different signals can be generated on each channel Select the channel to configure if you wish to configure each channel independently Channel Identical channels i Modulation duration ms sono LFM channel parameters 1 Low frequency Hz 50 Gain dB o High frequency Hz 500 Modulation time Enter the sweep time in ms MLF parameters Enter the lower and the upper frequency as well as the gain and the sweeping direction l for the modulation f Increasing freg sweep C Decreasing freg sweep Once signal parameters are set use 4 to launch the emission 11 8 6 Generating a WAV file To generate a signal resulting from a WAV file click on the WAV file tab white noise Fink noise Sine LFI a file Click on WAV file selection and open the file Selection of Wey file PT esures Son Way Once signal parameters are set use to launch the emission PAGE 189
130. eo 181 UEA SPECTRA UNIS DISPLAY TYPE aa 182 11 5 STRUCTURE OF MEASUREMENT SESSION DATA FILES CMG cooooocnnccccccnnnnnnnnnnnnnnnnnonononocccnnnnnnnnnnnnnnnnnnnos 183 11 6 CONVERSION UNITS AND REFERENCES MANAGEMENT FROM A PHYSICAL UNIT TO A DB LEVEL 185 Mids EDING OFTHE SOFTWARE LICENCE NUMBER eusicliilllados 186 S GENERATING SIGNALS WIPE DB GEN Eccica ere cal is 187 11 8 1 Prosena on opa BGENE holaaa a a an e lol etd lala don aes 187 11 8 2 Cn ranno ANS AIR A aia aa A a 188 11 8 3 IA DINK NOS Cx 2 rete II II dated tee Oates 188 11 8 4 Genera In MEMOS Cd AS carted Dats stasis Os iia Add 188 11 8 5 Generating regueney Modula liOn arere 189 11 8 6 Conran MA MM A A A A il ai eat ee 189 TABLE OF CONTENTS PAGE 8 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 1 DESCRIPTION OF A 01DB METRAVIB PC BASED MEASUREMENT CHAIN You have purchased a 01dB Metravib PC based system to perform sound and vibration analysis The 01dB Metravib concept is to combine sound and vibration instrumentation with the computational and management facilities of a PC For first time users of a PC based measurement chain the following chapter describes the concept with respect to environmental noise measurements For more general information on the concept of a PC based measurement system see the getting started user manual delivered with your system 1 1 Introduction In recent years there has been much written and said about the use
131. equency limit During an FFT analysis we obtain a spectrum with lines uniformly spread over the frequency axis with a resolution of fs N where fs is the sampling frequency and N the size of the FFT used number of samples However the lower the centre frequency of an octave band or 1 n octave band the smaller the bandwidth We therefore have only a few narrow bands to recombine a broad band at low frequencies and we often go under the limit of 5 lines for a statistically correct synthesis Another drawback of the method can thereby be identified high frequency broad bands are the synthesis of a large number of narrow bands while it is not the case at lower frequencies _ Time resolution compromise One can obtain a result for a given band only if the number of available points for computation depending on the undersampling stage and the original time duration of the signal is greater or equal to the FFT size required to synthesise this band The number of points can be greater than the number of points required to obtain the time resolution required The result cannot therefore be obtained for the time step but for a greater one Digital filtering This method is based on a bench of digital filters as many filters per octave band as there are octave sub divisions of the Butterworth family of order 8 These filters consist of a chain of 4 elementary Butterworth cells of order 2 Advantages of the method LJ Accurate estimation of the r
132. er may use this configuration again for other measurement sessions with the same parameters command Acquisition Open a measurement set up The real time measurement window appears after setting up all parameters Each function is now accessible from the measurement window toolbars PAGE 143 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 1 Measurement window overview An example of a real time intensity mode measurement window is given below Display parameter toolbar curves to display overall levels spectrum units etc iM RealFc3 lO x G1118 Hz dB Ref 2 000e 05 Pa RMS G2218 Hz dB Ref 2 000e 05 Pa RMS Command bar 100 acquisition parameters eo eee AENA averaging gains Display of measurement E acquired data with E 63 1235 250 500 dk 2k 4k 4E a AE ak 50 IA DT 459 100 start stop etc cursor values 315 63 125 250 500 ik 2k 4k 8k 16k A Lint o e roger Manuel Status bar status and information on the measurement progress The measurement configuration and control is accessible via the vertical command toolbar In the following we describe the functions of each icon i Enable disable cross function computation Stop the acquisition Define acquisition parameters Continue the acquisition gt m Define averaging mode and attributes Validate current results MA q Internal signal generator option Cancel current results and start again k
133. er par d faut Select a Lin scale or a Log scale for the frequency representation PAGE 33 DBFA SUITE USER MANUAL Data tab Display parameters setup i l Frequency Data Graphics Modulus Polar Complex Spectral units V Optimize Pwa y PWA Dynamic dB e Min 20 Max soo Dynamic Degrees Degrees Y Fixer par d faut Annuler Appliquer Appliquer 4 tous spectral data values gb_dBFA NUT 043 A In this tab select if the data should be displayed in physical units Dynamic Lin or Log or in decibels dB Then select the required spectral unit RMS PWR PSD ASD or ESD for narrow band spectra and RMS PWR PSD or ASD for multispectra as well as frequency weighting to apply to the If the Optimise box is not ticked the user may then select the minimum and maximum values of the display dynamic range For cross spectra and transfer functions the user may display the data values in different manners just the modulus absolute value of the considered quantity in polar form modulus and phase or in complex form real and imaginary parts When displaying spectra in polar form the phase can be represented as unfolded to have a clearer representation when the phase oscillates between 180 and 180 To do so select a dynamic range in Degree or Radian Different examples of these types of views are given below LJ Graphe spectre BE
134. ers Window size Enter the duration of the indicator Window size calculation window Overlapping Overlap Enter the overlap factor for the calculation Indicators I Minimum W AMS deviation I Maximum 4 Standard deviation Mw Average EAS lit The Operator tab gives an overview of this type of processing M AMS average e Skew asymmetry function and allows the user to modify the default name of the W AMS sum e Kurtosis flattening operator Indicators Check the elements to calculate W Variance Saye the result Armuler Default script Sliding statistics Default name STATGLISS_0 EEE Activefor Sig Applies to 1 item Result family Signal 1 item per index PAGE 93 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 22 y Ax B Operator AXB This operator performs y Ax B affine transform It is used after an integration to add an offset The Setup tab allows to define A and B values After an integration choose A 1 and B offset The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal Analysis Default name AXB_0 Applies to 1 item PAGE 94 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 3 Operations on spectra 4 6 3 1 Theory Various operations are possible on spectra Frequency recombination From spectra or multispectra in narrow bands or in broad bands it is possible to recom
135. es to 1 48th octaves with time history capability broad band multispectrum The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined il deca Bandwidth to define the spectrum bandwidth for the analysis 1 1 1 3 1 6 1 12 1 24 and 1 48th octave bands Operator Configuration Notification Frequencies Bandwidth Min Hz Max Hz Min Minimum centre frequency of analysis in Hz 1 24 octave 16 Ek r gull actlayez Max Maximum centre frequency of analysis in Hz 7 Multispectra Analysis pb efs m Full octaves If this option is activated the software will set the minimum and maximum frequency limits so that only full octaves are calculated Analysis Select the method used to perform frequency analysis FFT or digital filtering I Save the result Annuler Multispectra if this option is activated the user obtains the time history of the spectrum over the item duration The time step may vary from 1 ms to 999 ms The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name FCO CC CSCi s CTS Activefor Signal Impulse Response families Only apply for one item The time resolution required for multispectrum must be less than Restrictions the item duration FFT synthesis the item must be long
136. essing exports the input data in MPEG Layer III MP3 MP301DB_0 format The exported signal must be sampled at 32 or 44 1 kHz Overall Loudness level time history BGLOBAL_0 This analysis results in the overall Loudness level time history of a Bark Loudness Bark multispectrum spectrum OPERATIONS ON PARTIAL LOUDNESS PAGE 69 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 Overview and configuration of operators processing functions An operator is used to perform an analysis on a single or several data items Each operator has its own name that the user can modify analysis parameters and computation progress information When an operator process a data item this input quantity is locked in the active document It cannot be deleted and the document that controls the calculation server cannot be closed These items are unlocked when the calculation is ended or aborted The following paragraphs present each operator definition set up parameters compatibility etc The operators are presented as follows Spectral analysis Theory narrow band and broad band spectra and multispectra narrow band cross spectra pseudo Wigner Ville transform decomposition in Morlet wavelets Capon transform autoregressive modelling on a sliding window Operations on Signal data Theory low pass high pass band cut band pass notch filtering undersampling A B and C frequency weightings user defined time windows gain optimis
137. esult L Time resolution very small No limitation or time frequency compromise Drawbacks of the method LJ Digital filtering requires a delay to be performed because of the delay of energy propagation induced by the physical characteristics of the filter depending on its complexity and type A delay therefore appears at low frequencies because of the large number of filters used PAGE 72 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Time Frequency analysis Spectral analysis based on Fourier transform FFT and digital filtering 1 n octave provides a good description of stationary and pseudo stationary signals Unfortunately there are limits to these techniques when signals to analyse are not stationary In this case the solution is to calculate instantaneous spectra for each time step of the signal Tools to do so are called time frequency analysis techniques There are several methods none of which is predominant Their use depends on the target application and on the pros and cons of each one to display requested information Several methods can be used by dBFA Wigner Ville transform WVT Wavelets transform WT Autoregressive modelling Capon transform The increase in computer resources has allowed for the application of digital models of these transforms and thus obtain the time frequency descriptions of these non stationary signals However even before the computer era man and especially the musician has used time fre
138. esult family Autospectrum 4 6 1 7 Autoregressive modelling operator Use this operator to obtain a multispectrum with a timing down to the sample and a good frequency resolution The Time Frequency ratio can reach 1 41 The dialog box below is displayed on screen In the Configuration tab the following analysis parameters may be defined Mi x Operator Setup Number of lines Enter the number of lines that will define the frequency resolution Lines number 401 es io Order Define the filtering order a high order can yield better results Sliding window 20 me Time Sliding window Define the length of the time block to Time step jo 3 f ms Point to point analyse Time Define the timing for the multispectra in milliseconds or sample by sample by checking the Point by point option depends on the sampling frequency Save the result Annuler The Operator tab provides a detailed description of this type of processing and offers the possibility to modify its name Default script Default name FARO Activefor Signal family Applies for one item onl Result family Autospectrum PAGE 78 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 1 8 Capon transform operator Use this operator to obtain a multispectrum with a timing going down to the sample and a good frequency resolution The Time Frequency ratio can reach 1 41 The dialog box below is displayed on screen In the Configuration tab
139. example is shown below Definition of parameters for display and cursor synchronisation faa Test Lissajou 2 CMG 2 zz Me xj la exme 10 8 Voie 0 sv TENN NENE Signal display for both channels Lissajous display 0 5 AAA AAA A 0 683914 The toolbar in the graphic window is used to perform the following operations Cancel zoom Zoom function is accessible by i Define Edit data parameters for display eq pressing on the Shift key and selecting the area with the mouse Pil Place cross cursors in corners Cursor synchronisation for the selection of a specific working area PAGE 45 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Levels in dB are calculated with respect to the international system reference values Reference values can be modified as well as the physical units using the Preferences Units management menu See Section 11 1 3 4 Listings of data items tables Use the command Datafile List after selection of one or more data items in the list in order to display data items as a table of results The user can also double click on the items of interest to display the table of results The following types of data items may be displayed as a table in the application dBFA Broad band spectra Stationary psychoacoustic criteria Examples of tables of results are given below A psy cmg Listing E D 01d801dB programs 32bitidatabinipsy cmy 26 Autospectrum Leq Date 22 07 97 0
140. ezden ells A study zone over the complete duration of Ei eaae A f Show Hide a channel and activate deactivate a channel for any subsequent study The vertical toolbar allows the user to define the study zone for the signal and to perform threshold search operations Threshold search The threshold search command command Study Threshold Search allows the user to define the level of the threshold value Level Pal Slope given in physical unit and a slope positive or negative to the Min Mar W threshold condition 5 068e 01 0 000e 00 4 7268 01 E When the threshold condition has been fulfilled the cursor is located at cora the threshold exceeding on the graphical view The command Ed allows the user to stop the threshold search and the command allows the user to find the next threshold exceeding PAGE 27 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The horizontal toolbar allows the user to define display parameters of the graphical view It is possible to use zoom functions to zoom a part of the signal and perform an autoscale for the zoom view The display units depend of the type of graphical view For signals it is possible to select the following display units DAC Displays the dynamic in dB converter It is a relative decibel level The OdB level is the full scale value of the converters i e a sample which has a numerical value of 2 16 32767 corresponds to the OdB value dBDAC values are a
141. f measured data into an input voltage and the reverse process after data analysis to display the results A transducer must be prescribed to each active channel Calibrator The calibrator configuration allows the user to perform the calibration routine which adjusts the transfer function of the transducer in order to perform calibrated measurements A calibrator must be declared for each active channel except for measurement channels with a voltage type transducer 6 To enable direct power supply of a transducer from a HARMONIE or SYMPHONIE unit define the same option s for the transducer s and for the hardware platform Configuration command in the dBCONFIG tool LL For more information concerning hardware configuration refer to the getting started manual delivered with your measurement system PAGE 139 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Remote control tab The dialogue box shown below allows the user to configure the parameters of the dialogue between a remote control object and the measurement software to perform a specific operation ex threshold trigger of an visual alarm remote control by push button for audio triggering remote control for the measurement control from the holder of an intensity probe Several remote controls are available For more information concerning its configuration and use refer to the chapter Remote controls E Phase correction tab Select this option in order to activate the ph
142. g A recording progress indicator appears in the status bar of the real time window giving a percentage of the total recording progress cancel 329 PO El Show hide the overload bar The overload dialogue box appears on screen when this command is activated This dialogue box enables detection an overload at any time Overload There are two indicators for each channel one for the instantaneous overload another one for memorisation of the overload The button Reset allows to reset the indicators The instantaneous overload indicator becomes red as soon as an overload occurs on a given channel and becomes green again when it is terminated The indicator which memorises the overload becomes red as soon as an overload occurs and stays red until the button Reset is pressed PAGE 157 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 9 ORDER EXTRACTION Order analysis is based on the frequency analysis of a system s sound or vibration emission which is related to its rotation speed and the harmonics of the rotating parts orders This measurement method mainly applies to rotating machinery with fixed or variable speed One can thus observe effects generated by rotating elements and their amplifications due to structural resonances During an order analysis one or several sound or vibration measurement channel and one tachometric signal are recorded simultaneously With dBFA order extraction can be carried out from a FFT freque
143. g requests data sorting Measurement session datafiles have a structure similar to databases As any measurement result is stored into these datafiles a set of requests functions allow the user to sort the data according to various parameters One can display for example data items of the same family only audio events narrow band spectra octaves and third octave spectra etc in the measurement session view 3 6 1 Overview of requests editing Use the command Datafile Edition of requests to open the dialog box that allows the user to define edit or remove requests Management of requests 3 List of requests general audio Channel 2 30s to 1 mir Add i All items date type A DCA TEQquezt AND tems Audio Add global request OF Cancel dBFA manages two types of requests local requests which apply only to the active measurement session and global requests which apply to any measurement session Global requests are preceded by an asterisk The procedure to define a request is the same in both cases Click on Add local request to add a new local request to the active measurement session and click on Add global request to add a new global request for any measurement session that will be opened in the application software Click on Edit to modify an existing request selected in the list and click on Remove to remove an existing request from the list By defaul
144. gration derivation of the input and or output spectrum according to the physical unit of the input and output function an autospectrum or a cross spectrum for each case The possible selections for each type are summarised below DERIVATION Jerk m s Acceleration m s Velocity m s Displacement m INTEGRATION PAGE 156 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 4 Measurement process After measurement configuration the user can control the measurement process with the following icons t Start an acquisition F3 The acquisition starts according to the defined acquisition and averaging parameters When a trigger condition is defined with the command Gain and threshold the analyser waits for the trigger event in order to start the measurement Stop an acquisition F4 m BE E EE Continue a stopped measurement F5 This function continues averaging the previous results with measured values Valid current results F7 The measurement results are saved in a measurement session datafile Do not accept current results and restart the measurement F6 Start a signal recording F12 Start a signal recording directly from the real time measurement window The audio record will be carried out according to the user defined duration the other parameters gains frequency range etc are identical to the current real time analysis parameters Spectrum measurement is deactivated during signal recordin
145. he communication interface passes from OV to 9V RS232 or 5V SYMPHONIE HARMONIE twice over a user defined period When one of these states occurs an input message will be interpreted by the application software The table below shows a list of the actions that will interpreted by dBFA for each input function FUNCTION STATE ACTION MEASUREMENT STORAGE Start or accept a measurement data logging Stop function 1 Stop or reject a measurement data logging PAGE 170 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 1 4 Assignment of output functions After configuration of the general parameters of the remote control and the input contact assignments define the assignment of the output contacts that the application software will send to the physical remote control when a user defined condition has been fulfilled for example activation of a LED when a measurement result has to be validated Access this dialog box by the Outputs key For adequate output functions or events define the state of each output contact Output contacts present four different states Outputs assignments eel No use Active While an event is activated the voltage on the appropriate pin of the connector of the communication eater interface passes from the current state to 9V RS232 or 5V Active SYMPHONIE HARMONIE eile ee Inactive While an event is activated the voltage on Inactive the appropriate pin of the connect
146. his file describes the maximum number of colours that are available for the display of the sonogram and gives an exact colour for certain levels The colours are defined with the RGB code red greed blue expressed in decimal numbers Example of a User rgb file NB_MAX_COLOR 64 64 colours palette 0 255 0 0 75 0 0 255 75 Interpolation of 64 colours between red and blue 100 0 255 0 25 Interpolation of 64 colours between blue and green RED BLUE GREEN A 10 Sl 100 64 colors 3 3 4 4 Data calculation parameters for display Use or Sonagram Parameters to set calculation parameters A dialog box including several tabs is displayed on screen These tabs are used to define the parameters described hereafter TT Fised by default To set the default parameters check the box and click on OK Apply or Apply to all PAGE 41 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Frequencies tab Display parameters setup x Frequency Data m Frequencies Hz Min ooo ki H Max Y H Iv Al Select the minimum and maximum frequency bands to be displayed on the graphic view Check the All box to view data over the acquisition frequency range Lin Annuler Appliquer Appliquer tous Fixer par d faut Select a Lin scale or a Log scale for the frequency representation Data tab Display parameters setup x Frequency Data Select physical u
147. ible to select the following display units dB Level in decibels of the considered quantity Leg Slow Fast Impulse etc RMS Root Mean Square Average quadrature value for all the instantaneous squared values expressed in physical units PWR Power The power represents the average of a squared value It is the unit used to determine the power at a given frequency for a determined sinusoidal signal It is expressed in squared units PSD Power Spectral Density This unit is used to determine the power in a frequency band for a random signal It is expressed squared units by Hertz ASD Amplitude Spectral Density This unit represents the square root of the power spectrum density It is the unit used to find the amplitude in a frequency band for a random signal It is expressed in square rooted units per Hertz ESD Unit representing the power spectral density multiplied by time and expressed Unit x second Hz PAGE 182 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 5 Structure of measurement session data files CMG This chapter describes the structure of the datafiles as well as all the resulting processing operations O Measurement session The first requirement in the definition of this format was to identify a structure of the container type intuitive enough for being used by an non experienced operator and flexible enough to store all type of noise vibration and other quantities measured by 01dB Metravib syst
148. ical unit of the Y axis quantity 1 n octave Results generated from building calculations airborne isolation shock noise Building calculation Set of data items of the same family signal autospectra transfer functions etc Peak Fast Fast Inst Fast Max Fast Min Impulse Impuls Inst Impuls Max Impuls Min instantaneous Isel Leq Min RC RC Inst RC Max RC Min SEL Slow Slow Inst Slow Min Slow Max Tmax 3 Tmax 5 For cross spectra Y1 corresponds to Acceleration counter displacement force jerk Noy the physical unit of the first item and pressure rate rate DC second scalar sone D F Y2 axis Y2 corresponds to the physical unit GD GF voltage velocity W m2 quantity of the second item used to calculate the cross spectrum Identifier of the data item A number This number is incremented from 0 each time a data item is added to the measurement session Information on some calculation Manual input results order analysis Location defined during acquisition Channel 1 by default For cross Location spectra it corresponds to the Manual input of a location location of the first measurement channel Manual input of a number PAGE 52 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Fields Description Op column Fields column column Name of the analysis that created this data item It is the name of the operator for an off line analysis and Manual input the name of
149. ich specific weighting will be applied This operation is really important for later definition of the sections of the weighting window Access the Windowing operator and define the adequate segments for the signal s under investigation Click on the Add button to add a new section on the Edit button to modify an existing section and click on the Remove button to delete an existing section of the window Click on the Delays button to define delays before and after the window if necessary Click on the Save button to save the weighting window in the application software This window can be recalled later next time the user wishes to analyse data items with the same window Close the configuration dialog box and run the analysis script see paragraph 4 2 The beginning of the time window excepted the pre delay will match the beginning of the signal study zone PAGE 86 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Add and Edit keys Click on the Add button to add a new section or on the Edit button to modify an existing section of the weighting window The following dialog box appears on screen Select the section duration in milliseconds as well as the type of classical window to use Rectangular Hanning Hamming Blackman Harris Kaiser Bessel FlatTop Triangular Exponential Zeros and Holes Then select if only the rising slope the falling slope 1 or the complete window will be part of the section Once the section
150. indow effect and the position of the significant harmonic PAGE 37 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A If no harmonic meets the emergence and proximity criteria one can force a harmonic by double clicking on the cursor of the chosen harmonic The interpolation calculation can then be launched based on the selected harmonic Search parameters set up Use Preferences Multiple Cursors to set parameters for harmonic search The dialog box below is then displayed Parameters pertaining to harmonic and sideband cursors are circled Multiple cursors Preferences X Cursors Cursors Enter the number of cursors to calculate and display Number of harmonic cursors E The number of sideband cursors is always odd given that we Nambenarer cocine band pa are searching for frequencies side bands around a centre frequency carrier Humber of cursors of maxima 20 I sorted by levels a Marking criteria The Most significant harmonic parameter is used to set the tolerance between the position of the most significant harmonic and a maximum Criteria of marking Precision of marking Most significant harmonic 100 se dF Precision of the displacement of the cursors 1 d The Precision for cursor displacement parameter is used to define the displacement step for the cursor placed on Emergence criterion the fundamental frequency Minimum emergence z dE Number of symmetrical bards for
151. interpolation calculation depending on the FFT weighting window and on the peak shape since the exact value is never located exactly on a FFT calculation line Search parameters set up Use Preferences Multiple Cursors to set parameters for maximum search The dialog box below is then displayed Parameters pertaining to maximum cursors are circled Multiple cursors Preferences q x Cursors Number of harmonic cursors z Number of cursors edge bands 11 Humber of cursors of maxima 20 gt M sorted by levels E Criteria of marking Precision of marking Most significant harmonic 100 dF Precision of the displacement of the cursors Z dF Emergence criterion Minimum emergence F dE Number of symmetrical bards for A calculation to emergence E E bands Cancel Cursors Enter the number of cursors to search for and display For maximum cursors they may be sorted by level if the box Sort by level is checked If this box is not checked maxima will be sorted by increasing frequency Emergence criterion Set criteria for maximum detection Enter the minimum emergence with respect to the level of the two symmetrical neighbouring lines located X 2 lines on the left and X 2 lines on the right for a peak to be considered as a maximum X being the Number of symmetrical neighbouring lines Example If the Number of symmetrical neighbouring lines
152. ion Carry out the calibration of the measurement chain before each measurement Command Acquisition Calibration Refer to chapter 7 L Stage 4 Choice of the type of measurement Open a new measurement set up Command Acquisition New measurement set up or open an existing one Command Acquisition Open measurement set up to perform a real time acquisition The user may choose to perform the following types of real time acquisition Sound intensity INT Intensimetry Mode file See Chapter 8 Sound power 1S09614 File New IS09614 campaign command Measurement configuration contains all the parameters associated with a measurement PAGE 13 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 3 Data processing with dBFA Data processing in dBFA can now be performed in a global manner thanks to the implementation of analysis scripts Each processing operation is available as an operator which assembled in series or in parallel composes an analysis script The scripts available in the application software are regrouped in a calculation server with a user interface to configure and run an off line analysis Using off line batch processing it is also possible to process a set of data items according to a given analysis script We present in the following paragraphs the procedures allowing the user To generally manage measurement session datafiles open save close print copy paste etc To sort measurement d
153. ion FBIH1_0 Cross transfer function FBH2_0 Inverse cross transfer This processing produces from the autospectrum Gyy of the function output signal and the cross spectrum Gxy between the input and FBIH2_0 the output the transfer function defined by Gyx Gyy U O r ER Q LL a ul LL U s This processing produces from the autospectra Gxx and Gyy of Coherence the input and output signals and the cross spectrum Gxy between FBCOH_0 the input and the output the coherence defined by Co Gxy Gxx Gyy Autospectrum or cross Derivation Integration Integration or derivation of an autospectrum or a cross spectrum spectrum FBID_0 acceleration velocity displacement acceleration velocity Displacement DERIVATION INTEGRATION PAGE 67 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Operator Default name Description Result A Signal item Convolution This operator performs the convolution of a signal by an impulse and an CVL_0 response Impulse gt Response CONVOLUTION Histogram Histogram of a global quantity with selection of the class bandwidth in HISTO_0 dB and limits HISTOGRAM Narrow band cross spectrum with time history capability narrow band multispectrum and frequency zoom The user specifies the FFT window 2 Signal items the overlap and the number of lines Cross spectrum FBG12_0 DUAL AUDIO ANALYSIS Broad band spectrum r
154. is data item It is the name of the operator for an off line analysis and the name of the acquired quantity for a real time measurement Date and time of the data item corresponding to the date of creation or modification Location defined during acquisition Channel 1 by default For cross spectra it corresponds to the location Location of the first measurement channel Duration of the data item hour minutes seconds Period Base duration or integration time of data items that vary with time Average type Type of averaging method used to compute the data item average min max statistical Average E Duration of the averaging for the element calculation duration Y axis Physical unit or dB for the histograms of the Y axis X axis resolution Resolution of the X axis in seconds for time histories of data items frequency resolution for spectrum data items Minimum frequency value ma mam teen ale OSS xais Unit of the X axis Hz seconds etc information noma onthedenent OOS O O Comments Comments othe dts tem fem measurement setup or ter medication For off line analysis this field indicates how this data item was computed ID of the original data item Track name and type of operators used to compute the result Sourcefile Name of file imported to dBFA format Name of the format INT UINT FLOAT PAGE 48 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 6 Editing and runnin
155. is set to 6 and the emergence to 5 dB for a peak to be a maximum its level must be greater by or equal to 5 dB than the two values located 3 lines before and 3 lines after These parameters are defined for all measurement sessions and do not need to be reset They must however be adapted to the different types of spectrum encountered Launching maximum search and calculation of interpolated values Open the plot of the spectrum to analyse and launch the search for the maximum using the t button or use ili to launch the search for a defined number of maxima number defined in the Preferences menu 10 xl Fal If peaks meet the search criteria defined in the ela E a a 2 tod eg Fi Display spectrum CMG1 ID 4 preferences cursors will label the detected ID 4 Average G1 Hz dB 2 C 50 000 Hz FFT resolution maxima on the plot and a table listing the results 1o i l E Yi Decreasing level Frequency f 7 or the interpolation calculations will be 120 Sate cette nse EN eee ane tae MSI ES AE sate e goths 2884 4 11278 di d p ree oe ee betas ere apes Peed 5768911048 ISpiayed ah nda rae Boece AE e es Nee eee eee PERES E i 91 0 T ec E eae eee TETAS Use in the table to have it always in the ey a S ada seated te ra lone re i l 144222 81 0 foreground o 17306 6 2000 4000 6000 28000 10000 12000 14000 16000 19000 2
156. ition in wavelets AUDIO ANALYSIS Pseudo Wigner Ville This processing performs smoothed pseudo Wigner Ville transform WVI_0 of a signal AR Model This processing performs an autoregressive modelling on a fixed AR_0 length sliding window ees This processing performs a Morlet wavelet decomposition Tachometric Speed conversion RPMTACH_0 This processing yields the speed in rpm versus a tachometric signal acquired on an input channel Sums up all the selected quantities The user may choose either to From 2 perform an arithmetic or an energetic sum Do not apply to complex spectra Addition PLUS_0 signals autospectra Leq Cross spectra Transfer functions Averaging Average all the selected quantities The user may choose either to coherence MOY_0 perform an arithmetic or an energetic average complex spectra Subtracts all the selected quantities The user may choose either to perform an arithmetic or an energetic subtraction Do not apply to complex spectra Subtraction MOINS_0 ARITHMETIC This function exports the input quantity to the MATLAB format MAT file This file can be directly processed into MATLAB with the load function Export in MATLAB format MATLAB_0 Export in 01dB Metravib WAV format WAVO1DB_0 This processing exports the input quantity at the WAV 01dB 1 or more Metravib format WAV file Windows compatible signal items EXPORT Export in MP3 format This proc
157. ive slope Slope y 30 ee Threshold value O Gains When the option Linked is active the gains on all active measurement channels are modified the gain setting of one active channel leads to identical modifications on all active measurement channels The gains on the active channels are identical if the option Identical is activated Each setting of one channel is passed to all other active channels This option is only available if the option linked has been chosen J E Autorange ul 0 Start automatic gain setting according to the input level on the hardware platform The autorange proceeds as follows during the duration defined in the dialogue box the programme stores the highest reached value and adjust the gain so that this value is located x dB margin defined in the dialogue box below that maximum measured value U Units Definition of the display unit of the input level The gain view meters may display the input levels according to three different units dB Display the view meters in physical decibel This is a relative level in dB calculated according to the transducer sensitivity and the reference O dB of the transducer type ADC Display the view meters in converter decibel This is a relative level in dB The level O dB is defined as the full scale of the converter The values in dB ADC are always negative between 0 and 90 dB Unit Display of the view meters in physical units In case the tran
158. l and Speed profile items in the order extraction module without using the batch window Batch Order extraction gt To do 1 Ja x MO ID Origin Status porelle CMG Order analy SUCCESE le CMG oe e The status of the processing is shown for each element as well as its origin target session and its porelle CMG Order analy n progress g targ a a Tne se dci de NEO AS A identification number ID in the session ol porelle CMG Order analy Todo Group by 2 e PAGE 161 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A al Transfer selected items from the session to the batch e Sort signal recordings for analysis IE E Reset the batch For all items in the batch the status changes to To process This function can be used to restart an analysis using a different windowing on a set of existing recordings Deactivate the processing for the selected items status Inactive Delete selected items from the batch E E e Delete all items from the batch Group by 1 to 4 Process elements one after the other or by groups of two to four multi channel recordings If there is an odd number of elements to process and if they are grouped by two the last element in the batch becomes inactive it will not be processed 9 1 2 2 Analysis set up e A extraction or Actions Parameters F5 to define the measurement and analysis parameters for the order Paramete
159. l to atan Gxyi Gxyr Where Gxyr et Gxyi respectively designate the real and imaginary part of Gxy 6 By convention the cross spectrum between a 50 dB sinusoid and a 60 dB sinusoid of the same frequency gives a level of 55 dB PAGE 71 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Broad band analysis from octave bands to 1 48th octave bands with selection of the method FFT narrow band recombination for 5 lines minimum or Class 0 standardised digital filtering A time integration can be selected to generate a multispectrum In both cases the algorithm uses undersampling in order to optimise the ratio between the sampling frequency and the maximum frequency of analysis Then for each octave band below the highest one the signal is undersampled by a factor 2 in order to keep this optimal ratio for each computation pass We therefore obtain a fast simple and reliable algorithm allowing the analysis to reach low frequencies FFT synthesis This method is based on the computation of an autospectrum in narrow bands in accordance to the previous definition The narrow bands are then recombined sum as a function of the broad band limits octaves and sub division of octave bands and the frequency band calculated However FFT synthesis of a broad frequency band is allowed only if 5 narrow band lines are included in this range Advantages of the method L Fast Reliability of the FFT algorithm Drawbacks of the method L Low fr
160. lt ref ref 10 log Cx Cy The phase of the result expressed in radians is equal to The phase difference between spectra Yf and X f Frequency response function H1 If x is the input signal and y the output signal of the process the transfer function H1 is defined as Y P A f X P The analyser calculates only autospectra and cross spectra The first method is then to multiply the above equation on both sides by the conjugated Fourier transform of X f i e X f From the Gxy cross spectrum and the Gxx cross spectrum one obtains an expression called H H Gxy Gxx The modulus of the result expressed in dB is H ny Y ref 20108 H is the module of the frequency response function If the selected physical unit is not the IS unit and if a conversion factor Cx is calculated e g Cx 9 81 for an acceleration level expressed in g then the expression above becomes H C X 20 log ref C Y of The phase of the result expressed in radians is equal to The phase of the Gxy cross spectrum PAGE 99 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Inverse frequency response function 1 Hi If x is the input signal and y the output signal of the process the inverse transfer function 1 H1 is defined from the cross spectrum Gxy and the modulus of the autospectrum Gxx 1 H1 Gxx Gxy The modulus of the result expressed in dB is equal to 1 H X
161. lways negative between 0 and 90dB V Dynamic display in Volts Physical unit If the transducer is a microphone the dynamic is displayed in Pascals Pa if the transducer is an accelerometer the dynamic is displayed in Acceleration m s2 For sound and vibration quantities of type autospectrum cross spectrum and transfer functions it is possible to select the following display units dB Level in decibels of the considered quantity Leq Slow Fast Impulse etc RMS Root Mean Square Average quadrate value for all the instantaneous squared values expressed in physical units PWR Power The power represents the average of a squared value It is the unit used to determine the power at a given frequency for a determined sinusoidal signal It is expressed in squared units Refer to paragraphs 11 3 and 11 4 for a detailed list of the frequency weightings and spectral units available in ABFA The levels are calculated from international system units SI It is possible to modify the default values with the command Preferences Units management See paragraph 11 1 It is possible to display up to two signals on the same graphical view if the data items have the same characteristics periods duration Signal plot Extrac d ordres CMG 3 2 Oj x Deltas 65 263 3 pt lis naaa STE 20 30 40 50 60 70 80 90 100 110 Envelop ID 1 Ch 2 s Pa MEE 0 048 115 17 0 046 PAGE 28 DBFA SUI
162. ly Jerk acceleration speed or displacement signals PAGE 92 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 20 Statistics operator STAT This function is used to calculate statistical indicators such as average maximum minimum standard deviation and Kurtosis on a signal The dialog box shown below is displayed on screen STAT_0 Statistics J xj Operator Configuration In the Configuration tab the following analysis parameters may be I Minimum abscissa 4 Average defined 4 Maximum abscissa I Standard deviation e Time in unit W RMS value ECN Check the elements to calculate e Time in points e Skew asymmetry i Minimum value e Kurtosis flattening M Minimum localisation The Operator tab gives an overview of this type of processing I Maximum value function and allows the user to modify the default name of the 4 Maximum localisation operator Save the result Annuler Default script Statistics C CisS Default name STAT_O Applies to 1 item Result family Results table 4 6 2 21 Sliding statistics operator STATGLIS This function is used to calculate statistical indicators such as average maximum minimum standard deviation and Kurtosis on a signal with a sliding calculation window The dialog box shown below is displayed on screen STATGLIS 0 Sidna A In the Configuration tab the following analysis parameters Operator Configuration may be defined Calculation paramet
163. m 23 Mean pressure 3 m Start and end date and time Active intensity a i Reactive intensity 3 m Number of data items of each family Free field intensity 3 Bark 1 i i i z and 3 tee This list is updated automatically each time a modification is made into the Transfer function H2 2 measurement session datafile Transfer function 1 H2 1 Cross spectrum 16 H 3 2 3 Measurement session comments Cmg E semple CMG general comments on the gt meausrement session Use the command A General Session comments to input a general comment for the active measurement session datafile OK Cancel Comments are visible in the measurement session information window 3 2 4 Playback of signal recordings OT fx Select a recording in the list and use the command Datafile Replay to playback L 69 A 69 Cmg a recording through the sound system of the computer signal output of SYMPHONIE or integrated sound card The dialog box shown aside is displayed on screen during playback When a plot is displayed in dBFA a vertical cursor follows the progress of the playback on this plot 3 2 5 Delete data items Select the data items to remove in the list and use the command T Edit delete or the Delete function key After confirmation of the deletion the data items are completely removed from the measurement session file PAGE 23 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 2 6 Modify data items editing Selec
164. m in dB presenting the statistical distribution of the levels per class in 4 6 9 1 Histogram Operator HISTO This processing produces a histogram of an overall quantity The following dialog box appears on screen HISTO_0 Histogram Operator Configuration Notification Class dB 05 E Lower limit dE Upper limits dE I Centred classes Number of classes 161 fom J 19 75 20 25 to 3375 100 25 I Save the result Annuler In the Configuration tab the following analysis parameters may be defined Class Select the class width in dB of the histogram to compute 0 1dB 0 5dB 1dB 5dB or 10dB Limits Select automatically or manually the lower and upper level limits in dB for the different classes of the histogram As a function of these limits and of the resolution of the histogram the number of classes of the histogram is also given In manual mode option Automatic centred limits not activated it is possible to select or not the option Centred classes for each class to be centred on an integer value of the dB levels The lowest and highest classes are also given as an indication The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name HISTO_0 Activefor Leq Leq Peak Fast Slow etc Apply only for one item Family of the result Histo PAGE 119
165. maximum Bark bands used for computation of the psychoacoustic criteria An indication of the frequency range covered by the analysis for any given Bark band is given Select the type of sound field free or diffuse to compute the psychoacoustic criterion The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default name PSYEV_0 Activefor_ Signal impulse response Default script Apply only for one item Family of the result Leq PAGE 115 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 8 Exporting time signals These operators are used to export audio events at the MATLAB format MAT file that can be directly processed into MATLAB with the load function or the wave 01dB Metravib format WAV files compatible with Windows 4 6 8 1 Export to MATLAB format Operator MATLAB This function exports the input quantity to the MATLAB format MAT file This file can be directly processed into MATLAB with the load function The following dialog box appears on screen MATLAB_0 Export to MATLAB format In the Configuration tab the following analysis parameters may be defined Operator Configuration Notification Export directory PPP Export directory ESO Select a folder on the computer hard disk for storing the audio events that have been exported MAT files Hoot Index a dB_wawe_ fi 2 The key allows the u
166. mber Use this command menu About dBFA to obtain general information on the software version copyright and licence number About DBFA32 x Version 4 404 Copyright 01 dE Stell 002 License number AAAA AAA If the licence number of the software module has to be modified click on the key Licence number The following dialog box appears on screen Edition of the license number Application POOR HOOK cancel Enter the new licence number provided by 01dB Metravib technical support Start again the application software in order to account for this modification PAGE 186 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 8 Generating signals with dBGENE The dBGENE software is used to generate different types of signals via the computer sound card or the acquisition platform An amplified loudspeaker or even a shaker can thus be controlled The following signals can be generated by dBGENE White noise Pink noise Sine Frequency modulation Playback of WAV files Generating a signal on the acquisition platform is only possible with SYMPHONIE or HARMONIE with Windows 98 and Windows Me 11 8 1 Presentation of dGBGENE The figure below shows the overall interface of dBGENE from which all generator functions are available 1 dBGenerator white noise Pink noke Sine LFM WAY file Gain dB fo W Limited duratio 20000 me Sound 4 Digital Audio
167. me portion between cursors IN Zoom out the plot OUT Display or not a millimetered grid on the plot 3 3 2 2 Data parameters for the graphical view Define data parameters for the graphical view using Plot Parameters The dialog box shown below appears on screen The tabs allow the user to define the following parameters Fisted by default To set default parameters just check box and click on OK Apply or Apply to all X axis Frequency tab Display parameters setup a x Frequencies Data Overall levels Graphics Wee In this tab select the minimum and maximum frequency bands for Min 315 y spectrum display in the graphical view Max ick y a If the All box is ticked the spectrum is displayed over the complete frequency range of acquisition Annuler Appliquer Appliquer tous Fixer par d faut PAGE 30 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Data tab Display parameters setup x Frequencies Data Overall levels Graphics In this tab select if the data should be displayed in physical units Dynamic Lin or Log or in decibels dB Optimize EmO rm Then select the required spectral unit RMS or PWR for broad band Dynamic dB spectra and multispectra as well as the frequency weighting to ES apply to the spectral data values If the Optimise box is not ticked the user may then select the minimum and maximum values of th
168. milies Only applies for one item Family of the result Signal Impulse Response families PAGE 83 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 5 Notch filtering Operator NOTCH This analysis results in a notch filtered time signal The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined sa Al Attenuation frequency Fa define the rejection frequency in Hz Operator Configuration Notification Filter order Select the Butterworth filter order between the following values 2 4 6 8 10 12 14 16 18 20 22 24 26 28 and 30 Attenuation frequency Hz 414 21 Filter order 10 Selectivity factor 10 Selectivity factor S Define the selectivity parameter 10 20 40 or 80 The user defines the filter selectivity S factor The frequency range at 3 dB is then of fs PI S for an order 2 By increasing the order number attenuation is emphasised at the expense of aelectivity I Save the result OF Annuler The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name NOTCH_O Activefor __ Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families 4 6 2 6 Frequency A weighting Operator WEIA This analysis results in an A weighted time sign
169. mo olem level CONVE TOA A a A A A td 24 3 2 6 4 CUEING OR Items SU Z E E A 25 52 65 Autospectumiypo Of ona De ek kareena e aed E iad cha ean ene ld ead nd ch eae ie 25 3 2 6 6 OEM ALON IA A A A dd A dd 25 ds PEORDATA ITEMS GRAPHICS Monda 26 O AS A e e o o 27 3 3 2 Broad band spectra and or multispectra Bark bands histograms and echogram ooon 29 3 3 2 1 Display parameters OLSEN E RAE 30 A Data Parameters TOTS A a ss 30 3 3 3 Narrow band spectra and or multispectra transfer functions and coherence ooooonnnnnnnnncnccccococoncnnnnnnass 32 3 3 3 1 Display parameters 0f the graphical EN ld dt dd 33 3 332 Dataparameters for he graphical e 33 3 3 3 3 Using harmonic sideband and maximum Cursors oococcncnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninnnss 36 Ids SORA yi EW paS a a chase estas ante 40 3 3 4 1 Secon USOE aa a e ae A a set lautedecendteeetecencquealscas 40 3 542 DMA ke SO S e ene llei ene are 4 3 3 4 3 COME SCA Cie A ne Deas es se secs ea nesses eae a ene esd eee lea esc eee eee 41 3 3 4 4 Datacalculation parameters tor dis placa e R EAE ean thsseMianateasaadisauteends 4 3 3 4 5 A ELET A eee whee thee scree O ce etc cee Se Seah cecal ele Lk es Pee at ee nants 43 3 3 4 6 UI A e eteccsmedens 43 e O E A a Rosetta Sees Ota a Rese Si sen A Pee tic aac eee 43 IAs Data Calculation parameters Tordis play nerna aa e e t 44 OO LOEN CW tt si 45 l Important Notice Because this software package
170. n A column Fields column Frequency resolution of a broad gt et eee band spectrum or multispectrum ee el das ei eo ed Name of the application software Appucation used to create the item ASMA Alpha p Alpha w Alpha s D French standard D ISO standard Dn w Dn T Dn T W DnT DnAT pink DnT DnAT route Unknown Ln Ln w L n L n w LnT LnAT L nT L nT w R Rw R Rw User comments on the item Manual input i Manual input day month year hh mm ss Date of creation of the item A e 01 02 1999 16 42 05 gt Manual input ddd hh mm ss ms Duration of an item gt 30 seconds 000j00h00m30s000 attack decay sustain release signal autospectrum clarity code coherence comment counter room criteria EDT transfer functions 1 H1 H1 1 H2 H2 histogram Nb cumulated histogram Nb Intensity active reactive free field cross spectrum sound insulation Leq measurement mean pressure psycho RASTI impulse response sensitivity Bark spectrum scalar spectrum STI TI TR Name of file imported to dBFA Manual input Name of the format _double _float _int16 _int24 _int32 _int64 _int8 _uintl6 _uint32 _uint64 _uitn8 Bits Type of quantity allowing us to define more accurately the data item Data type for a Fast sound pressure level the family would be Leq and the data type will be Fast aoe Physical unit of the X axis Bark dB Hz Order Scalar quantity Y1 axis Phys
171. n Curve The programme enables the user to display as much lines as wanted in the real time measurement window and offers the possibility to superimpose several curves on the same view when the curve types are compatible An example is given below PAGE 152 DBFA SUITE USER MANUAL Display of curves Line spectra sxx 1st pass a 1 xx 14 Li 1st pass Li 2nd pass gb_dBFA NUT 043 A Je JE e Jia ln Jr Hz dB Ref 2 000e 05 Pa RMS SE AE Hz dB Ref 2 000e 05 Pa RMS MA TENA DOI ARRE TT TA AN O if Line spectra is marked the bar spectrum is replaced by a line spectrum An example of a spectrum with the same signal in the two modes is given below Hz dB Ref 2 000e 05 Pa RMS Hz dB Ref 2 000e 05 Pa RMS Bar type spectra Hz 000e 05 RMS Hz dB Ref 2 000e 05 Pa RMS A 125 20 500 A 2k 4k 8k 16k Line type spectra PAGE 153 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 3 2 Display dynamic configuration Use the command Display Y axis to select the display dynamic manually The following dialogue box appears on screen fas Min 20 0 hax BO 0 Cancel The defined parameters are only applied to the active curve after validation of the dialogue box This dialogue box allows the user to modify the unit of the Y axis as well as the minimum and maximum values of the used scale There are two possible display units
172. n intensity calculation With the phase correction the user may correct the measured values in relation to the intrinsic phase shift of the probe that is included in the phase correction file defined in the hardware configuration The option Convolution correction allows the user to activate the convolution correction during an intensity calculation With the convolution correction the user may correct within a limit of 3 dB the high frequency error due to the approximation of the pressure gradient When the option Warning message if parameters are adjusted is validated a dialogue box appears during validation of the current dialogue box to display the adjusted parameters if needed When this option is inactive the programme adjusts automatically the parameter values in relation to the possibilities of the acquisition unit The option Autorange starts automatic gain setting at the start of each measurement Storage modes Choose Autospectra cross spectra and intensity in order to save after starting the measurement the auto spectra and if necessary the cross spectra as well as the intensity spectra active and reactive intensity and the mean pressure level spectra The octave band third octave band and narrow band first and second pass FFT spectra for each quantity are stored in the measurement session datafile Choose Displayed quantities in order to save after starting the measurement only the spectra that are displayed i
173. n the real time measurement window Choose Customise in order to carry out a personalised storage The programme stores the curves accessible for the current operating mode To define the quantities to be stored click on the button Define the dialogue box custom results storage appears Custom results storage Mo Type Chis The list on the right indicates the different spectra types and its channel references that may be stored xx 2nd pass Li 1st pass Lp ist pass xy 1st pass Coherence 2 SIL 1st pass SIL 2nd pass SIL 1 3 Y Remove l OK Cancel The list on the left indicates the different spectra types that will be stored after validation of the measurement results xy 2nd pass 1 2 The cross spectra intensity spectra and the mean pressure level spectra are only accessible if the cross function computation is activated Reminder Gxx Autospectra Gxy Cross spectra Li Active intensity Lj Reactive intensity SIL Free field intensity LP Mean pressure levels 1st pass first FFT pass narrow bands 2nd pass second FFT pass narrow bands 1 1 octave bands 1 3 third octave bands To activate data storage of a given spectrum select its type and the reference channels Then use the command Add in order to add the spectra to the storage list left hand side The user can also carry out this action by double clicking on its representation in the right hand side list PAGE 148
174. n vibration measurement and Wj vibration measurement under head of recumbent person related to comfort issues in specific cases E Principal weighting Wf to evaluate the adverse effects of vibrations on human beings relative to motion sickness Principal weighting Wb to evaluate the adverse effects of vibrations on human beings relative to comfort issues in given environments vehicles on rails for example ISO8041 and ISO2631 part 2 Principal weighting WBc all directions combined to evaluate the adverse effects of continuous and shock induced 1Hz to 80Hz vibrations in buildings 1808041 and 1805349 Hand arm weighting Wh all directions to evaluate hand transmitted vibrations PAGE 181 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 4 Spectral units display types For signals it is possible to select the following display units ADC Displays the dynamic in dB converter It is a relative decibel level The OdB level is the full scale value of the converters i e a sample which has a numerical value of 2 16 32767 corresponds to the OdB value dBADC values are always negative between 0 and 90dB V Dynamic display in Volts Physical unit If the transducer is a microphone the dynamic is displayed in Pascals Pa If the transducer is an accelerometer the dynamic is displayed in Acceleration m s2 For sound and vibration quantities of type autospectrum cross spectrum and transfer functions it is poss
175. nanas 139 TABLE OF CONTENTS PAGE 7 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 7 MEASUREMENT CHAIN CALIBRATION cccsccccssseceecnseceeensenseeuseneeeaseneeneeaasenesoaseneeaaseneeeneeaasenseaaeens 141 8 INTENSITY MODE sesssisctsctiwtadciasadensatewucwdadsacac aceuiudassassdaascsabeatusdsasnedsvessudewastunsiscaunaweseuti iantsnedsgadeunies 143 8 1 MEASUREMENT WINDOW OVERVIEW assi 144 8 2 MEASUREMENT SETUP Sea Seeder EE E E a E 146 a AS SS TE E T WEEE OC TY 146 S22 AGGUISTIION PAIGINE 1 CIS A A ia 146 SZ AVENA Sine DAMOS is a alta 149 Sa A Aerial sienai Sener OF OPON srra iien ea e e NN A A ERR 149 S252 Threshold gainanddutorange settings sisese reii a a a A 150 8 3 DISPEA CONFIGURA TION crire as 152 SSe SAA A A E OZ Sa TIISDIAY dynamic COR CULO ii Se iia 154 A TOA A a ae cas ice 154 A ee 154 E MOME CUSO N e A A ea eee 155 8 3 6 Integration Derivation of spectra to be displayed ooooooonocononocconononnnnnonononnnnnnnonnnnnnnnnnnnnnnnnnnnnnnnnnos 156 8 4 MEASUREMENT PROCES Direi r en a a aa 157 9 ORDER EXTRACTION AAA Co aaa 159 oI POST PROCESSING ANALY SiS lied 160 9 1 1 Description of the analysis WINDOW vic ss 160 TL VATU SUS SE AAA a A ed easier ean dele caceera cata celae 161 9 1 2 1 Batch window denise 161 022 AMAS ld al il lol al lil teal 162 VAS IIESI UA E a ONA 164 9 1 3 1 DIA A a 165 9 1 4 Description of a post processing Order CXtVACTION cccccccccccccee eee aaa aaa 165 10 REMOTE CONTROLS AN
176. ncy analysis LJ Either in real time please to the chapter concerning Analyser mode in dBRTA user manual L or in post processing mode BOE files on existing recordings in this case the tachometric signal can be acquired on a dynamic channel to be analysed more precisely In this chapter only the post processing mode is described Caution Do not mix up order extraction and order tracking During an order analysis with order tracking the signal is sampled according to the system rotation speed Whereas an order analysis with order extraction is carried out from a FFT frequency analysis POST PROCESSING Open a session and select signal recordings 5 cm63 Main window Allitems ES Gill S Family Datatype W Name Date location ___ 1 0 Signal Instantaneous Lin 18 12 95 16 26 27 mont e moteur gt Voie 1 1 Top Tour Instantaneous Lin 16 12 95 16 26 27 mont e moteur gt Voie 2 2 Speed profile Instantaneous Lin RPMTACH O 18 12 95 16 26 27 mont e moteur gt Voie 2 Process recordings windowing averaging 1250 000 1000 000 500 000 Add autospectra cross spectra transfer functions to the measurement session CMG3 Main window Allitems y S CER Tents one IR Signal Instantaneous Lin 18 12 95 16 26 27 mont e moteur gt Voie 1 Top Tour Instantaneous Lin 18 12 95 16 26 27 mont e moteur gt Voie 2 Speed profile Instantaneous Lin RPMTACH_O 16 12 95 16 26 2
177. nd spectrum Operator FE inrer enrio ei ena naa E EE ae 76 4 6 1 5 Pseudo Wiener Ville trans lorim operato esiisa e e AA E AN TI 4 6 1 6 NlOomlet wavelee alts OT Opera O en a E E a aS ET E I7 4 6 1 7 Autorerressive modelini O AI ad 78 4 6 1 8 Capontiansto rtorras ld ds a ed do Oe 79 AO OPINAS OS A daras SU 4 6 2 1 Low pass filtering Operator ILOW Perenci a aches es ee ees 80 4 6 2 2 PIGH pass tonns Operator HIGH taa 81 4 6 2 3 Band pass Operator PASS dieras 82 4 6 2 4 Cui band Hierin Operator CUT ea ae ete ee 83 4 6 2 5 Notch termo Operator NOTCH k aaa a a as 84 4 6 2 6 PTEQUENCY A w ishtine Operator PW ETA jccusene dec ee Wee See nities eee eee 84 4 6 2 7 Frequency B weighting Operator MEM iaa 84 4 6 2 8 Frequency C weichtne Operator WEIC i2tcc reso oan e cartes ea 85 4 6 2 9 Vibratory weighting Operator WEIWB WEIWC WEIWD WEIWE WEIWF WEIWG WEIWJI WEIWK WEIW BE iaa as 85 46 210 7KB weisntine WEIWEKB Ra 85 AZ WV iO wits Operator WIN aint artist aii dida 86 4 6 2 12 Resampling operator SAMPLE a ate ec 88 AZ LS lt Garm optinasattom AUN aaa 88 40214 Undersamplino Operator DECIM pao da las del a a 88 A62 15 Denoisine operator DENO Sii o ana a r a teaches 89 A A asec ican voreietascbniegncusni asset ehcac ios staatiieds E 90 AZ Calewlaionor EKB and KBE RT sionals csc coe li cd 90 4 6 2 18 Operator Pulse to RPM profile conversion RPMTACH ccccccccccceeee
178. nel 1 Autospectrum Channel 2 Cross spectrum Channel 1 Channel 2 None Default name Family of the result 4 6 4 3 Frequency response function H1 Operator FBH1 This processing produces from the autospectrum Gxx of the input signal and the cross spectrum Gxy between the input and the output the frequency response function defined by Gxy Gxx The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Frequency response functions Default name FBH10 Autospectrum Channel 1 Autospectrum Channel 2 Cross spectrum Channel 1 Channel 2 R a Check the compatibility of the physical units the type of data estrictions RE the weighting window frequency and time resolution Family of the result Frequency response function H1 4 6 4 4 Inverse frequency response function 1 H1 Operator FBIH1 This processing produces from the autospectrum Gxx of the input signal and the cross spectrum Gxy between the input and the output the transfer frequency response defined by Gxx Gxy The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Frequency response functions Default name FBIH1_0 Autospectrum Channel 1 Autospectrum Channel 2 Cross spectrum Channel 1 Channel 2 Check the compatibility of the physical
179. neral operations on the measurement session datafiles Description of the measurement session window comments information window delete data items display graphics and table of results export data into a spreadsheet or word processor start an off line analysis start a batch analysis Requests sort data items Edition of requests execution of requests LU The different types of off line processing functions as well as the analysis process are dealt with in chapter 4 LL Batch analysis is dealt with in chapter 5 E Be careful if you have the ISO9614 module for sound power determination the measurement session can be displayed as standard see this chapter or in a specific manner Refer to the corresponding application note in the latter case 3 1 CMG datafile management A measurement session data file with the CMG extension may represent several megabytes of data and dBFA may work simultaneously on several data files In order to facilitate session management elements can be moved from one session to another by dragging them with the mouse like in Windows Explorer 3 1 1 New CMG datafile i To create a new measurement session datafile CMG that is empty click on the icon or use the File New CTRL N command An empty measurement session is then displayed on screen PAGE 20 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 1 2 Open a CMG datafile To open a CMG measurement session file stored on th
180. ng the Preferences Units management menu See Section 11 3 3 4 1 Section Cursor The displacement of the cut cursors updates directly the section views Generally v The vertical cut corresponds to the spectrum for the time axis of the vertical cursor v The horizontal cut corresponds to the signal time history or RPM for the frequency axis of the horizontal cursor The user can change the time and frequency axis see Preferences Sonagram PAGE 40 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 4 2 Differential cursors The differential cursors allow the user to differentiate the X Y Z co ordinates on exact two points of the sonagram Initially these points are situated in the lower left corner point c1 and the upper right corner point c2 of the sonagram The co ordinates of these two points and the algebraic difference of the values of each axis see on the opposite are displayed at the bottom on the left of the window 10 St 100 3 3 4 3 Color scale The color scale according to the amplitude is displayed at the left bottom of the window The user can change the colors using the graphic settings box as well as customize personal colors User defined color palette The user can define a color palette for the display of the sonagram with a text file named User rgb that should be situated in the program directory The standard directory to install 01dB Metravib software is C Program Files O1dB Metravib T
181. nits Dynamic Lin or Log or decibels dB for data display imi eee as A Select the spectral unit RMS or PWR for broad band spectra and Y Optimize ams y Dynamic dB gt E Si multispectra RMS PWR ASD or PSD for narrow band spectra dB Min o Max 00 El al multispectra as well as the weighting to apply to all spectral a ata Select the weighting to apply to the spectrum Lin A B If the Optimise box is not checked then minimum and maximum values of the display dynamic range can be set here Annuler Appliquer Appliquer 4 tous Fixer par d faut Refer to Sections 11 3 and 11 4 for a detailed list of frequency weightings and types of spectral units available in ABFA Plot type tab Frequency Data Plot type Main axis Choose in the Plot type tab Palette Sonagram o renee v The color palette to display the amplitudes see also user Hot E Monero palette User width 3 JP Y Sonogram or waterfall display Heigth s 20 Annuler Appliquer Apply at all Fixed by default PAGE 42 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Main axis tab Select in the Main axis tab the the beginning and the end to display the Reinit button allows to display the entire recording 3 3 4 5 Zoom One can display a detailed part of the sonogram by enlarging the whole view Therefore you have to maintain the SHIFT key of the keyboard and defin
182. nnuler Default script History of overall loudness Default name BGLOBAL_0 Bark spectrum Applies to one item only Result family Overall either time history or data table PAGE 109 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 7 Psychoacoustics Various operators allows the user to compute psychoacoustic criteria Stationary criteria It is currently possible to measure the sound intensity of a noise event in dB and therefore quantify the nuisance level they may cause Standard techniques however are too simplistic to account for the subjective nature of human response to noise Psychoacoustics is a relatively new branch of psychophysics that addresses this problem A number of parameters have been defined in order to take account of the subjective nature of human perception and judgement of sound quality E Loudness Loudness 10 O Fluctuation Strength E Sharpness L Tonality E Roughness LL Unbiased Annoyance a combination of Sharpness Fluctuation Strength and Loudness 10 E Sensory Pleasing Sound depends on Roughness Sharpness Tonality and Loudness criteria These criteria are defined in Psychoacoustics Facts and Models by Zwicker and Fastl Springer Verlag Ed Furthermore 3 types of Articulation Indices can be calculated O NHV Noise Vibration and Harshness for the car industry L Unikeller a variant of the Beranek method that does not have indices limited to the range 0 100 UU Rooms gener
183. o Define how to synchronize the results with the rpm values beggining middle or end The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name OA_DFT_O Signal Speed profile families Activefor Items should belong to the same measurement Result family Global RPM Autospectrum PAGE 132 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 12 5 Order filtering operator This operator uses an order tracking time filter from a speed channel Filter characteristics min max order as well as tracking timing are user defined FIO_0 Order filtering x Operator Setup In the Configuration tab the following analysis parameters may be defined Filter type Band pass Filter type Define the type of filtering to perform low Min order 05 pass high pass band cut notch Max order E Min max order Define the frequency ranges used by the Tracker filter updating filter Rate f 0 ms Tracking filter update Define the time interval for tracking filters Save the result Annuler The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default scrip Default name FIOO gt O Signal Speed profile families tems should belong to the same measurement Result family Signal IIS 4 6 12
184. o each contact corresponding to an input or an output of a physical remote control in order to perform a specific operation The input contacts generally connected to push buttons of a physical remote control can present 3 different states click double click and long push of a button An input message is assigned to each state The output contacts generally connected to flashing lights or LEDs can present 4 different states active inactive blinking and flash A contact state is assigned to an output message In fact each contact corresponds to a specific pin of the communication interface RS232 connector of a microcomputer MiniDyn connector of the SYMPHONIE Or HARMONIE acquisition unit When an input contact is activated a voltage is generated on this pin This voltage is then interpreted by the remote control object and the application software execute the appropriate input message When an output message is sent by the application software to the remote control object the output contact is activated and depending on its state a voltage is generated on the pin of the communication interface This voltage Signal is then interpreted by the physical remote control Remote control objects are defined in the file DBCD32 INI If you do not have this file in the 01dB Metravib program folder contact 01dB Metravib technical support to obtain a copy of it A complete description of this file is given in this manual Follow the procedur
185. of the significant harmonic and on the proximity criterion Spectrum Maximum cursors Harmonic S AN Zoom on harmonic 5 II NEAN re E Spectrum W Maximum cuxsOrs W Harmonic cresors A In the above example a spectrum is displayed showing the location of the interpolated maximum and of the first 5 harmonic cursors Harmonic cursors do not coincide purposely exactly with the physical phenomenon under study The zoom on harmonic 5 shows that if the proximity criterion dF is set to 100 there is a maximum in the resulting area Harmonic 5 is the highest in frequency and thus it is the Significant harmonic On the contrary if dF is set to 50 then the closest maximum to harmonic 5 does not belong to the defined area anymore Zoom on harmonic 3 shows then that if dF is set to 50 there is a maximum located in the defined area Harmonic 3 will then be the significant harmonic since it is the highest frequency meeting the proximity criterion O if there is a significant harmonic then the interpolation calculation can be launched The frequency and the level of the significant harmonic are interpolated then for each harmonic the level is interpolated from the cursor position The frequency is calculated according to the significant harmonic using the rule of 3 for the frequency calculation there can actually be an interaction between the w
186. ogress eae Note To delete an existing shortcut select a script in the list on the left then select None in the quick access list 4 4 2 Using shortcuts Once shortcuts have been assigned calculation scripts can be launched by clicking on the shortcut buttons in the session toolbar O select one or more items in the session depending on the operations to perform Shortcut buttons corresponding to operations compatible with the selected items are enabled E A Z E Click on the shortcut button to launch the corresponding script Note Shortcuts cannot be used in a batch analysis PAGE 65 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 4 3 Quick editing of a script associated with a shortcut A script associated with a shortcut button can be directly edited without going into the calculation server To do so click on the shortcut button for which you want to modify the script while holding down the Shift key SHIFT E EDITING 4 5 List of default analysis scripts and associated operators processing functions The table shown below gives a complete description of the default scripts contained in the calculation server with associated operators and types of data items it can be used with Operator cere Default name Description Result Order extraction From a tachometric channel and a measurement channel this operator performs the order extraction with a selection of the EXO_0 method constant resol
187. om Activation Deactivation of second cursor ui een CURSORS Cursor synchronisation if several curves are displayed The levels are calculated from international system units IS It is possible to modify the default values with the command Preferences Units management See paragraph 11 1 It is possible to display in a same window as many stacked curves as the system can handle regardless of their characteristics If the elements have the same units Pa m s curves can be superimposed Stacked curves Superimposed curves PAGE 29 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 2 1 Display parameters of the graphical view Set up the graphical display parameters using 1 Plot Plot set up The plot is updated immediately when a modification is made Each plot has its own settings dialog box a modification on one plot does not affect the settings of another plot Display or not the Y axis scale and select the graph Display or not X axis dynamic range constant range or set up manually scale the minimum and maximum limits Display spectrum Cmg Exemple CMG E Y anis Cursors Show Hide one or two eee I Scale 31 cursors on the plot lv Scale ao T Constant range Toe Vanous l i Show Hide cursors values Min fioo Iv Show and select channels M Grid A Ja gt Choice Max 50 0 Zoom Ti E Jos Zoom in the plot for the ti
188. op the input signal on the output of the hardware platform The generator is active when the box On Off is activated Frequency Hz 525 OK Cancel With SYMPHONIE the signal output level can be set by clicking on the A icon in Windows taskbar Select the acquisition platform and click on Properties to set the output level of SYMPHONIE Attenuation setting dB field Then connect an amplified loudspeaker to the output of the acquisition unit For more information on the acquisition system for instance output wiring setting of output volume please refer to the system installation manual PAGE 149 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 2 5 Threshold gain and autorange settings This dialog box enables the definition of gain and threshold settings These parameters can be used in several ways by the application software All parameters and the available actions may be enabled or disabled according to the acquisition module which calls this command Measurement channels Gains linked and or identification identical for each active Gains measurement channel Link J Identical Autorange Duratior 5 E z Parameters and automatic gain setting Marge fio de Enri autorange Trigger Direct Threshold D lay y me Parameters for measurement trigger Definition of physical unit for display Thereshold activation Direction of threshold trigger positive negat
189. or of the communication interface passes from the current state to OV E Blinking While an event is activated the voltage on the appropriate pin of the connector of the communication interface passes from OV to 9V RS232 or 5V SYMPHONIE HARMONIE at a user defined rate Cancel Flash While an event is activated the voltage on the appropriate pin of the connector of the communication interface passes from OV to 9V RS232 or 5V SYMPHONIE HARMONIE for a user defined period The drawing below illustrates the different states of the output contacts Event duration AV No use 9 V or 5V AV Active 9Vor5V Inactive AV 9 V or 5V Blinking AV 9 V or 5V Flash AV PAGE 171 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A For dBFA the table below gives the list of actions for each output contact FUNCTION STATE ACTION MEASUREMENT STORAGE Notify the remote control that the application software waits to start an acquisition Stop command 1 Notify the remote control that an acquisition is in progress Notify the remote control that the application software waits to accept reject the measurement result Start command 1 Start command 2 Notify the remote control that an overload occurred during acquisition CALIBRATION Start command 5 Notify the remote control that calibration is in progress Stop command 5 Notify the remote control that calibration is finished No specific software configuration is req
190. ory i be defined Operator Configuration Notification Synthesis frequencies Define the minimum and maximum frequency bands used to compute the overall level Synthesis frequencies Fhin Hz o Flax Hz 20000 Required weighting Select the weighting to apply to the computed overall level time history A B C and Lin Required weighting The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator e Save the result Annuler __Activefor___ Autospectrum intensity active reactive free field Apply to one item of the type broad band or narrow band spectra only Narrow bands require a common frequency range between the synthesis freq range and the data item freq Family of the result Leq Restrictions 4 6 6 3 Overall Loudness history Operator BGLOBAL This processing yields the time history of the Loudness or the Sharpness for a Bark band spectrum For a single spectrum the result is an overall level The dialog box below is displayed In the Configuration tab the following analysis parameters may be defined BGLOBAL_O Evolution de la sonie globale x Op rateur Configuration Select the magnitude to calculate The Operator tab gives an overview of this type of processing f Loudness Sharpness function and allows the user to modify the default name of the operator Sauvenle r sultat A
191. overall levels to compute according to a given frequency weighting displayed in a list Lin overall level between cursors User s Lin overall level It is possible to calculate and display a level between two fixed frequencies by checking the User overall level box and specifying a frequency range labelled U on the curve If two cursors are activated it is possible to calculate a Lin overall level between cursors labelled Ec on the curve To activate the second cursor see Section 3 3 3 1 Annuler Appliquer Appliquer 4 tous Fixer par d faut Refer to paragraphs 11 3 for a detailed list of the frequency weightings available in dBFA Graphics tab x Frequency Data Overall levels Graphics In this tab select the type of graphics that will be displayed line Bars mode or bar mode C Line Stair mode Line Mountain mode Examples of the different types of graphical representation are given below Annuler Appliquer Appliquer 4 tous Fixer par d faut Bar mode Line mode stair and mountains PAGE 35 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 3 3 Using harmonic sideband and maximum cursors O Maximum cursors Principle and operating mode The aim of this operation is to detect lines resulting from the FFT calculations that stand out most and then to get closer to the true value Frequency Level of the physical phenomenon using an
192. own settings dialog box a modification on one plot does not affect the settings of another plot Display or not the Y axis scale and select the graph Display or not X axis dynamic range constant range or set up manually scale the minimum and maximum limits Display spectrum Cmg Exemple CMG TE ES Y asis Cursors Show Hide one or two R M Scale 157 cursors on the plot Constant range Taine Show Hide cursors values Venous l Min joo Show and select channels q E E Max 50 0 Zoom 2 Hg Display or not a millimetered Zoom in the plot for the time grid on the plot portion between cursors IN Zoom out the plot OUT 3 3 3 2 Data parameters for the graphical view Define data parameters for the graphical view by the command a Plot Parameters The following dialog box appears on screen TT Fised by default To set default parameters just check the box and click on OK Apply or Apply to all The tabs allows the user to define the following parameters X axis Frequency tab Display parameters setup i x Frequency Data Overall levels Graphics In this tab select the minimum and maximum frequency bands for spectrum display in the graphical view Frequencies Hz Min 0 00 a E Max 20000 00 MM TA If the All box is ticked the spectrum is displayed over the complete frequency range of acquisition Lin Log Annuler Appliquer Appliquer 4 tous Fix
193. pass them into the list of active processing functions L Stage 4 Edit the required processing functions In the list of active processing functions select the function or operator to configure and click on the Edit button Repeat stage 5 and 6 for each active processing function L Stage 5 Configure the processing function In the Configuration tab define the analysis parameters UU Stage 6 Additional configuration In the Operator tab input a user defined name for the processing function L Stage 7 Execute the analysis script Once all set up operations have been carried out validate all the dialog boxes and click on the corresponding icon to execute the analysis script The various processing functions are then executed sequentially for the selected data items in the measurement session window The analysis results are then stored themselves in the active measurement session datafile Refer to chapter 4 for more details on the off line processing process PAGE 17 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 2 3 3 Batch processing It is possible to run a batch on a set of data to process a script on all these data For instance if the user wants to apply the same script on several items of the measurement session he can define a set of input items on which the script will be run automatically 210 x CMG1 Main window F Al items AE se 5 Sfl Fa Datatype w l Date location D Pe
194. ped e Storage in separated files the various elements of a measurement session items are saved in binary files The binary data of each item are stored in a BID file Binary Item Data and the references in the measurement session CMG The size of each item should not exceed 500Mo This storage is used by activating the option Save items in separate files e Storage in grouped file allows to gather the whole of the data in a single file CMG It s a container structure However the size of the CMG should not exceed 800Mo by including all acquisitions and treatments This storage is used by deactivating the option Save items in separate files PAGE 60 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 OFF LINE PROCESSING 4 1 Introduction Data processing in dBFA can now be performed in a global manner thanks to the implementation of analysis scripts Each processing operation is available as operators which assembled in series or in parallel compose an analysis script The scripts available in the application software are regrouped in a calculation server with a user interface to configure and run an off line analysis An operator can be represented as a black box with a single or several inputs and an output Each of them corresponding to data items stored in a measurement session datafile ITEM 1 OPERATOR RESULTING ITEM ITEM 2 Each operator has its own configuration dialog box allowing the user to d
195. quency analysis techniques when writing music scores PAGE 73 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 1 2 Narrow band spectrum Operator FB This analysis results in a narrow band spectrum with time history capability narrow band multispectrum and frequency zoom The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined A xi FFT Window Choose the FFT window for the analysis The following windows are available Rectangular Hanning Hamming Kaiser Bessel and Flat Top Operator Configuration Notification Frequencies Window Overlap Hanning 50 Overlap Choose the overlap factor for the analysis amongst the following quantities 0 25 50 and 75 Band 20000 000 Lines fen During a FFT analysis the overlap factor represents the percentage of samples that are used simultaneously in two adjacent data blocks 10000 000 FOOO 000 15000 000 12 500 0 080 a e Multispectra fo z 125 me Max frequency Select the maximum frequency of the analysis The pass band defines the maximum frequency of the analysis A scrolling list indicates the available maximum frequencies le Save the result UK Annuler Lines Select the number of lines for the FFT analysis amongst the values displayed in the list 101 201 401 801 1601 or 3201 The higher the number of lines the highe
196. r Default script Signal analysis Default name RPMTACH_0 Activefor 1 Signal item Applies for 1 item only Result family Speed profile PAGE 91 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 19 Integration Derivation operator DIN This processing allows for the integration or the derivation of an acceleration speed or displacement signal The dialog box shown below is displayed In the Configuration tab the following analysis parameters may be defined Operator Setup Integration Derivation Use this field to integrate derive signals Integrate E Derive Mm i le Move the cursor to the left to integrate the signal once first tick Deryvate 1 times Move the cursor to the right to derive the signal once first tick twice second tick or three times third tick he Save the result Annuler The table below summarises the different integration derivation options depending on the type of signal Integration Derivation Data type 1 2 3 1 Nomenclature Jerk m s Acceleration m s2 Speed m s Displacement m The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Integration derivation Default name Active for Acceleration speed displacement signals Applies to one item only Restrictions The number of derivations or integrations should be compatible with dimension units Result fami
197. r the frequency resolution FFT zoom This group allows the user to define the parameters of a FFT zoom The zoom allows the user to reduce the frequency range of analysis around a centre frequency and thereby increase the frequency resolution Select Zoom in order to activate the FFT zoom option Then choose the centre frequency and the zoom factor The curve on the left hand side informs the user about the chosen parameters The red information bar lower part indicates the analysis frequency range while the spectrum indicates the chosen frequency resolution To modify the centre frequency or the minimum frequency when the Zoom option is activated of analysis move the cursors respectively to the right and to the left The user can also modify the zoom parameters by setting the zoom factor and the centre frequency in the right part of the dialogue box Multispectra if this option is activated the user obtains the time history of the spectrum over the item duration The time step may vary from 1 ms to 999 ms The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name Activefor Signal Impulse Response families Restrictions Only apply for one item The length of a time block must smaller than that of the signal Family of the result Autospectrum PAGE 74 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A
198. rder HA Max order E Speed range Definition of the speed range for the whole study It anclas Em should include the speed profile sequence of run ups and or coast Min speed 500 Max speed 5500 Recomposition method downs defined previously O Recomposition method Define which frequency band will be used for the energy calculation of orders C DF constant On constant 0 5 Passband 777 Hz 44 lines DE Cancel When all parameters have been entered click on to launch the calculation of the bandwidth and of the required number of lines for the measurement then validate With Df constant the frequency band used to calculate the order will be a band of constant width Df With Dn constant the frequency band used to calculate the order energy will be a frequency band proportional to the speed and increasing with the frequency Df Dn Speed 60 with the speed in rpm LJ Speedyay pm and Orderya are used to calculate the bandwidth BP The number of lines N is calculated from the bandwidth and the most restricting Df the smallest according to the selected recomposition method keeping in mind that at least 5 FFT lines are required by dBFA in the extraction bandwidth Speed BP pp Efe Me y Orders WE 60 s 9 1 3 Display set up With the post processing order extraction module in dBFA the history of overall levels orders O anda sonogram calculated according to analysis parameters selected
199. re No 1 Mel E function fc ID nom periode imin partial unite File Edt Window Help figure nb size ID t 1 1 nb 2 f 1 1 nb 1 vect_t t 1 periode vect_f imin f 1 surf vect_t vect_f max 10 log10 1D 2e 5 2e 5 0 shading interp rotate3d xlabel Time s ylabel Frequency 1S0 aff sprintf dB s unite aiii zlabel aff Frequency ISO 4 dBID34 BallBreaker dB Pa view 0 90 20 4 Time s title nom 4 6 11 5 Type BARK BAND SPECTRUM Syntax function xxx ID nom fe unite ID identifier of the variable dBID n ID dBFA nom name of the variable ID comment string periode period time step imin index of the min band 1 to 24 unite unit string Note ID is expressed in physical units and in energy Example bark m file on CD ROM function bark ID nom periode imin unite Result nb size ID Figure No 1 mel E3 t 1 1 nb 2 File Edit Window Help f 1 1 nb 1 dBID37 f f 1 imin p vect_t t 1 periode surf vect_t f max ID 0 shading interp rotate3d xlabel Time s ylabel Bark Band aff sprintf s unite zlabel aff view 0 90 title nom Time s PAGE 126 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 11 6 Type NARROW BAND SPECTRUM Syntax function xxx ID nom fe unite ID identifier of the variable dBID n ID dBFA nom name of the variable ID comment string periode period time step
200. ressure gradient and for low frequencies to the microphone spacing the lager the spacer the lower the frequency band accessible With a 12 mm spacer and the convolution correction activated the software the frequency range required by the international standard 50 Hz 6 3 kHz but the user can advantageously perform its sound intensity measurements in two stages A first series of measurements with a 12mm spacer for high frequency bands Then a second series with a 25 mm spacer to cover low frequency bands The field Celerity of sound allows to define the sound velocity in the measurement conditions This value has an influence on the intensity measurement The field Medium density allows to define the medium density in the measurement conditions This value has an influence on the intensity measurement The option adjust to physical frequency limits automatically reduces the pass band to a limit pass band in which the intensity may be calculated correctly After activation this option adjust the limits of the frequency ranges Fmin and Fmax so as they are included in the physical frequency limits With the button Info the user may display the setting criteria of its physical frequency limits and the microphone Space values as well as the residual pressure index of the probe PAGE 147 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Options The option phase correction allows the user to activate the phase correction during a
201. riod 1 2 signal Instantaneous Lin 29 10 02 10 04 24 gt Channel 10 151200 signal Instantaneous Lin 28 0 02 10 04 24 gt Channel 10 151400 signal Instantaneous Lin 29 10 02 10 04 37 gt Channel 10 141200 signal Instantaneous Lin 29 10 02 10 04 37 gt Channel 10 151200 an Instantaneous Lin 28 10 02 10 04 54 gt Channel 02 1 1200 Instantaneous Lin 234002 10 04 54 gt Channel 402 151200 27 17 amp Co hd 01 YN E El Batch DBFA32 gt To do 3 Driver Batch DBFA32 i ioj x Dual signal analysis Y l E an ee 2701 dB Stell ETAT ir ta ml m pire n CMGTCMG CMG1CMG Group by E 2 Q Stage 1 Selection of data items Select with the mouse in the measurement session window all the data items for which a batch analysis will be performed then click on the corresponding icon or use the command Datafile Batches to open the batch processing dialog box L Stage 2 Group data items In the batch dialog box group data items for the analysis By default each item is processed on its own one after another Groups of 1 in between X items However it is possible to group several data items together in order to perform arithmetic operations addition subtraction averaging or to calculate a cross spectrum Q Stage 3 Configuration of the batch processing operations Click on the corresponding icon to display the analysis script configuration dialog box Refer to p
202. rocessing function and allows the user to modify the default name of the operator Default script Signal analysis Default name EOP_MULT_O Activefor Signal Speed profile families Items should belong to the same measurement Result family Global RPM Autospectrum PAGE 131 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 12 4 Calculation of order spectra by TFD Operator OA_DFT From a speed channel and a measurement channel this processing calculates order spectra by discrete Fourier transform OA_DFT_O Calculation of order spectra by TFD Ea Operator Configuration Orders Analysis parameters gt order Tracking parameters gt speed rpm Step 1 Min fi Max fio Step 10 Min 500 Max e000 Speed tracking Order list Strategy Increasing y Order spectrum Block Middle Annuler the Setup tab the following analysis parameters may be defined e Orders Add orders to extract It can be an order list or an order spectrum the list of calculated orders ranges from ist Order to Last order with a Step Order The maximum order allowed depends on the maximum speed studied and on the sampling frequency Orders can be non integer Tracking parameters Define the speed interval between two FFT spectra calculation Input minimum and maximum speed of the analysis e Strategy Indicate if it is a slowdown decreasing or a revving up increasing e Synchr
203. rs see Section 11 2 2 2 O cet display see Section 11 2 3 1 Display speed meter E View signal O Processing of recordings Start processing according to defined parameters F3 Stop processing F4 Display of the speed variation within the defined range Decision Transfer results in a measurement session F7 dr id Discard current results PAGE 166 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 REMOTE CONTROLS AND DBFA It is possible to use remote control objects with 01dB Metravib PC based measurement systems to control the measurement process start data logging run measurements from the sound intensity probe handle etc or to enable a specific event when a user defined condition is fulfilled wait for measurement notify an overload etc The interface between a physical remote control and the measurement system is performed either by the RS232 serial interface of the computer or the digital inputs outputs of the acquisition unit In the measurement software module at the hardware configuration stage a remote control object can be defined We describe in this chapter the generic remote controls of dBFA definition configuration and operating mode Then we present various applications for dBFA remote controls Remotely control the acquisition process for sound intensity and sound power 1509614 measurement with the keys of the probe handle Remotely control the acquisition process with a generi
204. rs of the elements to analyse are set in the dialog box shown below Channel Ch ln i ON s Overall Fax 0000 000 Global At 2 Lint y pu Calculation information NY Tracking resolution fi 0 Ip 2 een Synchro block Middle 4 Automatically put into the session 5 gt i Pass band 1250 Lines number 1601 Cancel Simulate the time rythrn 7 gt Advanced parameters O Definition of the parameters for the sequence of run ups and or coast downs on a speed range to define Speed profile add a run up add a coast down modify the run up or coast down value for the selected item BEBE delete selected item PAGE 162 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Use the Tracking Resolution to define the speed interval between two FFT spectrum calculations The Block synchro parameter is used to assign a FFT spectrum to a speed Either the spectrum is assigned to the speed measured when the data storage for spectrum calculation started Start Or the spectrum is assigned to the speed measured when the said data storage ended End Or the spectrum is assigned to the average speed between the beginning and the end of data storage Middle when the box Automatic transfer to session is checked results are automatically transferred to the measurement session and this to save time when running a series of
205. rum Channel 1 Channel 2 e Check the compatibility of the physical units the type of data Restrictions a i the weighting window frequency and time resolution Family of the result Frequency response function 1 H2 4 6 4 7 Coherence Operator FBCOH This processing produces from the autospectra Gxx and Gyy of the input and output signals and the cross spectrum Gxy between the input and the output the coherence defined by Co Gxy 2 Gxx Gyy The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Frequency response functions Default name FBCOH_0 Autospectrum Channel 1 Autospectrum Channel 2 Cross spectrum Channel 1 Channel 2 Check the compatibility of the physical units the type of data the weighting window frequency and time resolution Family of the result Restrictions PAGE 103 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 5 Arithmetic operations These operators allow the user to add subtract or average signal data spectra and overall quantities For complex spectra cross spectrum transfer function coherence only the averaging operator is available These operations can be performed according to two types of arithmetic rules Algebraic rule For energy summation spectra overall quantities 40 dB 40 dB 80 dB For amplitude summation signal 40 dB 40 dB 8
206. s for more details on each Tonality 0 00 tu psychoacoustic criterion asper a Sensory Pleasing Sound 0 00 pu Articulation Index Rooms 5 00 Ej The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name PSYCHO_0 Signal impulse response Activefor Apply only for one item Family of the result PAGE 113 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 7 4 Specific Loudness Operator BARK This analysis results in a Bark band specific Loudness with time history capability specific Loudness multispectrum a time step lt 50 ms is required for later psychoacoustic criteria computation The result is expressed in sones according to Zwicker B The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined BARK_0 Specific Loudness Operator Configuration Notification Bark bands Miri z0 100 Hz Max 24 12000 15500 Hz Bark bands Gives the minimum and maximum Bark bands used for computation of the overall Loudness level wv Multispectra jo fa m An indication of the frequency range covered by the analysis for any given Bark band is given C Diffuse Multispectra If this option is activated the user obtains the time history of the spectrum over the item duration The time step may vary
207. sducer is a pressure microphone the view meter displays the values in Pascals Pa In case the transducer is an accelerometer the view meter displays the values in m s 2 The levels are calculated from international system units SI It is possible to modify the default values with the command Preferences Units management see Section 19 1 PAGE 150 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A E Trigger Define here the trigger parameters used for acquisition Trigger selection Direct to start the measurement immediately after clicking on the start acquisition command or Threshold to start the acquisition with a threshold condition negative or positive defined on the right hand side The programme waits for the threshold when the measurement start command is activated Trigger delay in ms For threshold triggering it is possible to start the acquisition with a pre delay or a post delay in relation to threshold crossing Input this delay or use the arrows up down to increase reduce the value Operation Select a logical Boolean operator for the threshold trigger OR to activate the recording if one of the conditions is fulfilled and AND to activate the recording when all conditions are fulfilled PAGE 151 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 3 Display configuration All these functions are accessible from the horizontal toolbar of the measurement window 8 3 1 Curves to display Use the command Displ
208. se the command EX General calculation server to launch the calculation server allowing the user to define and execute post processing analyses The following user interface is displayed on screen 1 List of scripts this list shows all analysis scripts that are compatible with the data items selected in the measurement session datafile According to the status of the calculation server analysis in progress waiting and pause and the user actions stop analysis activate an analysis these scripts are accessible for edition and configuration 2 Pilot measurement session the title of the window indicates which document measurement session or a batch is currently controlling the calculation When selecting items in a measurement session or in a batch the calculation server gives only access to the analysis scripts that are compatible with the data items to analyse The user may then select a script by selecting it in the list 3 Status bar this zone shows when a script is being executed the name of the active operator as well as the ID of the data item currently being analysed 4 Configuration of a script click on this key to display the script configuration dialog box see paragraph 4 3 5 Duplication click on this key to duplicate a default script of the application software in order to rename it to select different operators or to change analysis parameters For example the application software may offer only one script
209. se the command Units management under the Preferences menu The following dialog box appears on screen Quantity type Acceleration dBFA allows to define default units and references used for each type of metrics Also it is possible to define export and copy paste units for spectra and overall levels either physical units or dB Click on modify to edit the physical unit and or the reference value of the selected quantity in the list as well as the export unit Click on IS values to select the values of the International system as standard This function cannot be accessed when a measurement is running Close the measurement window to edit the references values and the units Let us consider an example of conversion For pressure type transducers the reference value of the SI system is 2 10 Pa The sound pressure level is given by the formula Lp 10 log p2 po2 where po is the reference value Therefore for an acoustic pressure level of 2 10 Pa dBFA will use a reference of pyp 2 10 Pa to calculate a sound pressure level of 60 dB that is 10 log 2 10 2 2 10 2 If one define a reference level of p0 2 10 Pa the sound pressure level displayed in dBFA will be equal to 80 dB Likewise it will be possible to edit these parameters for each type of transducer depending on the application PAGE 185 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 7 Editing of the software licence nu
210. ser to browse the hard disk in order to find a specific folder Root Index Select the root number for audio event exportation The type of the exported audio records will be root_index_number MAT 4 Save he result Annuler In the example above the first record will be name 01db_wave_12 MAT then 01db_wave_13 MAT etc If a directory already contents exported records select an index number higher than the maximum existing index in order to avoid overwriting records If using this operator in batch mode the selection number of the item will be indicated in the file name The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name MATLAB_0 Activefor _ ili Signal families Restrictions none Family of the result x PAGE 116 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 8 2 Export to 01dB Metravib WAV format Operator WAVO1DB This processing exports the input quantity at the WAV 01dB Metravib format WAV file Windows compatible The following dialog box appears on screen WAVYO1DB_0 Export at 01dB WAY format Operator Configuration Notification Export directory p co windowe temp Hoot Index a dB_wawe_ fi 2 Save the result Annuler In the Configuration tab the following analysis parameters may be defined Export directory Select a folder on the comp
211. sing neuronal network automatism etc A link in dBFA using the DCOM protocol allows the user to use MALAB as ActiveX server automation server That enables sending data items of a dBFA measurement session in the MATLAB workspace to use the specific display and or processing functions After having transmitted the data to MATLAB the user has also the possibility to restore these data in dBFA and to modify them as a new item 4 6 11 1 Use of Communication matlab operator A dedicated script integrates this operator When selecting an item ALO x which is MALTLAB operator compatible the screen indicates the following dialogue box Note the MATLAB communication script can group together AI 01 dB Stel several communication operators activated in parallel that works on No e linde the same inputs batches In the following are the types compatible at the moment e Type SIGNAL Signals impulse response static measurements tachometric etc e Type GLOBAL Short Leg history of the psycho acoustic parameters etc e Type Narrow band spectrum Narrow band real and complex spectra e Type Broad band spectrum Fractional octave spectrum 1 1 to 1 48 octave e Type Bark band spectrum Sound intensity bark spectra The script edition proposes the following interface MATCO_0 MATLAB transfer Operator Configuration Notification The command files in m format are familiar for all MATLAB users Directory g
212. st table the selected data items Save the active measurement session file CTRL S ch Playback the selected signal recordings Modify a data item date level correction etc session Display an information window about the measurement zl Edit the general comment of the measurement session T Delete the selected items Launch the operation server off line analysis x Start a batch processing analysis See chapter 4 See chapter 5 s S ll S le 1 elo Display a window to create a test report Open the index on the on line help system Display a multispectrum sonagram 1 Shortcut for predefined operator script All items date type My Sort data items according Fil Automatically adjust the width of each column to the selected request Edit requests Automatically adjust the size of the measurement session window Select the window columns to display PAGE 22 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 2 2 Measurement session information window il Comments Use the command LE General Session Information to display the information el e window of the active measurement session Date of creation 27 01 99 17 10 18 Sie ais a ai The following information is given in this window Version 1 001 Total number of iterns 90 Size bytes 30228374 E ue ae St eaten Date of creation and last modification Ji Sa 16 41 16 Number of data items contained in the datafile isto RT 1 E Datafile size Autospectru
213. t gt gt These are text files which integrate a function that can be called PETER directly from the MATLAB command window z Required command rn file MaVisuPourdudiod The 01dB Metravib operator does the same it proposes to the user to call a file function normally the same name with a list of fixed and pre defined parameters that the MATLAB user has to respect Save the result Annuler The standard m files are on the installation CD ROM of 01dB Metravib programs audio m for signal type items leq m for global type items fb m for narrow band spectrum type items fc m for broad band spectrum type items bark m for bark band spectrum type items Copy the m files in a directory on your hard disk if using the MATLAB operator Then enter the directory path in the Working directory field of the dialogue box below PAGE 122 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Let us consider the m file below for example function MaVisuPourAudios ID nom fe unite figure nb size ID t 1 1 nb 1 vect_t t fe plot vect_t real ID xlabel Time ylabel unite title nom With this file we display a SIGNAL type item of dBFA The activation of a script displays the MATLAB visualisation below in dBFA for example u dBFa32 Cmg Exemple CMG e x Fichier Edition Acquisition G n ral Campagne Pr f rence Fen tre Olea i fea 2 an Exemple CMG Fen
214. t only one type of general request is defined in dBFA All items Sort data items of a measurement session PAGE 49 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 6 2 Add or modify a request local or global 3 6 2 1 Overview Access the dialog box shown below when creating a new request or editing an existing request Give a name to Navigate displacement removal of the conditions of a request Definition of a request the request N Name Signal Channel 2 30s to 1 minj Conditions 2 JT t l CR AND lat ae channel no AND Duration List of conditions AND Duration that compose the Statistical results request T OPERE After definition of the request name that will appear in the list of requests define one or several conditions that compose the request The columns of the list of conditions of a request allows the user to define the following parameters Logic column Define a Boolean operator AND OR when several conditions have been defined The data items will be displayed when all the conditions of the request are verified operators AND or at least one condition is verified operators OR NEG column negative If this case is activated the data items that will be displayed are the items that do not correspond to the condition Fields column Select the quantity according to which the data items will be sorted A list proposes all the fields that characterise data items family name ID d
215. t each one of them to define the calculation parameters To do so select the adequate operator in the list and press the Edit key PAGE 64 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 4 Using shortcuts to run scripts The dBFA interface allows to launch operator scripts directly from the shortcut buttons in the session main toolbar Each of the six buttons can be assigned to a predefined script in the calculation server File Edit Acquisition Analysis General Datafile Preferences Window sae Ojal il El MB ks e 4 2 1 E jajaj The calculation server will display the shortcut number next to the script name as shown opposite Driver Ap ES FFT 0000H2 801 lt 1 gt 13 Octaye 22 gt D7 SiO maana MATLAB communicator Export pi a Sel 1 Family Datatype W Date locati 1 O Signal Instantaneous Lin 3070 02 11 41 24 Surpr 1 Signal Instantaneous Lin 3070 02 11 41 24 Surpr 4 4 1 Assigning shortcuts O use EX or General Calculation server use to consult all scripts in the server and not only those corresponding to the selection in the measurement session select a calculation script in the pop up list need be using EM O Select the shortcut number on the pop up list on the right and change the settings if 173 Octave lt 2 gt a The corresponding shortcut button becomes active in the toolbar aae Ea ay FA No Operation in pr
216. t one or several data items in the list and use the command ra Datafile Modify to edit general parameters of these items The user may modify the following parameters for each item The start date and time The location and comment defined during acquisition The study zone of the item Furthermore it is possible to apply a calibration correction level in dB for some given types of data items For Signal items an Information tab is available For autospectra resulting from building acoustics measurements the measurement channel can be assigned a type Each item is identified in the measurement session by its identifier ID This identifier is a number To simplify the processing of measurement sessions location comments and date of the elements of a session can be entered directly by clicking on the appropriate files when the element is selected 3 2 6 1 Editing of items date and time In the Date tab edit the date and time values corresponding to Sie acquisition start for the selected data items 0912 1998 13 30 20 340 ke The modification can be performed in an absolute manner direct e Bring forward editing of the date and time or by bringing forward or putting back fono 01 200 000 E the original date by a user defined duration format Day hour minutes seconds milliseconds The user has to confirm each date and time modification 3 2 6 2 Editing of items location and comments Modification of 69
217. t vect_f angle ID 180 3 1415 xlabel Frequency Hz 0 02 04 06 pe 2 44 15 18 z ylabel Phase ENOS x10 Phase PAGE 127 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 11 8 Import Matlab results in dBFA The MATLAB communication operator is also used to import MATLAB data in dBFA Therefor it is enough to modify the audio file m called reverse m as follows function ret reverse ID nom fe unite nb size ID global dBResult dBResult ID nb 1 1 1 ret 1 Required modifications The function has now a return variable ret The function defines in its code a global variable called dBResult fixed name A test will be carried out on the return value of the function after the start of the MATLAB reverse function The MATLAB operator import automatically a variable called dBResult as an item in the measurement session CONSTRAINT dBResult has to have the same dimension as the ID input fa dBFa32 CMG1 Al ES Fichier Edition Acquisition G n ral Etude Pr f rence Fen tre This one allows the user to dedicate olea Li 2 ial AIP treatments in MATLAB that are not proposed in dBFA The Reverse function is used to get the mirror Gh eee uP PEE Bureau 0148 gt Voie 1 hor 1751200 of a signal for example 1 1 Audio Instantan Lin dBResult 03 11 99 17 26 53 Bureau 01dB gt Voie 1 10 000 1 51200 1 i The name of the new item is dBResult and it has the path of the operator Pals X
218. the following analysis parameters may be defined xi Operator Setup Filter order Define the filtering order a high order can yield better results Filter order 20 F Number of lines Enter the number of lines that will define ines number 256 the frequency resolution Sliding window ii 0 mz Sliding window Define the length of the time block to Time analyse Time step jo A 20 me gt Pointto point Y Time Define the timing for the multispectra in milliseconds or sample by sample by checking the Point by point option depends on the sampling frequency Save the result Annuler The Operator tab provides a detailed description of this type of processing and offers the possibility to modify its name Default script Signal analysis Default name CAPON_0 Signal family Applies for one item only Result family Autospectrum PAGE 79 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 Operations on Signal data There are several types of operations that can be performed Selective digital filtering or frequency weightings The digital filters used by 01dB Metravib are recursive filters based on elementary Butterworth cells of order 2 ensuring a great stability over the frequency range Time windowing by a pre defined window E Signal processing Resampling undersampling gain denoising convolution envelope Integration and derivation 4 6 2 1 Low pass filtering Operator LOW
219. the next time the program is used Access Calibration via the Set up menu 2 Model ve e The input gain and transducer sensitivity may be TENER calibrated from the control panel Values may be modified Model GRAS using the and Adjust buttons si Calibration levels can be expressed either in dB or in pprove o Factory sensitivity 5 000e 02 WiPa physical units Current sensitivity 5 000e 02 WiPa Conrected sensitivity 1101802 WPa On validation the system is ready to carry out calibrated dB Physical measurements Cancel Before calibration Verify that the calibration signal remains constant for a sufficiently long period Verify that the gain view meter is correctly positioned no underload no overload It is preferable to place the calibrator on foam to reduce the effect of vibrations e After calibration If for the same transducer calibrator pair the sensitivity after calibration differs greatly from the original sensitivity damage to the microphone may have occurred If the measured values are not correct but the calibration value is OK it could mean that the sensitivity of the microphone is correct only at 1 000 Hz Check the microphone membrane PAGE 141 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A A microphone is very fragile equipment A fall of 10 cm may damage the microphone membrane As general rule if the measured value in dB varies by 1 5 dB from the
220. the original bandwidth e g 1 6 octave spectrum recombine into an octave spectrum Family of the result Autospectrum Intensity active free field reactive PAGE 96 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 3 3 Time recomposition Operator RECOMPT This processing allows the user to recombine a broad band or narrow band multispectrum either on a larger time basis multiple of the initial time basis or to calculate the minimum maximum average spectrum from the multispectrum on the same different time basis or on a different one The recomposition on a different time basis affects the minimum and the maximum extraction Alternatively to extract an instantaneous spectrum the overall level of which meets user defined criteria from the multispectrum and on a different time basis or not The following dialog box appears on screen In the Configuration tab the following analysis parameters may be defined RECOMPT_0 Time recomposition Operator Configuration Notification HMultizpectrum time basis Identical fe pos 5 me C Recombine the original multispectrum Extract the spectrum from the multispectrum For which each frequency corresponde to Average For which the weighted overall level is Maximum Lin i Save the result Multispectrum time basis Select the multispectrum time basis identical or multiple of the Original
221. this way a relationship between the dB scale and sones may be established for 1 kHz For the other frequencies the sound level and frequency are altered to give the same feeling of Loudness This method may appear user dependent however studies have shown considerable independence of this factor from the results The resulting Isosone graphs are made up of points corresponding to frequency levels that have equal Loudness obtained from pure sounds O Fluctuation Strength The fluctuation strength concerns the sound models for frequencies fmoa perceived to be less than 20 Hz The unit of Fluctuation strength is the vacil E Sharpness The Sharpness of a sound describes the level of acuteness It behaves in part as a barycentre weighting of the Bark band spectra It is expressed in acum PAGE 111 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A E Tonality It allows to quantify tonal components in a spectrum of a signal by comparison of the Loudness level due to these components and the overall Loudness E Roughness The Roughness criterion is used to identify the perturbing effect of mid frequency modulation It is expressed in Asper It deals with sound level modulated in the range 20 Hz 300 Hz UU Unbiased Annoyance UBA All the previous parameters give an indication on the nature of the noise and its perception by human experience However it would be interesting to be able to obtain a general description Zwicker proposed a new par
222. time basis in order to recombine the multispectrum or extract a spectrum Two possibilities are then offered to the user Recombine the original multispectrum Select this option to recombine the original multispectrum according to a different time basis multiple of the original time basis The result of the analysis is a narrow band or broad band multispectrum of greater time basis Extract a spectrum from a multispectrum Select this option to extract a spectrum from the multispectrum The user may extract the following spectra The average minimum or maximum spectrum for which each frequency correspond respectively to the average minimum or maximum values of the multispectrum from the multispectrum and on a previously defined time basis The instantaneous spectrum for which the overall level is either the maximum or the minimum A B C or Lin weighted level of the multispectrum from the multispectrum and on a previously defined time basis The multispectrum time basis for the recombination must greater and a multiple of the original time basis LJ Extracting spectra can be done on a multispectrum with a different time basis as well The time basis of the multispectrum will therefore greatly influence the result The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default name RECOMPT_0 Autospectrum Intensity active free field
223. ting Operator WEIWB WEIWC WEIWD WEIWE WEIWF WEIWG WEIWJ WEIWK WEIWBC This analysis results in a vibratory weighted time signal The filter used requirements of standard ISO 8041 Available weighting are Wb Wc Wd We Wf Wg Wh Wj Wk and Wbc The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name WEIWB_0 WEIWC_0 WEIWD_0 WEIWE_0 WEIWF_O WEIWG_0 WEIWJ_0 WEIWK_0 WEIWBC_0 Activefor Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families 4 6 2 10 KB weighting WEIWKB This analysis results in an KB weighted time signal The filter used requirements of standard DIN 45669 1 1995 06 and equivalent The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name WEIWKB_O Activefor Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families PAGE 85 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 11 Windowing Operator WIN This processing allows the user to apply a user defined time weighting window on a time signal using segments of classical windows Rectangular Kaiser Bessel Flat Top etc zeros signal set to 0
224. tion and Analysis of Test Data Select one or more items in a measurement session list use the command File Export and Lexade LXD to export data at Lexade format 3 7 8 Exporting data in ME scope format Modal analysis software Select one item in a measurement session list use the command File Export and ME scope BLK to export data at ME scope format modal analysis software 3 7 9 Exporting data in MATLAB format Select one or more items in a measurement session list use the command File Export and MATLAB MAT to export data at MATLAB format directly loadable from MATLAB software by load command PAGE 58 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 7 10 Customisation of dBFA The software allows the user to customise various parameters for displaying the data The commands Preferences Colours allows the user to respectively set the colours of the different types of data displayed on screen Select in this list the type of data for which you want to modify the colour The actual colour associated to this type of data is displayed next to the list Then select with the mouse the new colour in the bottom part of the dialog box Click on OK when all the modifications have been carried out Font Ei ES Font Font style arial Regular 10 Cancel The command Preferences Font allows the user Arial Alternative e Fr Arial Alternative Symbe Bold i Arial Black Bold Italic 11 to choose
225. to compute commonly used room acoustics criteria reverberation Time Clarity STI etc is available in the dBBATI32 software package 4 6 10 1 Echogram Operator ECHOG This analysis results in an octave or third octave echogram The following dialog box appears on screen ECHOG_O Echogram f i In the Configuration tab the following analysis parameters may Operator Configuration Notification be defined Bandwidth to define the spectrum bandwidth for the analysis octave 1 3 octave bands Frequencies Band width Min Hz Max Hz 143 octave 50 jok Full octaves Min Minimum centre frequency of analysis in Hz Max Maximum centre frequency of analysis in Hz Full octaves If this option is activated the software will set the minimum and maximum frequency limits so that only full octaves are calculated Save the result Annuler The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Default name ECHOG_O O Z o S O Signal Impulse Response Apply only to one item Family of the result Autospectrum PAGE 121 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 11 MATLAB connection operator MATCO The MATLAB software holds today a leader position in scientific operating software thanks to its many tool boxes dedicated to very specialised domains like signal processing image proces
226. uired in dBFA Stop command 3 10 1 5 Operating process Once a remote control object has been completely configured and if required once triggering parameters have been defined in the application software the operator may use the remote control The operating process is very simple Simply connect the physical remote control to the communication interface that was selected When the triggering conditions are fulfilled or when the user clicks on a button the physical remote control or the software executes the actions defined Consult the examples for more information on the use of the remote controls If you wish to develop a physical remote control for specific needs do not hesitate to contact your 01dB Metravib representative to discuss your application Consult the connection diagrams of the communication interface as well PAGE 172 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 10 2 Description of dBCD32 INI The dBCD32 INI file contains information relative to the definition of remote control objects used in 01dB Metravib measurement software programs The syntax in the file is as follow Com Device Count 4 It is the number of remote control objects defined in the file They are numbered in this example from 0 to 3 therefore a total of 4 objects This number is incremented each type a new remote control object is defined CDEV 0 Type 1 This is the type of remote control Type 1 define a generic 2 inputs 2 o
227. unction and allows the user to modify the default name of the operator Annuler Default script Signal analysis Default name DECIMO eC SCSCSCSCSC sCTS Signal Impulse Response families Applies for one item only Family of the result Signal Impulse Response families PAGE 88 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 15 Denoising operator DENOIS This processing is used to clean the signal and improve the signal to noise ratio The dialog box below is displayed on screen In the Configuration tab the following analysis parameters may be defined x Wavelet and Parameters 1 and 2 Select the wavelet family Operator Setup and its parameters The wavelet shape is displayed in the view ee Peeters Palemeterz below and should be as close as possible to the signal shape Symmlet fi Analysis window Block size in number of points on which Keeping each decomposition will be performed and on which denoising will 50 z be carried out over time Decomposition level The wavelet decomposition performs a Ateo IBA multi scale analysis by a two fold undersampling at each foz la x decomposition step By analogy with a filter bench this means that with an analysis window of size 1024 two mirror low pass and high pass filters will be used to generate two daughter wavelets of 512 points and then the same procedure be carried out again on M Save the resul Annuler daughter
228. untain PAGE 31 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 3 Narrow band spectra and or multispectra transfer functions and coherence This type of view is used to graphically display autospectra and cross spectra in narrow bands with multispectrum capability as well as transfer functions and coherence For multispectra a spectrum calculated for each integration step defined by the user a scrolling bar at the bottom of the view is shown in order to view the spectral quantity at different time periods Calculation of harmonic cursors and maxima is not possible on a multispectrum An example of this type of view is given below Definition of display parameters cursor synchronisation multiple cursor displays and of Dx and Dy information when displaying 2 cursors __ Graphe spectre CMG d loj x elel E e Fr afoul E Display of overall ID 3 Moyenne G1 Hz dB 2 000e 05 Pa PWR MN EEE levels de 10510 IN OR CEY B ph feo 8 Bd amp Deltax 525 00 DeltaY ID 5 3 3 DeltaY ID 9 2 3 Display of spectra P Too ANI O D SN ee ID 5 61_ gt Voie 1 Hz dB 2 000e 05 Pa PWR EMMI RIG SERA A transfer functions MO A S etc on the same graphic view EEUNA tt aaa ath a 0 2000 4000 6000 s000 10000 12000 14000 16000 18000 20000 Lint Ect 15 03 02 18 38 06 375 06375 Scroll bar for a multispectrum view with timer The toolbar of the graphical view allows the user to perform the following
229. uration etc Op column operation Equality inequality of the quantity selected in the Fields column Value column Value that takes the quantity selected in the Fields column The operation of the Op column forms the condition of the request Furthermore a tool bar allows the user to perform the following operations Insert a condition in the list at the current mouse location T Remove the condition selected in the list Move up the condition selected in the list Move down the condition selected highlighted in the appears in video inverse list PAGE 50 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A The definition order of the conditions is important indeed the Boolean operator logic column of the last condition defined is applied to all the conditions that precede it For example for a set of conditions to verify simultaneously AND operator in between each condition if the operator for the last condition is OR then the request will display data items that match all the conditions associated by the AND operator as well as the data items that match the last condition The example below illustrates the principle Logic NEG Fields Value Logic NEG Fields O Value a AA Signal AND Curation OhO1 m00s000 AND Duration Oh mU0s000 AND Duration gt Ohd0m 308000 OR Duration gt Oh00m 30000 Data items of the Signal family and of duration greater than 30 seconds will be displayed as well
230. urr 2 M Orientation O Pages from fi to gil ci Portrait Selection C Paysage Disposition fi en un y MM impime les bordures A4 210 x 297 mm Format du papier NUM 2 Access directly to the printer configuration dialog box by the command File Print Setup and to a preview of the document to print by the command File Print Preview The toolbar of the print preview window allows the user for example to zoom in the preview document Graphic print out Left margin mm fi 5 Upper margin mm o width mm reo a Height mm EJ a Cancel When printing graphics the user can set a few additional parameters by the commands Preferences Print options The user can set the margins of the graphic printout frame To print a set of graphs select the elements to print in the measurement session and go to File Print selection Graphs will be printed using the default printing parameters PAGE 55 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 7 2 Exporting data to a word processing or spreadsheet software Results can be exported either as images graphs and data tables or as actual values using Edit Copy CTRL C Then paste Edit Paste the data into a word or spreadsheet process To obtain frequency values in digital format after broad band spectra export add in dBFA ini file the following heading Export LabelFreqNum 1 If LabelFrqNum 0 frequency values
231. uter hard disk for storing the audio events that have been exported MAT files The key 7 allows the user to browse the hard disk in order to find a specific folder E Root Index Select the root number for audio event exportation The type of the exported audio records will be root_index_number WAV In the example above the first record will be name 01db_wave_12 WAV then 01db_wave_13 WAV etc Ifa directory already contains exported records select an index number higher than the maximal existing one in order to avoid overwriting records If using this operator in batch mode the selection number of the item will be indicated in the file name The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Export _ Default name WAV01DB_0 Signal families None Family of the result x PAGE 117 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 8 3 Export to MP3 format operator MP3 This operation is used to export signal items in MPEG Layer III MP3 format which allows for data compression with no loss of quality during playback The exported signal selected in a measurement session must be sampled at 32 kHz or 41 kHz To export a signal sampled with a different frequency use the resampling operator see Section 14 6 2 10 before to obtain compatible signals Use the dialog box below to perform the exportation
232. ution in order or in frequency Order filtering This process uses an order tracking time filter from a tachometric channel Filter characteristics min max order as well as tracking FIO_0 timing are user selected Cycle defects This process characterises cycle defects with respect to a ACY_0 reference tachometric channel This operator performs an order extraction from a Signal item and _ One Signal a Tacho item resulting from the recording of a tachometric item and one Order Phase extraction transducer on a dynamic channel This operation yields Speed profile OAF_0 A multispectrum versus speed containing phase information An overall level per extracted order versus speed An item containing information on the phase per extracted o This processing carries out from a speed profile channel and a measurement channel the order extraction with method choice constant resolution in order or in frequency The extraction is performed by successive levels for stabilized values of the speed TACHOMETRY Order extraction by successive levels EOP_MULT_0 Calculation of order spectra by TFD OA_DFT_0 From a speed channel and a measurement channel this processing calculates order spectra by discrete Fourier transform Recomposition of a broad band or narrow band multispectrum into a multispectrum of different frequency bandwidth including Loudness bark Frequency recomposition RECOMPF_0 Recombination a broad ban
233. utputs remote control Name generic 2 inputs 2 outputs Comm 1 Clign 500 Flash 1000 Appui 1000 DbICIk 200 These parameters are defined in the configuration of the remote control name communication port and duration parameters See paragraph 10 1 2 Fct CIkO 0 Fct DbICIkO 0 Fct Appui0 0 Fct Ciki 0 Fct DbICIki 0 Fct Appui1 0 These parameters are defined in the configuration of the input contacts associated to an input message See paragraph 10 1 3 The number corresponds to one of the 32 input messages It varies between O not used and 32 stop function 16 Outi_9 2 Out2_9 2 Outi_10 1 Out2_10 1 Outi_15 2 Out2_15 1 Outi_1l6 1 Out2_16 1 Outi_17 2 Out2_17 1 Outi_18 1 Out2_18 1 These parameters are defined in the configuration of the output contacts See paragraph 10 1 4 A state of an output contact is associated with this output messages The number corresponds to one of the 32 output messages It varies between 0 not used and 32 stop command 16 CDEV 1 Type 7 Name G R A S automatic calibration Comm 1 This specific remote control is used to activate an electrostatic actuator of GRAS outdoors permanent microphone units 41AM CM in dBTRIG32 CDEV 2 Type 2 Name G R A S sound intensity probe Comm 1 Clign 500 Flash 200 Appui 1000 This specific remote control is used to control measurements of sound intensity and sound power in dBFA from the handle of a GRAS sound intensity probe 50AlI
234. value that would be measured with the microphone according to the original sensitivity see calibration data sheet consider your microphone as faulty Example For a microphone that as a factory sensitivity of 50 mV Pa and a calibrator that delivers 94 dB at 1000 Hz The microphone is able to perform correct measurements If The measured calibration level lies between 92 5 dB and 95 5 dB The current microphone sensitivity lies between around 40 mV Pa and 60 mV Pa multiply or divide the original value by a factor of 1 1885 For greater or lower microphone sensitivities consider the microphone as faulty Return it to your 01dB Metravib agent PAGE 142 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 8 INTENSITY MODE dBFA can be used to perform real time acquisition of autospectra and cross spectra in narrow bands first and second FFT passes as well as sound intensity and averaged sound pressure cross spectra in octave or third octave bands by FFT analysis The characteristics of a sound intensity probe microphone spacing etc can be defined by the user to perform sound intensity measurements acquisition of the active sound intensity level Li the reactive sound intensity level Lj and the free filed sound intensity level SIL All the measured quantities can be displayed in narrow bands for each FFT pass or in octaves and third octave bands recomposition from the FFT analyses The cross spectra in narrow bands can be
235. velope C Signal phase The resulting signal is sometimes called a phase quadrature signal as applying a Hilbert transform is equivalent to adding 1 2 to the phase for positive frequencies and subtracting 1 2 for negative frequencies Thus the transform of cos 2x x fO x t is sin 2z x f0 x t Save the result Annuler Analytical signal Signal envelope and analytical signal phase The analytical signal of a time signal x t is a complex signal the real part of which is x t and the imaginary part is the Hilbert transform of x t The envelope x t is obtained by taking into account the module of this signal The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Envelope gt O Default name ENV_O 1 Signal item Applies for 1 item only Result family 4 6 2 17 Calculation of KB t and KBFm t signals This processing calculates 3 items KBF t signal KBFTm t signal and max speed Vmax during measurement duration The calculation used requirements of standard DIN 45669 1 1995 06 The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name KB 0 Activefor 1 Signalitem O S Applies for 1 item only Result family ETE PAGE 90 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 18 Operator Puls
236. wavelets to the 9 level maximum Conservation Select the percentage for energy saving An energy thresholding is performed on the lowest level daughter wavelets by selecting only a defined percentage of wavelet coefficient The lower energy components corresponding to the noise are thus deleted The original Signal is then rebuilt by applying reverse filters and interpolating thus yielding a signal including only the higher energy components The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name Activefor Signal Impulse response families Apply to one item only Results family Signal Impulse Response PAGE 89 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 4 6 2 16 Envelope operator This processing calculates either the signal envelope or the analytical signal phase or its Hilbert transform In the Configuration tab the following analysis parameters may be defined ENY_0 Envelope g x Operator Configuration Hilbert transform The Hilbert transform of the spectrum signal X f consists in building the spectrum signal X f with Xx 1 3 sgn f Performing a FFT on the original signal then this operation and then a reverse FFT yields a time signal which is the Hilbert transform of the original signal Calculation selection f Hilbert transform Signal en
237. which computer font will be used to F Arial Narrow 12 display text in dBFA Arial Rounded MT Bok 14 F Aurora BdCn BT hd E xl Select the font type style regular Italic Bold etc and size in this dialog box Sample AaBb yz Script Click on OK when all the modifications have been carried out western 3 7 11 Measurement session general options Setup ES Use the Preferences Measurement session command to define general we Canin ota parameters about the management of measurement session datafiles M Confime add items The Confirm delete items option allows the user to display a dialog box to confirm or not any item removal operation in the active measurement session datafile Save items in separated files Cancel The Confirm add items option allows the user to display a dialog box to confirm or not any item addition in the active measurement session datafile The save items in separated files option allows the user to save the different items of a measurement session files into binary files The binary data of each item are stored in a BID Binary Item Data file and the references of this item are saved into the measurement session itself The save automatically every X minutes option is used to regularly save measurement sessions PAGE 59 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A Two techniques of storage are available in the software dBFA storage in separate files or storage grou
238. will be displayed in the main window of a measurement session data file The dialog box shown below appears on screen Columns displayed x Select with the mouse the different column fields that will be displayed in the main window of a measurement session data file Selected elements Family Type Data type Select all Unpick all The key Select all allows the user to select all possible columns fields while the key Unpick all allows the user to clear all the column fields Cancel The table below gives the meaning of column available in a measurement session window Columns Meaning When selecting several data items in the measurement session window a number is shown in this column SELECHON SEN that displays the selection order of the data items Identifier of the data item A number This number is incremented from 0 each time a data item is added to the measurement session Family Set of data items of the same family audio autospectra transfer functions etc Type Type of a given spectrum emitted noise received noise etc for building acoustics Type of quantity allowing us to define more accurately the data item for a Fast sound pressure level the pata type family would be Leq and the data type will be Fast Frequency weighting applied to the data item during acquisition or off line analysis A B C Lin weightings vibration weightings etc Name of the analysis that created th
239. x Djelal 10 l esal xz 2 Allitems date type Sel Sel 4 90 S ID Family Datatype Wei Name 25 11 94 15 53 07 2a 154 16 g2 se 19 12 98 ERE 09 12 98 13 37 33 09 1 288 13 37 33 oie 2 0760 A rt Ready P NUM 2 Display of data items contained in the datafile as for a database In the measurement session window the data items are displayed as for a database Each line corresponds to a given type of data audio event spectrum etc and each column corresponds to a given type of information about this data item name weighting frequency or time resolution etc The horizontal toolbar allows the user to perform general and data processing operations for the data items contained in the measurement session Select data items in the list and perform the desired operation Items can be duplicated by using the keypad CTRL C CTRL V In this case the data are also copied to the clipboard for external use For a single duplication in dBFA prefer the keypad SHIFT CTRL C CRTL V This will prevent from using memory resources of your computer 3 2 1 Toolbars The following operations are possible for the data items contained in a measurement session file According to the type and number of items selected in the list some operations may not be activated Create an empty measurement session file CTRL N us Plot graphics the selected data items Open an existing measurement session file CTRL O Li
240. x appears on screen In the Configuration tab the following analysis parameters may be defined PAS5_0 Band pass filtering Low cut off frequency define the low cut off frequency in Hz Operator Configuration Notification Low cut off frequency Hz 07 1 1 High cut off frequency define the high cut off frequency in High cut off frequency Hz 414 21 Hz Filter order 20 r Filter order Select the Butterworth filter order between the Slope dB per octave 120 following values 2 4 6 8 10 12 14 16 18 20 22 24 26 28 and 30 The filter order defines the octave fall off rate dB octave and therefore the effectiveness of the filter The greater the filter order the greater the attenuation of low and high frequency bands I Save the result Annuler Band pass filters remove components whose frequency is lower than the specified low cut off frequency and greater than the high cut off frequency with an octave fall off rate dB octave depending on the filter order It corresponds to a low pass filter and a high pass filter simultaneously The Operator tab gives an overview of this type of processing function and allows the user to modify the default name of the operator Default script Signal analysis Default name PASS_O Activefor Signal Impulse Response families Only applies for one item Family of the result Signal Impulse Response families PAGE 82 DBFA SUITE
241. y 01dB Metravib systems can be stored as items of a measurement session data file Signal recordings Impulse responses acquired by MLS technique Time histories of overall quantities Overall levels frequency and time weighted civil aviation criteria PNL PNLT psychoacoustic criteria Loudness Sharpness etc spectral time history Autospectra and cross spectra in real or complex narrow bands time averaged or not computed in real time or off line Broad band spectra from octave to 1 48 octave resolution computed in real time or off line Bark band spectra specific Loudness Transfer functions cross spectra coherence etc Noise source codes Measurement chain information dynamic range selection overload etc Comments Table of results psychoacoustics Histograms Echograms Room acoustic criteria a etc The container therefore has a database structure well adapted to handle batch processing for example PAGE 184 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 11 6 Conversion units and references management from a physical unit to a dB level Definition of default units and references E Quantity Type Unit Reference ollas F Global units and referencces X Pressure 000e 05 Pa Acceleration 1 000e 06 mits i 1 000e 03 ms Physical unit 1 000e 1 2 m 1 000e 06 H Reference li e 006 m oe 1 000e 03 m s 1 0006 06 Pa 5 1 values Cancel Modify Cancel U
242. ype tab select the type of a given autospectrum for building Selection acoustics calculations Type signal M Building type 1 Signal None 2 C Speed profil A Emitted noise l rene Received airbome noise C Background noise Impulse Impact noise BE C Received impact noise C Correction Annuler 3 2 6 6 Information e DAC conversion value Conversion value to go directly from the digital value of the acquisition card to the analogue value in Pa This value depends on the transducer sensitivity and on the gain Example For the SYMPHONIE acquisition platform the sampling is performed on 16 bits i e on values ranging from 32768 to 32768 For a value of 5000 the level in m s is 5000 x DAC i e 5000 x 3 432 4 1 716 m s Modification of 0 1 2 test cmg E Full le l uli Scale leve Date Location Comment Calibration Study Type Informations a Maximum value in dB that can be measured with the current ADC election x value DAC values 1 Pa 3945e006 DAC 0 000e 000 For SYMPHONIE this value is equal to 2 Full scale levels 93 98 dB 20 log 32768xCNA Po in dB with the reference pressure Pp 20 uPa Transducer Unknown Gain 0 00 dB Type of transducer used to acquire the signal Gain on the input signal Annuler PAGE 25 DBFA SUITE USER MANUAL gb_dBFA NUT 043 A 3 3 Plot data items graphics Use the command Pu Datafile

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