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LxT User Manual.book - Pegasus Consultores SAC

1. 5 sections 13 sections sections as 3 sections required Live Average BroadBand History 1 1 OBA Overall SLM 1 1 Oct History 1 3 OBA 1 1 OBA 1 3 Oct History Triggering 1 3 OBA Status Dosimeter 1 Dosimeter 2 Sound Exposure SEA Ln Percentiles Use gt and CI Keys for Scrolling Between Evens Sections Overloads Status Equivalent i Levels Optional Feature FIGURE 3 6 Data Display Screens Changing Data Pages To switch between tab pages use the Left and Right Softkeys Scrolling Between Sections To display different sections Data Views use the LJ and O keys LxT Manual Screens 3 15 Measurement Properties Screen Note that the screen is not wide enough to show the tabs for all thirteen setup pages at the same time Use the Right and Left Softkeys to scroll the view to the right or left respectively For a more detailed description of the Measurement Properties Screen and its associated pages see Chapter 4 Basic Measurement Setup on page 4 1 There are ten Measurement Property Pages in the Measurement Properties Screen identified by their titles on the tabs at the top of the page as follows e General used to create a file name and a measurement description SLM used to setup the parameters for the measurement of sound levels e Dosimeter 1 used to setup the parameters for the measurement of sound exposure and noise dose e Dosimeter 2 used to setup the para
2. Table A 7 Memory Retention Physical Characteristics Length with microphone and 11 35 inches 29 cm preamplifier Length instrument body only 8 80 inches 22 4 inches Width 2 80 inches 7 10 cm Depth 1 60 inches 4 10 cm Weight with batteries no 1 0 lb 471 g preamplifer or microphone Weight with batteries preamplifer 1 1 1b 513 g and microphone Table A 8 Physical Characteristics Technical Specifications LxT Manual Resolution Levels 0 1dB Dose 0 01 Elapsed time 0 1 second Real time clock 1 second Calendar 01 Jan 2005 31 Dec 2038 Table A 9 Resolution Specifications Frequency Weightings Nominal Exact Z Weight A Weight C Weight Electrical Microphone Microphone Frequency Frequency Ideal Ideal Ideal Limits Limits Limits Class 1 or 2 Class 1 Class 2 10 10 00 0 0 70 4 14 3 1 4 0 7 1 5 3 3 0 12 5 12 59 0 0 63 4 11 2 0 5 0 6 1 3 3 3 00 16 15 85 0 0 56 7 8 5 0 4 0 5 1 0 3 3 00 20 19 95 0 0 50 5 6 2 0 3 0 4 0 5 2 0 25 25 12 0 0 44 7 4 4 0 2 0 5 2 0 31 5 31 62 0 0 39 4 3 0 0 2 0 5 2 0 40 39 81 0 0 34 6 2 0 0 2 0 5 1 3 50 50 12 0 0 30 2 1 3 0 5 0 5 1 3 63 63 10 0 0 26 2 0 8 0 5 0 5 1 3 80 79 43 0 0 22 5 0 5 0 5 0 5 1 3 100 100 00 0 0 19 1 0 3 0 5 0 5 1 0 125 125
3. Exchange Rate Q Exchange Rate Exposure Factor k Factor q 3 01 10 1 4 13 333 D s 5 16 667 60 6 02 20 50 There are two types of far fields the acoustic far field and the geometric far field Glossary LxT Manual Free Field Frequency Hz rad sec Frequency Band Pass Filter LxT Manual Acoustic Far Field The distance from a source of sound is greater than an acoustic wavelength In the far field the effect of the type of sound source is negligible Since the wavelength varies with frequency See the definition of Wavelength the distance will vary with frequency To be in the far field for all frequencies measured the lowest frequency should be chosen for determining the distance For example if the lowest frequency is 20 Hz the wavelength at normal temperatures is near 56 ft 17 m at 1000 Hz the wavelength is near 1 1 ft 1 3 m See the definition of Acoustic Near Field for the advantages of in the acoustic far field Geometric Far Field The distance from a source of sound is greater than the largest dimension of the sound source In the far field the effect of source geometry is negligible Sound sources often have a variety of specific sources within them such as exhaust and intake noise When in the far field the sources have all merged into one so that measurements made even further away will be no different See the definition of Geometric Near Field for the advantages of being in th
4. FIGURE 14 1 Control Panel Press the key to open the About Pages There are three About Pages that may be selected using the Right and Left Softkeys All About Pages have one section There is no user input required on these pages LxT Manual About 14 1 About This page gives you important information such as Serial Number and Firmware Revision See FIGURE 14 2 About Page Lo 0 00 02 6 i About About ejecta bigs ENNER Larson Davis Inc LxT1 SoundTrack Precision Integrating Sound Level Meter Corresponds to Instrument Body at Time of Manufacture Instrument Information Serial Number 0000100 Firmware Rev DSP Rev 0 2 Manufactured 2006 Feb 06 Preamp PRMLXxT1L 2006 Jun 44 17 07 25 fos gt Corresponds to Preamplifier Presently Connected FIGURE 14 2 About Page 14 2 About LxT Manual Standards The Standards Page lists the standards that the LxT meets See FIGURE 14 3 Standards Page This instrument conforms to the Following standards Standards ANSI 51 4 1983 Type 1 ANSI 51 43 1997 Type 1 ANSI 51 25 1991 Type 1 IEC 60651 2001 Type 1 IEC 60804 2000 Type 1 IEC 61672 2002 Class 0 IEC 61252 2002 Type 1 IEC 61260 2001 Class 0 ANSI 51 11 2004 Class 1 FIGURE 14 3 Standards Page LxT Manual Standards 14 3 Options Options may be added at any time In the Field Just call one of the telephone numbers listed on the inside front cover or contact your local representa
5. Table A 17 Noise LxT2 PRMLxT2 with 7052 A 30 Technical Specifications LxT Manual LxT2 PRMLxT2L with 7052 LxT2 amp PRMLxT2L 7052S LxT2 PRMLxT2L and 70525 Frequency Noise Noise Noise Hz dB SPL dB SPL dB SPL 6 3 13 9 17 2 13 9 7 9 11 9 16 2 11 9 10 0 10 8 15 2 10 8 12 6 10 7 14 2 10 7 15 8 10 5 13 2 10 5 20 0 9 7 12 2 9 7 25 1 8 9 11 2 8 9 31 6 7 9 10 2 8 0 39 8 A 9 2 7 4 50 1 6 0 8 2 6 2 63 1 5 6 7 2 d 5 8 79 4 4 2 6 2 4 6 100 0 3 6 5 2 4 1 125 9 2 8 4 2 3 6 158 5 18 3 2 3 0 199 5 1 2 2 2 2 8 251 2 0 7 1 2 2 8 316 2 0 3 0 2 3 1 398 1 0 1 0 8 3 4 501 2 0 1 1 8 3 9 631 0 0 4 2 8 4 5 794 3 0 1 3 8 5 3 1000 0 0 1 4 8 6 1 1258 9 0 6 5 5 6 7 1584 9 1 0 6 4 75 1995 3 1 6 7 0 8 1 2511 9 2 1 7 5 8 6 3162 3 2 7 8 0 9 1 3981 1 3 4 8 4 9 6 5011 9 4 0 8 8 10 0 6309 6 4 7 9 2 10 5 7943 3 5 4 9 5 10 9 10000 0 6 2 9 6 11 2 12589 3 7 1 9 4 11 4 15848 9 7 8 8 8 11 3 19952 6 8 7 8 5 11 6 Awt 14 9 20 8 Cwt 17 5 22 8 Zwt 23 4 28 1 Table A 18 Noise LxT2 PRMLxT2L with 7052 LxT Manual Technical Specifications A 31 Microphone Preamplifier Specifications The general specifications for the LxT microphone preamplifiers are shown in Table A 19 LxT Preamplifiers a Nominal Nominal Nominal sensitivity Nominal Microphone Preamplifier y EE Sensitivity Limits Se at LxT Sensitivity Sensitivity Attenuation Input Preamplifier a Model mV Pa dB mV P
6. Electrostatic Discharges The LxT is not affected by electrostatic discharges Table A 3 General Specifications Technical Specifications LxT Manual AC DC Output AC output voltage range 1 00 Volts peak 70 dB dynamic range DC output voltage range 0 to 3 Volts 0 to 300 dB VO SPL 100 SPL 100 x VO or Sensitivity 0 01 V dB with resolution of 0 001 V AC output Low impedance speaker driver impedance instrument readings are not affected by AC or DC output loading DC output 3650 Q impedance AC DC output 2 5 mm stereo jack connector Tip DC out Ring AC out Sleeve Ground When using the CBL139 cable the DC signal is on the White connector and the AC signal is on the Red connector Table A 4 AC DC Output Specifications Power Supply Batteries 4 AA LR6 Alkaline or NiMH cells External power Powered through USB interface from computer or AC DC converter PSA029 5 volt 5 required Table A 5 Power Supply Specifications Technical Specifications A 6 Operating Life Battery Hours 4 AA LR6 Alkaline cells 16 Table A 6 Internal Battery Operating Lifetime Memory Retention without Batteries or External Power Data memory Permanently stored in non volatile flash memory every one minute If power failure maximum data loss will be less then one minute Real time Clock gt 10 minutes
7. Hex Driver and 4 replacement screws used to secure the battery door to prevent battery exchange in explosive atmospheres User Manual I770 01 Record Serial Numbers of LxT and Components 2 2 If you have not already done so please record the purchase date the model and serial numbers for your instrument preamplifier and microphone in the spaces provided on the copyright page LxT Model LxT1 LxT2 Serial Number on page i iii You will find the instrument s Model and Serial numbers printed on the label on the instrument s back panel The microphone s model and serial numbers are engraved on the outside of the microphone as shown in FIGURE 2 1 Microphone The preamplifier s model and serial numbers are engraved on the outside surface of the preamplifier You may be asked to provide this information during any future communications with Larson Davis Inc FIGURE 2 1 Microphone Unpacking and Inspection LxT Manual Connecting the Microphone and Preamplifier The bottom end of the microphone attaches to the top end of the preamplifier The top end of the preamplifier has a single gold pin and threads on the preamplifier body The model and serial number of the microphone are engraved on the side FIGURE 2 2 Microphone Preamplifier Carefully place the bottom end of the microphone over the top end of the preamplifier and gently screw the assembly together The microphone body will seat smoothly against the pre
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9. LCD Display Connectors FIGURE 1 3 The LxT The SoundTrack LxT is a convenient hand held sound level meter real time analyzer with a simple user interface The standard LxT shown in FIGURE 1 3 includes the following 1 2 in diameter condenser microphone e Backlit graphic 160 x 240 pixel LCD display e 13 key soft rubber backlit keypad e AC DC output control USB and external power connectors shown in FIGURE 1 4 e True hand held instrument with sure grip pads LxT Manual Features 1 13 Hardware Power Switch Ue Cnteriace AC DC Output and Headset Sa ees ee cc a KH AUX Connector FIGURE 1 4 LxT Bottom View 1 14 Features LxT Manual First Use This chapter outlines the steps to unpack the LxT and prepare it for first use The following topics are covered e Unpacking and Inspection e Connecting the microphone and preamplifier e Installing 4 AA batteries Using USB power You will then be ready to use the LxT for actual measurements Unpacking and Inspection Your LxT has been shipped in protective packaging Please verify that the package contains the items listed below Retain the packaging for safe shipment for calibration service Report any damage or shortage immediately to Larson Davis Inc at 888 258 3222 U S toll free or 716 926 8243 s LxT PRMLxT Microphone Preamplifier e Microphone e Lanyard 4 AA Alkaline Batteries LxT Manual First Use 2 1
10. SEL Calculations SEL is available for the overall measurement and is calculated using this formula mn Lg SEL Leat ke log 10 10g 32 s 1 All of the SEL energy values in the analyzer utilize the Threshold and Exchange Rate settings Care should be taken when modifying these settings since some standards or governments require SEL to be taken without a Threshold set it to zero and with an Exchange Rate of 3dB Integrated Level Calculations Model 831 Manual LD 0 08 03 9 831_Data dl Overall ESSAU EA Sound Exposure Level Sound Exposure Level gt Sound Exposure in hours __ gt Sound Exposure in seconds p Sound Exposure EAS 5 767m Pa2h EAS8 343 2m Pa2h EAS40 1 7162 Pa2h EAS 20 762 Pa s EAS8 1235 6 Pa2s EAS40 6178 2 Pa s Run Time 0 08 03 9 FIGURE C 2 Sound Exposure Level and Sound Exposure Dose and Projected Dose Calculations See FIGURE C 3 DOSE and Pro jected DOSE Dose is a measure of Sound Exposure and is defined in ANSI 51 25 Section 4 7 as T t D Q Ga fio 9 dt 0 where D Q is the percentage criterion exposure for exchange rate Te is the criterion sound duration 8 hours T is the measurement duration in hours t is the time in hours Model 831 Manual Integrated Level Calculations C 5 L is the SLOW or FAST A weighted sound level a function of time when the sound level is greater than or equal to L or equals x when the A wei
11. The Reset Button is used to reset a measurement The Tools Button is used to set a number of parameters not associated with a specific measurement such as setting date and time managing power options and setting personal preferences i e language decimal and date formats etc Table 3 1 Keypad Hardkeys Components LxT Manual Connectors and Interfaces Hardware Power Switch USB Interface AC DC Output and Headset A lo AUX Connector FIGURE 16 3 LxT Bottom Panel DO NOT use the hardware power switch to turn the LxT ON or OFF This will cause data to be lost See Hardware Power Switch on page 2 7 for additional information on the use of the hardware power switch LxT Manual AUX Connector reserved for future developments Hardware Power Switch when set to O completely powers down the LxT with the exception of permitting the real time clock to continue Set to for instrument operation USB Interface used for communication with a PC utilization of USB memory devices control of the LxT from the PC and downloading of data from the LxT to the PC The PSA029 external power supply may be connected here AC DC Output and Headset Jack used to output analog AC and DC signals or to connect to a headset for the recording and playback of voice records See Jack Function on page 11 12 Components 16 5 Batteries See Chapter 3 Page on page 3 7 16 6 Power Control
12. all SLA While the overload is present the icon will flash on and off When the overload is removed the icon will be removed from the display If a measurement is running and an overload occurs the icon will flash during the overload When the overload has been removed the icon will still be present not flashing to indicate that an overload has occurred during the measurement A reset will clear the icon from the display At any time the measurement of overall data can be temporarily suspended by pressing the 2 RUN PAUSE key Note that the run clock will also pause However instantaneous data will continue to be displayed in the Live View Pressing Cay RUN PAUSE key one more time will cause the measurement to begin again and overall data will continue to be accumulated The run clock will also begin again from the time indicated when the pause had occurred The overall data will not be affected by any acoustic events occurring during the time period that the LxT was paused Performing the Measurement 7 11 Resetting the Measurement A measurement is most often reset To reset a measurement in progress press the D RESET when a noise event which is not key This will erase all data previously measured and reset typical of the measurement desired the run time clock to zero A reset will not reset stored data takes place For example an aircraft files passing overhead when attempting to measure the background noise in
13. Energy Equivalent Sound Level Sound Level Energy Average and Time Weighted Average Glossary D 11 Level dB Measurement Duration T Microphone Guidelines D 12 A descriptor of a measured physical quantity typically used in sound and vibration measurements It is attached to the name of the physical quantity to denote that it is a logarithmic measure of the quantity and not the quantity itself The word decibel is often added after the number to express the same thing When frequency weighting is used the annotation is often expressed as dB A or dB C The time period of measurement It applies to hearing damage risk and is generally expressed in hours Standard ANSI S12 19 Microphone Types A device for detecting the presence of sound Most often it converts the changing pressure associated with sound into an electrical voltage that duplicates the changes It can be composed of one of the following types Capacitor Condenser A microphone that uses the motion of a thin diaphragm caused by the sound to change the capacitance of an electrical circuit and thereby to create a signal For high sensitivity this device has a voltage applied across the diaphragm from an internal source Electret A microphone that uses the motion of a thin diaphragm caused by the sound to change the capacitance of an electrical circuit and thereby to create a signal The voltage across the diaphragm is caused by the char
14. Note that using the backlight on bright setting will significantly increase power consumption and decrease battery life Display Contrast Note that the Display Contrast can also be set from the display by pressing the key as described in the section ON OFF Key on page 3 6 This is the preferred method of adjusting contrast because the changes are made immediately With the method described here the change is not applied until the System Properties display is closed LxT Manual This sets the duration of time the backlight remains on after the last key press Available choices are 5 sec e 10 sec e 30 sec e 60 sec e Always On The default is 10 sec This field sets the intensity of the backlight Options for backlight mode are Off Dim and Bright The default is Off The Backlight mode can also be set by pressing the key as described in the section ON OFF Key on page 3 6 This parameter is used to adjust the contrast of the display to accommodate varying viewing angles temperature and lighting condition Adjustment ranges from 9 to 9 The default is 0 Power 11 7 Battery Type To avoid damage to batteries always Select the type of battery installed in the LxT This set the correct battery type information is used for the calculation of battery life Available battery types are Alkaline and NiMH The default is Alkaline Preferences The Preferences Page is
15. Section 9 displays the Ln statistics for the measurement based on the run time Also shown are the maximum and minimum sound levels measured An Ln is the level that was exceeded n percent of the time LxT Manual Overall Page 5 17 Events 0 0 00 00 0 0 0 00 00 0 0 0 00 00 0 LZpeak gt 135 0 dB 0 0 00 00 0 Run Time 0 00 54 6 FIGURE 5 15 Overall Page Section 10 Section 10 shows the number of exceedances that have occurred during the measurement and the total duration of exceedances Exceedances are shown for two threshold levels of the RMS detector and three for the peak detector Overall Page LxT Manual Overloads EY 0 00 54 6 LxT_Data Dverloads Run Time 0 00 54 6 FIGURE 5 16 Overall Page Section 11 Section 11 shows the overloads which have occurred during the measurement LxT Manual Overall Page 5 19 Number of Measurements EY 0 00 10 4 Z LxT_Data 2006 Jun 08 13 31 15 n a n a 103340kB of 111050kB 9 Data Files Started 2006 Jun 08 13 50 48 FIGURE 5 17 Overall Page Number of Measurements by Type Section 12 Section 12 presents the quantity of each type of measurement which has been made and also the memory status 5 20 Overall Page LxT Manual Equivalent Levels The parameter LAFTMS will only appear when Takt Maximal Data has been selected on the Preferences Page as shown in Takt Maximal Data on page 11 13 LxT Manual aq 0 00
16. To activate the System Property Pages press the A TOOLS key Use the C O O or O keys to highlight the System Properties icon as shown in FIGURE 11 1 Control Panel Data Calibrate Explorer System Properties FIGURE 11 1 Control Panel Press the key to open the System Property Pages There are four System Property Pages that may be selected using the Right and Left Softkeys All System Property Pages have one section System Properties 11 1 Device It is easier to enter the text information for these three fields using the Blaze software or the SLM Utility G3 software 11 2 The Device Page has three fields in which the user may enter information about the instrument This can identify the owners company name and address Information may be easily placed in these fields using Blaze software lt gt 0 00 00 0 Su ystem Properties Device OTTEN Instrument Identification Cl A od FIGURE 11 2 Device Page Using the 7 and_ keys select one of the three fields to edit Press the key to highlight the lst character position in the field The 7 CA and keys are used to scroll through a list of characters and change character positions in the field When the information is complete press the key to accept the information and move the highlight out of the field At this point another field could be selected and the above process repeated Device LxT Manual Time Setting Day and Year Selectin
17. key to highlight the name portion of the highlighted box Then press the Gast key Use the O o CI and E keys to enter the desired characters Press the key to complete your entry Dosimeter 1 and 2 Pages LxT Manual Parameter Fields Exchange Rate Threshold and Criterion Note that when setting the Threshold value the Enabled check box must be checked before data can be entered into the numeric field Use the Left Softkey to highlight the box and press the amet key Auto Calculate LxT Manual The titles of the second field Exchange Rate and the two sections at the lower portion of the display Threshold and Criterion correspond to the three parameters we wish to set Within each is a numeric field into which the user can enter the value desired Use the LC and keys to highlight the desired section and proceed as described below To set the exchange rate highlight the data field and press the key to open a drop down list of values as shown in FIGURE 4 8 Exchange Rate List Exchange Rate Threshold EEnabled FIGURE 4 8 Exchange Rate List Use the 7 and keys to highlight the desired value and press the key to make the selection To set these parameters after highlighting the appropriate section press the Ger key use the 2 C3 and gt keys to enter the numeric value desired then press the key As described above the Criterion Level and Time are set independently However in the standa
18. 00 016 0 10 0 10 12 0 02 016 0 08 0 12 6309 60 00 016 0 10 0 10 62 0 02 016 0 08 0 12 7943 30 00 016 0 10 0 10 81 0 02 016 0 08 0 12 10000 00 00 016 0 10 0 10 12 0 01 016 0 09 0 11 12589 00 01 016 0 10 0 10 10 0 01 016 0 09 0 11 15849 00 01 016 0 10 0 10 43 0 01 016 0 09 0 11 19953 00 01 016 0 10 0 10 00 0 01 016 0 09 0 11 25250 00 01 022 0 10 0 10 89 0 01 016 0 09 0 11 31500 00 02 022 0 10 0 10 49 0 01 016 0 09 0 11 39750 00 02 022 0 10 0 10 ER 0 01 016 0 09 0 10 50000 00 03 022 0 12 0 12 DE 0 01 016 0 10 0 10 63000 00 04 047 0 14 0 14 ER 0 00 016 0 10 0 10 79500 00 06 047 0 16 0 16 TL 0 00 016 0 10 0 10 100000 00 07 047 0 18 0 18 19 0 00 016 0 10 0 10 126000 00 09 063 0 20 0 20 Noise floor data 1kHz 1 3 Octave 0 37 uV 8 6 dBuV uncertainty 0 47 dB Flat 20Hz 20kHz 3 7 uV 11 3 dBuV uncertainty 0 47 dB Awt 2 3 uV 7 4 dBuV uncertainty 0 46 dB Uncertainties are given as expanded uncertainty at 95 confidence level k 2 Technician Jason Grace Test Date O9MAR2005 FIGURE A 20 Certificate of Conformance PRMLxT2L A 50 Technical Specifications LxT Manual APPENDIX Testing to IEC61672 1 This appendix presents information for measuring the sound level meter functionality of the LxT according to IEC61672 1 Sections 5 6 7 and 9 except 9 3 The fol
19. 00 00 00 00 00 00 Liz Close FIGURE 6 11 Daily Timer Mode The run mode is indicated at the top as Daily Timer Mode This mode is used when measurements are to be made daily over the same non overlapping time intervals up to three can be programmed As seen in Figure 6 11 the Start and End dates and the Start and End times for the first interval are set in the same manner as used for the Single Block Timer Mode as described in Single Block Timer Mode on page 6 7 Placing check marks in the check boxes 2 and 3 will open Run Modes 6 9 data fields to define the Start and End times for the 2nd and 3rd time intervals as shown in Figure 6 12 x 2 x3 00 00 00 d Close FIGURE 6 12 Daily Timer Three Timed Stop Mode 6 10 Run Modes LxT Manual Making a Measurement In this chapter we describe how to make and store an accurate sound level measurement Before doing this make sure that the LxT has been setup to meet the requirements for the measurement as described in Chapter 4 Basic Measurement Setup on page 4 1 Configuration of the System The use of the microphone extension cable EXCXXX where XXX is the length in feet XXX 010 020 025 035 050 060 100 and 200 available will not affect the ability of the LxT to comply with standards referenced in this manual LxT Manual The System LxT should be configured as shown in Figure 1 3 on page 13 with the preamplifier connected t
20. 4189 Serial Number 2440346 Tested 11 23 05 08 44 02 FIGURE A 3 LxT with 377B02 Microphone 0 60 120 and 180 degree A 16 Technical Specifications LxT Manual LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 Tested 11 23 05 12 25 57 by Alex T Note PRMLxT1 0155 and 377B02 100650 Reference Mic B amp K Model 4189 Serial Number 2440346 Tested 11 23 05 08 44 02 6 0 dB 2 0 dB 2 0 dB 6 0 dB 10 dB 14 dB 18 dB Mic 135 FIGURE A 4 LxT with 377B02 Microphone 15 75 and 135 degrees LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 Tested 11 23 05 12 25 57 by Alex T Note PRMLxT1 0155 and 377B02 100650 Reference Mic B amp K Model 4189 Serial Number 2440346 Tested 11 23 05 08 44 02 6 0 FIGURE A 5 LxT with 377B02 Microphone 30 90 and 150 degrees LxT Manual Technical Specifications A 17 A 18 LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 Tested 11 23 05 12 25 57 by Alex T Note PRMLxT1 0155 and 377B02 100650 Reference Mic B amp K Model 4189 Serial Number 2440346 Tested 11 23 05 0
21. 95 confidence level k 2 Technician Ron Harris Test Date 20JAN2006 FIGURE A 19 Certificate of Conformance PRMLxT2 LxT Manual Technical Specifications A 45 Model PRMLxT2L The Larson Davis PRMLxT2L is an electret microphone preamplifier It requires very little supply current and will drive 100 feet of cable The preamplifier operates over wide temperature and humidity ranges It is for use with 20 mV Pa sensitivity microphones up to 126 dBSPL Specifications Frequency response with respect to the response at 1 kHz with 1 1 Volts rms input and 18 pF equivalent microphone 4 Hz to 10 Hz 0 1 0 5 dB 10 Hz to 20 kHz 0 1 0 18 dB Lower 3 dB limit lt 1 5 Hz Attenuation 1 2 dB typical Input Impedance 10 G Ohm 3 pF Output Impedance 50 Ohm Maximum Output With LxT SLM 2 Vpp 126 dB peak for microphones with 20 mV Pa sensitivity Maximum Output Current 10 mA peak A 46 Technical Specifications LxT Manual Distortion Harmonics lt 62 dBc with 1 1 Volts rms input at 1 kHz Output Slew Rate 2 V uS typical Electronic Noise with 18pF equivalent microphone 1 8 pV typical A weighted 2 5 uV max 3 2 uV typical Flat 20 Hz to 20 kHz 5 uV max Power Supply Voltage 6 to 15 Volts DC Output Level 1 2 power supply voltage Power Supply Current 1 3 mA typical Temperature Sensitivity lt 0 05 dB from 10 to 50 C 14 to 122 F operating range to 60 C 140 F Humidity Sensitivit
22. 97 63 10 42 00 inf 0 01 10 30 0 60 A 96 71 10 61 00 inf 0 00 10 30 0 40 97 53 10 70 00 inf 0 00 10 30 0 30 Table A 14 Filter Skirts of 1kHz 1 3 Octave Filter LxT Manual Technical Specifications A 13 Position of Instrument and Operator When making a measurement it is recommended that the observer be positioned as far behind and to the right of the instrument as possible to minimize interference of the sound field at the microphone resulting from body reflections When using the LxT the meter is held in one hand with the arm extended away from the body Better results can be obtained by using a tripod Effect of Windscreen The Corrections which should be subtracted from the measured data when using the Larson Davis Model WS001 3 inch diameter windscreen with a Y2 inch Larson Davis microphone are as indicated in the following graphs Windscreen Response with Respect to No Windscreen 0 Degree Incidence Frequency Hz FIGURE A 1 Effect of Wind Screen 0 Incidence A 14 Technical Specifications LxT Manual 90 Degree Incidence Frequency Hz FIGURE A 2 Effect of Wind Screen 90 Incidence LxT Manual Technical Specifications A 15 Frequency Response LxT With 377B02 Free Field Microphone and PRMLxT1 Preamplifier LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 Tested 11 23 05 12 25 57 by Alex T Note PRMLxT1 0155 and 377B02 100650 Reference Mic B amp K Model
23. B Weighting A filter that adjusts the levels of a frequency spectrum in the same way the human ear does when exposed to higher levels of sound This weighting is seldom used See table below C Weighting A filter that adjusts the levels of a frequency Glossary LxT Manual LxT Manual spectrum in the same way the human ear does when exposed to high levels of sound This weighting is most often used for evaluation of equipment sounds See table below Flat Weighting A filter that does not adjust the levels of a frequency spectrum It is usually an alternative selection for the frequency weighting selection Center Frequencies Hz Weighting Network Frequency Response 1 3 Octave 1 Octave A B C 20 50 4 24 2 6 2 25 44 7 20 4 4 4 31 5 31 5 39 4 17 1 3 0 40 34 6 14 2 2 0 50 30 2 11 6 1 3 63 63 26 2 9 3 0 8 80 22 5 7 4 0 5 100 19 1 5 6 0 3 125 125 16 1 4 2 0 2 160 13 4 3 0 0 1 200 10 9 2 0 0 250 250 8 6 1 3 0 315 6 6 0 8 0 400 4 8 0 5 0 500 500 3 2 0 3 0 630 1 9 0 1 0 800 0 8 0 0 1000 1000 0 0 0 1250 0 6 0 0 1600 1 0 0 0 1 2000 2000 1 2 0 1 0 2 2500 1 3 0 2 0 3 3150 1 2 0 4 0 5 4000 4000 1 0 0 7 0 8 5000 0 5 1 2 1 3 6300 0 1 1 9 2 0 8000 8000 1 1 2 9 3 0 10000 2 5 4 3 4 4 12500 4 3 6 1 6 2 16000 16000 6 6 8 4 8 5 20000 9 3 11 1 11 2 See
24. SOftke ys vel Al o es an dea ao Ds dl le dd 16 3 PZ DOAK ia dass 5 3 5 9 EZ peak Max EE 5 9 5 10 M Making a Measurement ooonooccccococcoococcoccononoconononooncoo ronca non nono ro non non ron rna non ron ronna nano 7 1 Calibrating e 7 5 Low Level Sound Fields ica 7 16 EXT SOU NEE 7 5 Measurement Display DAS cd dE Hostess 7 8 Measureinent Ram 86 ici EENEG 7 11 Microphone Extension Cable cccecccsccescesseescesecesceseececeseeanecseeeaecsaecaecaeenseensenseeereaes 7 6 Observer Position Seeerei io 7 5 Overload Indica tati tii die 7 11 Pauisinig the Measures de dias 7 11 Performing the Measurement ssssesesseeeeseeeeeessteessesesesresessestesteresreseseeseeresrenessesesses 7 8 Ne Ee 7 5 Resetting the Measurement nono nonronnnnn ron rrnn rro ron ran ron nrannnnnns 7 12 UM o e 7 4 Start up Te 7 2 Stopping the Measurement cias 7 13 Storing the Measurement ocooocoonoonoonnonnnononnconnonnnon non nnonnonnronnnn nn nr cnn rnn rn n ron rrnnr an ronnran naar 7 14 EE 7 2 Us of Windscreens sox vaste isi ot ceeds acta Ee ia 7 6 er 7 4 Measurement Name 3 3 Measurement Properties Screen oonoconococccccccccconcconcnnnonnconnconocnncnonanonnonanonannnos 3 13 3 16 4 2 A e AT 4 2 Controls is a ds 3 16 A A A devas 3 16 E O E 3 16 EE E 3 16 Disha ees Alen henna he ewan We Bia Alen ean 3 16 an Eeer 4 12 Mia eege 3 16 OBA orig ee etc 3 16 Octave Band Analyzer Hagen ites ek hia bea See 4 13 ETH SCC eshte eerste ed 4 2
25. Selecting Displays to Appear Tab Page Selection 11 14 When there are measurement functions not being used or data displays which are not of interest for a measurement the instrument operation can be streamlined by hiding selected displays As a default all available displays are set to appear Use the key to highlight the Tabs field to to list the tab pages for which displays can be set to appear or be hidden as shown in FIGURE 11 14 Displays LxT Manual Session Log 1 1 Time History LO FIGURE 11 14 Display Tab Page Options Use the 7 and E keys to highlight the desired Tab Page and press the key to make the selection Display Selection The displays which can be set to appear or be hidden are shown below for each of the possible Tab Page selections Live Page Displays 5 Live Profile 1 1 Octave 1 3 Octave Trigger Power FIGURE 11 15 Live Page Displays LxT Manual Displays 11 15 Overall Page Displays 13 Overall v 1 1 Octave 1 3 Octave Dose 1 Dose 2 SEL FIGURE 11 16 Overall Page Displays Session Log Display abs Session Log FIGURE 11 17 Session Log Displays Time History Displays 3 Time History 1 1 Octave 1 3 Octave FIGURE 11 18 Time History Displays All displays which have a check in their check box will appear on the LxT To modify any of the displays associated with one of the Tab Pages use the or C keys to highlight the field listing 11 16
26. Set p PAGES ss aise A a dass 4 3 LxT Manual a 7 Time HIStory rra 3 16 A AN 3 16 Triggers EE 4 20 Measurement Status oo cece ccccsecseeecseseceeseceeneeeceececeececeececneecneescneeecnessenesseeeeaees 3 4 PAUSE ICONS see ti EE 3 4 Reset Teon zo eg reene Diego ege ee E deer EA 3 4 Rum 1 COD tl E ANN 3 4 e 3 4 LOTS O RN 3 5 Nemme Genesis A oc pe ee es 5 7 Memory Status ic ii thick nei it en ea iene a 5 7 Memory Utilization seed A RE 18 1 Microphone Guidelines sc 22 ceciet econ ced eee gh i n D 12 What 1teasures xcs ces Meet DEE ee Rea D 13 Microphone Extension Cable o ooocoocionocccicocononcnonncononnonaconacnornnconocinonnornnonos 7 6 Microphone Preamplifier Specifications 0 00 snesosessosessosossesesesrssresssissesesse A 32 PRM E KE A 37 PRINT et Ee Eeer A 32 PRM een erties teal A AA ase hee A 41 LS E EE EE A 46 Microphone Preamplifier CR A a a a a a a a T 2 4 Connecting Together eer e rio E ia 2 3 Dorain nTa EES S AN EET E E EEE 2 5 Microphones A E E E A ATE D 12 Electret cranieni A RE E ER D 12 BCEE E D 12 Move Horizontally lt ooo io aes eden EEN 3 11 Move Vertically e cocino tattoo iva 3 11 N Near Field O EEN D 14 EE eet seed E E ees D 14 o D 14 Noise o NN D 15 Bar A o ee e E D 15 Daily EE EE D 3 RN RE D 15 EXPO SERA EES D 16 a 8 LxT Manual EE D 2 D 15 Pl eege Aere cian D 15 Projected As di aia D 16 Single event exposure dere lui tb ated D 16 WI
27. The installation of batteries into the LxT is discussed in Chapter 2 Inserting Alkaline Batteries on page 2 6 The LxT is compatible with AA alkaline and nickel metal hydride batteries Energizer Duracell and other nationally recognized brands are the preferred suppliers of alkaline batteries These will provide the user with the best battery life estimation Energizer and Ray O Vac 2500 mAH AA NiMH batteries and their respective fast chargers are also recommended CAUTION e NiMH batteries cannot be charged in the LxT Do not mix alkaline and NiMH batteries in the LxT Do not mix batteries from different manufacturers e Replace all four batteries when installing fresh cells e NiMH batteries may not be used in areas requiring Intrinsic Safety Approval Battery Voltage and Estimated Run Time are displayed on the Power Control screen and the last section of the Live Pages FIGURE 16 4 Battery Status Icons A battery icon is always available in the status bar at the top of the screen The icon shows the state of the battery charge as a full icon with fresh batteries decaying to an empty battery near the end of the battery life The battery voltage and the state of the battery icon directly reflect the remaining Estimated Run Time as displayed by the instrument Batteries LxT Manual As the battery nears end of life the empty battery symbol will begin to flash The unit will shut down in a short time because the battery v
28. on page 11 12 9 2 6 Accessories a Effect of Windscreen on page A 14 b Microphone Extension Cable on page 7 6 c Octave Band Analyzer Page Optional on page 4 13 d No manufacturer provided auxiliary devices are provided 9 2 7 Influence of variations in environmental conditions a No components of the LxT are intended to be operated only in an environmentally controlled enclosure b Declaration of Conformity on page A 2 c Microphone Reference Point on page B 10 The following two sections are related to the LxT1 and the LxT2 configurations respectively In each information is provided which corresponds to the specific item number in this standard LxT Manual Sections 5 6 7 and 9 except 9 3 LxT1 Section 9 2 4 a Calibrator The calibrator to be used with the LxT1 is the Larson Davis Model CAL200 b Calibration Frequency The calibration check frequency is 1000 Hz c Calibration Procedure For calibration refer to the chapter Calibration on page 10 1 B 8 LxT1 LxT Manual d Frequency Response and Corrections Table 1 Larson Davis LxT1 with PRMLxT1 and typical 377B02 Microphone average frequency responses and corrections Required by IEC 61672 1 Sections 5 2 4 5 2 5 5 2 6 and 9 2 4 d 0 Free Field Corrections with Wind Screen on LxT1 Wind Screen on LxT1 0 Free Field 0 Free Field Response 0 Free
29. up menus Throughout this manual there are cross reference links to other chapters and figures The cross reference may appear similar to FIGURE 3 5 Measurement Properties Screen page 3 3 Left click on these text areas to display the page associated with that cross reference To return to the previously displayed page click the View Menu in the menu bar Click Goto and then Previous View on the pop up menus Special Features of the Electronic Version LxT Manual Features Hardware Features LxT Manual The Larson Davis SoundTrack LxT has the following features Precision integrating sound level meter 64 MB unformatted standard data memory 120 MB optional 160 X 240 graphic LCD display with backlight and icon driven user interface Silent Touch elastomeric keypad Large dynamic range providing single SLM display page RMS Detectors Slow Fast amp Impulse RMS Frequency Weighting A C amp Z Peak Frequency Weighting A C amp Z Ly Statistics 6 user selected values over the range Lo o1 through Log 99 and Histogram tables Jack for AC DC output or headset microphone and speaker Compatible with 61 m 200 ft microphone extension cable full scale to 20 kHz 4 AA batteries provide 16 hour operating time USB 2 0 full speed peripheral connector and AC DC output Field upgradeable firmware WS001 windscreen Features 1 7 Basic Measurements Basic Operation 1 8 SPL Le
30. 1 1 or 1 3 octave real time frequency spectra measurements or they can both be measured simultaneously These spectra will be made using a user selected frequency weighting A C or Z The averaging time is the same as that selected for the sound level measurements Fast Slow or Impulse Spectral data is displayed on both the Live and Overall Pages but only the Overall Data can be stored Live Page From the Live Page the graphic shows the instantaneous SPL value for all frequencies and the bar to the far right shows the summation value for the entire frequency band The value corresponding to the cursor position is displayed numerically beneath the graph Basic Sound Level Measurements 17 3 Overall Page From the Overall Page the graphic shows the energy equivalent level calculated over the measurement time period at each frequency band and at the far right for the summation of all frequency bands The values displayed digitally beneath the graph represent the following data for the frequency band at the cursor position e Leq e Lmax e Lmin Sound Exposure Metrics Measured See Chapter 9 Industrial Hygiene on page 9 1 The LxT measures two separate and independent sets of sound exposure metrics The following parameters are user selectable Exchange Rate 3 4 5 or 6 dB e Threshold Enable Yes or No e Threshold Level Numeric entry e Criterion Level and Hours Numeric entries In Table 17 2 Sound Expos
31. 1 8 1 8 0 6 2 4 2 4 0 6 10000 00 1 9 1 9 0 6 2 5 2 5 0 6 10592 54 1 8 1 8 0 4 2 2 2 2 0 7 11220 18 1 2 1 2 0 4 1 6 1 6 0 8 11885 02 1 0 1 0 0 6 1 6 1 6 0 9 12589 25 4 0 1 0 0 4 1 4 1 4 1 0 13335 21 1 0 1 0 0 4 1 4 1 4 1 0 14125 38 1 1 1 1 0 3 1 4 1 4 1 0 14962 36 1 0 1 0 0 2 1 2 1 2 1 0 15848 93 1 0 1 0 0 6 1 6 1 6 1 0 16788 04 1 4 1 4 0 9 2 3 2 3 1 0 17782 79 1 6 1 6 0 5 2 1 2 1 1 0 18836 49 1 9 1 9 0 8 2 7 2 7 1 0 19952 62 2 6 2 6 0 8 3 4 3 4 1 0 add numbers in this column to levels raad on the LxT2 to correct the level at a specific frequency Section 9 3 a Reference Sound Pressure Level The reference sound pressure level is 114 dB re 20 pPa b Reference Level Range The reference level range is normal c Microphone Reference Point The microphone reference point is the center of the diaphragm of the 7052 microphone d Periodic Testing See table 2 for values of Larson Davis LxT2 with PRMLxT2 and 7052 Microphone adjustment data of A weighted levels used for periodic measurements LxT Manual LxT2 B 15 Fre Table 2 Larson Davis LxT2 with PRMLxT2 and 7052S Microphone adjustment data of A weighted levels used for periodic testing quency 0 Free Field Corrections B amp K 4226 Calibrator 0 Free Field from Corrections with WS B amp K 4226 Calibrator from 0 Free Field 0 Free Field Corrections Corrections with WS from from B amp K UA003
32. 107 12 EN 16 18 50000 100000 0 D 0 D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 LxT Manual Model PRMLxT2 The Larson Davis PRMLxT2 is an electret microphone preamplifier for use with Larson Davis LxT Sound Level Meters It requires very little supply current and will drive 200 feet of cable The preamplifier operates over wide temperature and humidity ranges It has a built in attenuation of 15 dB for use with 20 mV Pa sensitivity microphones up to 140 dBSPL Specifications Frequency response with respect to the response at 1 kHz with 5 3 Volts rms input and 18 pF equivalent microphone 2 5 Hz to 10 Hz 0 1 0 25 dB 10 Hz to 40 kHz 0 1 0 1 dB Lower 3 dB limit lt 1 Hz Attenuation 14 6 dB typical Input Impedance 10 G Ohm 40 pF Output Impedance 50 Ohm Maximum Output 2 8 Vpp 143 dB peak for microphones with 20 mV Pa sensitivity Maximum Output Current 10 mA peak LxT Manual Technical Specifications A 41 Distortion Harmonics lt 67 dBc with 0 7 Volt rms output at 1 kHz Output Slew Rate 2 V uS typical Electronic Noise with 18pF equivalent microphone 1 0 uV typical A weighted 1 4 uV max 1 4 uV typical Flat 20 Hz to 20 kHz 2 2 uV max Power Supply Voltage 6 to 15 Volts DC Output Level 1 2 power supply voltage Power Supply Current 1 3 mA typical Temperature Sensitivity lt 0 05 dB from 10 to 50
33. 20 kHz 2 1 uV max Power Supply Voltage 6 to 10 Volts DC Output Level 1 2 power supply voltage LxT Manual Technical Specifications Power Supply Current 1 3 mA typical Temperature Sensitivity lt 0 05 dB from 10 to 50 C 14 to 122 F operating range to 60 C 140 F Humidity Sensitivity lt 0 05 dB from 0 to 90 RH non condensing at 40 C 104 F Dimensions 12 7 mm diameter x 73 mm length 0 50 dia x 2 88 length Microphone Thread 11 7 mm 60 UNS 0 4606 60 UNS Cable Driving Capability LxT SLM 1 V rms output signal To 20 kHz with 200 61 m cable All values are at 23 C 50 RH 7 5 Volt supply 3 m 10 cable and equivalent microphone of 18pF unless otherwise stated Output Connector Switchcraft TASM 5 Pin male Pin Signal 1 Signal Ground 2 Signal Output 3 Power Supply 7 Volts Table A 20 Output Connector A 34 Technical Specifications LxT Manual Pin Signal 4 Preamp sense 5 No Connection Shell Connect to preamp housing Table A 20 Output Connector Compatibility Use with Larson Davis 377B02 or any Y electret microphone having about 50 mV Pa sensitivity and meeting the mechanical requirements of IEC 61094 4 It can be used with either the Larson Davis ADP043 or ADP008 adapters for 1 4 or 1 electret microphones In the interest of constant product improvement specifications are subject to change
34. 6 Allow Cal Check Box Fully Locked gt 0 00 00 0 0 Date 2006 Mar 06 15 27 37 This instrument has been LOCKED Press the Tools key to UNLOCK FIGURE 12 7 Fully Locked 12 6 Fully Locked LxT Manual If you have selected Fully Locked for the Lock Mode upon accepting the changes FIGURE 12 7 Fully Locked represents the view you will have At this point the instrument is not running a measurement It is possible to select the Fully Locked mode while a measurement is in progress Pressing the a RUN PAUSE key will start a measurement by bring up the following message box gt 0 00 00 0 0 Date 2006 Mar 06 15 29 04 This instrument has been Run 4re you sure Ho Press the Tools key to UNLOCK FIGURE 12 8 Are You Sure Use the O O and keys to select the desired response Selecting Yes will begin the measurement A measurement cannot be Paused Stopped or Stored in the Fully Locked mode LxT Manual Fully Locked 12 7 12 8 To unlock the LxT press the A TOOLS key 5 0 00 38 1 gS gt Date 2006 Mar 06 16 33 51 This instrument has been Unlock Enter 4 digit code Press the Tools key to UNLOCK FIGURE 12 9 Unlock The key or the Right or Left Softkey may also be used The CY CH O and 2 keys are used to enter your 4 digit code then press the r key The Model LxT is unlocked and all functions are available to the user Fully Locked LxT Manual
35. 8 1 Time History 9 1 Data Explorer 10 1 System Properties 11 1 Lock Unlock the LxT 12 1 Calibration 13 1 Recommended Calibrators for Use with LxT1 and LxT2 13 3 About 14 1 System Utilities 15 1 LxT Hardware 16 1 Keypad HardkeySs co ociosas cuen ddr ia 16 4 Parameters Measured 17 1 Sound Level Metrics Measured 17 3 Sound Exposure Metrics Measured ooocccccccccoccccccnccnonccnnnncnnos 17 5 Memory Utilization 18 1 Standards Met by LXT ona tii tie A 1 EXT Main Characteristics callada e ati A 3 General Specifications ccccccceeeccccceeeeeeeeneeeesseeeeseeeeeees A 4 Power Supply Specifications nnannnnnnnneeeeeeeeeereernr rnnr nenene A 5 AC DC Output Specifications Eege EE A 5 iv 1i Internal Battery Operating Lutetme eere A 6 Memory Retenciones mel meas A 6 Physical Characteristics ceba A 6 Resolution Specifications cceccceeceeeeceeeeeeeeeeesseeeees A 7 Frequency Weightings Larson Davis A 7 LxT Performance Gpechfcatons nenene A 9 Sound Level Meter Specifications 0nnnnnnnnnneeeeeeeeeeeeeennne n A 10 Noise LxT1 PRMLxT1 with 377BO2 cooooccccccccccccccccccccnnncnnnnno A 28 Noise LxT1 with PRMLxT1L and 377B02 ooooccccccccccccccnnnnnns A 29 Noise LxT2 PRMLxT2 with ZO A 30 Noise LxT2 PRMLxT2L with ZO A 31 EXE PVG Mp Sa A 32 Output COMO iaa a A 34 ere gen te EE A 39 Input CONS nai at dia A 43 Optional EE A 44 Mput eine tel EE A 48 Bleu EEN A 49
36. A ee ee ee 14 5 V MIDEN 0 a E A EENEN ONEEN ENE EENE A e A D 22 Views Changiga arier n as ade ois ha ot a R e e e eda 3 5 Voice Apnnotaton NEE casas sasbeussencvsnnendenvashoesbacnasbredeboasnctetoensetestenenensanassdnasedys 3 20 VOICE RECO eiii oe ee Eeer ee ees Ed 3 20 8 2 Voice Recording Control RTE 8 1 Playback vii dt ake 8 4 Ri aci 8 3 VOICE RECO iii A A A A Ae 8 2 Voltage EE 5 7 W Warranty neten e B 1 E 1 Wavelength I Glossary o Path a e ee EE Ee See D 22 Wavenumber NS D 23 Weighting E UE D 10 Er D 22 LxT Manual a 13 a 14 LxT Manual
37. C 14 to 122 F operating range to 60 C 140 F Humidity Sensitivity 0 05 dB from 0 to 90 RH non condensing at 40 C 104 F Dimensions 12 7 mm diameter x 73 mm length 0 50 dia x 2 88 length Microphone Thread 11 7 mm 60 UNS 0 4606 60 UNS A 42 Technical Specifications LxT Manual Cable Driving Capability LxT SLM 1 Vrms output signal To 20 kHz with 200 61 m cable All values are at 23 C 50 RH 7 5 Volt supply 3 m 10 cable and equivalent microphone of 18pF unless otherwise stated Output Connector Switchcraft TASM 5 Pin male Pin Signal 1 Signal Ground 2 Signal Output 3 Power Supply 7 Volts 4 Preamp sense 5 No Connection Shell Connect to preamp housing Table A 22 Input Connector Compatibility Use with ACO 7052 or any Y electret microphone having about 20 mV Pa sensitivity and meeting the mechanical requirements of IEC 61094 4 It can be used with either the Larson Davis ADP043 or ADP008 adapters for 1 4 or 1 electret microphones LxT Manual Technical Specifications A 43 Optional Accessories EXCO10 EXC020 EXC050 EXC100 ADP005 Extension cable 5 pin Switchcraft male to 5 Pin Switchcraft female 10 feet long Extension cable 5 pin Switchcraft male to 5 Pin Switchcraft female 20 feet long Extension cable 5 pin Switchcraft male to 5 Pin Switchcraft female 50 feet long Extension cable 5 pin Switchcraft male to 5 Pi
38. CAL200 94 0dB 1kHz O LD CAL150 114 0dB 1kHz O 114 0dB 1kHz FIGURE 13 2 Calibrate Page The LxT automatically switches to C weighting and Fast detector response for calibration The Fast detector response reduces the stabilization time required before calibration After calibration the LxT returns to the original frequency and time weighting set by the user On the Calibrator section of this page there is an area to enter information about a calibrator and a list of calibrators The user may select a calibrator from the list or enter new information about a calibrator 13 2 Calibrate LxT Manual Calibrator Recommended Calibrator Table 13 1 Recommended Calibrators for Use with LxT1 and LxT2 lists the sound level calibrators which Larson Davis recommends for calibrating the Lxtl and LxT2 When using a 1 4 microphone the adaptor ADP024 a 1 4 microphone adaptor for the 1 2 opening in the CAL150 and CAL200 calibrators is also required Calibrator Instrument EN ovr Output Frequency Precision CAL200 LxT1 LxT2 Class 1 94 114 dB 1 kHz CAL150 LxT2 Class 2 94 114 dB 1 kHz Table 13 1 Recommended Calibrators for Use with LxT1 and LxT2 Calibrating the LxT1 and 377B02 microphone Many users find that using the nominal calibrator pressure level without corrections for temperature and static pressure provides sufficient accuracy for engineering purposes However for standard w
39. Customer Satisfaction C Index FIGURE 1 1 Bookmarks Bookmark E E E E El E CR P 2 a is F 7 al AE amp o in D j 5 t C a Gd E E E E H In the unexpanded view bookmarks lists the names and page numbers of chapters and appendixes in order of appearance as well as the Table of Contents and the Index To close bookmarks simply left click the tab once more For any entry if there is a within the rectangle to the left there are sub entries which can be displayed upon expanding the tree by clicking the rectangle For example clicking the to the left of any chapter will expand it into major headings and by clicking all the symbols the complete tree for that chapter will be shown In the following figure we can see the entry Measurement Setup completely expanded Special Features of the Electronic Version LxT Manual Click to Display a Page Return to Previous View There are several methods to return to a previous view These methods differ in the various version of Adobe Reader Refer to Help in your version of Adobe Reader L g L List of Tables L Introduction L First Use Overview L Basic Measurement Setup 0 Measurement Properties Screen L Accessing the Measurement Properties Screen L Settings In Use Message Setup Pages L General Page D SLM Page L Frequency Weighting L Ti
40. Davis Inc LD guarantees Total Customer Satisfaction If at any time you are not completely satisfied with any LD product LD will repair replace or exchange it at no charge except as otherwise provided in this Limited Warranty The employees of LD strive to provide superior unmatched customer service Should you find yourself dissatisfied with any LD product for any reason consult a LD Application engineer or local representative distributor to discuss your situation B Purchase Price Refund Limited Warranty LD warrants to the original purchaser the Buyer that unless otherwise expressly specified in writing by a LD officer all LD products shall be free of defects in material and workmanship for a period of two 2 years from date of original purchase In furtherance of LD s commitment to Total Customer Satisfaction LD will for a period of one 1 year from date of original purchase refund 100 of the customer s purchase price for any LD product with which the buyer is not completely satisfied subject to the exceptions contained in Paragraph J of this Limited Warranty The option of a refund may be selected during this one 1 year period in lieu of repair replacement or exchange of the product Extended Labor Warranty In furtherance of LD s commitment to Total Customer Satisfaction LD offers an extended labor warranty of one 1 year on all products calibrated or certified by a factory technician at any time or from time to
41. Electrical Impedance Adaptor 1 11 Exchange Rate A er ee A A ASR RAN RE D 8 Exchange Rate Factor GI OSSAEY sissies Hate A ee ha EE D 8 a 4 LxT Manual Exposure Factor Oe gouereg eg ege EES te dae Nae deene dee ni D 8 F Feat Field eme ii eaten tal Geeta aon del GAT Nee ees D 8 AN COUSLIG SE e SN SE RA D 9 A ete een eI ed Stel ee D 9 FACING Sree cesses eects shee eege eege a 1 7 Eeer enee ee tem 15 2 Filters 111 13 Octave Filter Shapese 3 2 00 a A 11 Free field a D 9 Frequency Band Pass Filter Gonner ti a E D 9 EOT aA E E E AE E AE E E E AEA E S D 9 A nr E EE E E A E E E ia D 9 Frequency Spechrum cccccccccsecsseceseeseeseesenscseeseeecsecseesesseesecseesessesseeeeeeesseseees D 21 Frequency Weighting sneen eens ha dei RR aie 4 5 G EI EE UE 5 23 H HOST AAA Rete 1 12 Us di A E 8 3 Headset Output ico coccion canada nocsiadannc cdo coda caste ssassiscdisssseloetestetscsstacsideshetestucs 11 12 I Industrial Hygiene Dosimeter AAA E 5 14 MEA diria 5 16 E AO 3 11 Integrated Level Calculations conc roncrronnonooos C 1 Dose Calcula A ee C 5 Equivalent Continuous Sound Level C 1 ene We C 5 Sound Exposure sed SEENEN EEN C 8 EE EE C 2 Integration ci Aa Widnes nee 4 6 Intrinsic Safe EE ii dia 2 6 LxT Manual a 5 L EU e EA E 5 4 e ee E 5 3 LACG 1S tes fei cites trite he ee o a eo 5 3 LANGUAGES EE 11 9 LAS ni a A E EA ca cn OER REED 5 3 5 4 5 9 Y ET EN A RR E EM EAEE A RA AAAA AS NA 5 9 LAS UE De A a DS 5 10 LAS E
42. Sample 3 of 11 set Le 100 ET 60 Use and oo keys to display data for points later or earlier in the time history sequence FIGURE 9 10 1 1 Octave Leq Spectrum Time Sample 2 Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 Moving the Frequency Cursor LxT Manual The bar graph display is a 1 3 octave Leq spectrum with the cursor located at 1 kHz The level in that frequency band is displayed numerically as 88 7 dB Because in our setup we also selected to log OBA 1 3 max and OBA min in addition to OBA Leg there are curves for all three values in the display and numerical values are displayed for all three at the cursor frequency From the annotation we can see that this spectrum corresponds to the 3rd time interval and that data have been stored for 11 time intervals Use the and keys to move the cursor to higher or lower frequencies respectively in order to read the parameter value at different frequencies Time History Display 9 13 Changing the Time Interval Value Use the C and amp keys to increase or decrease the time interval for the data displayed For example pressing the C key three time will increase the time interval by three steps producing the display shown in FIGURE 9 11 Se T 91 0 dB 54 5 dB 6 11 2006 Jun 08 15 18 56 Enter gt By Time FIGURE 9 11 1 1 Octave Leq Spectrum Time Sample 5 Returning to Ti
43. Serial Number 2440346 oe 4 0 dB Mic 1584 89 Hz Mic 3162 28 Hz Mic 6309 57 Hz Mic 12589 25 Hz FIGURE A 16 LxT with 7052 Microphone 1584 89 Hz 3162 28 Hz 6309 57 Hz and 12589 25 Hz Noise Levels The noise of the LxT includes contributions from the following components e Instrument and preamplifier e Microphone In the following sections the noise levels for each component and the total are presented as a function of frequency LxT Manual Technical Specifications A 27 LxT1 PRMLxT1 with 377B02 17 Nov 05 377B02 PRMLxT1 and LxT1 Noise LxT1 8 PRMLxT1 377802 LxT1 PRMLxT1 and 377B02 Frequency Noise Noise Noise Hz dB SPL dB SPL dB SPL 6 3 18 6 21 2 18 6 7 9 18 0 20 2 18 0 10 0 17 5 19 2 17 5 12 6 17 0 18 2 17 0 15 8 16 9 17 2 16 9 20 0 16 4 16 2 16 4 25 1 16 3 15 2 16 3 31 6 15 5 14 2 15 5 39 8 14 2 13 2 14 2 50 1 12 8 12 2 12 8 63 1 11 6 11 2 11 6 79 4 10 6 10 2 10 6 100 0 9 9 9 2 10 0 125 9 9 7 8 2 9 8 158 5 9 5 7 2 9 6 199 5 9 2 6 2 9 3 251 2 9 2 5 2 9 4 316 2 9 2 4 2 9 4 398 1 9 7 3 2 9 9 501 2 10 0 2 6 10 2 631 0 10 6 1 8 10 8 794 3 11 3 0 8 11 6 1000 0 12 1 0 1 12 4 1258 9 12 9 0 8 13 2 1584 9 13 8 1 5 14 0 1995 3 14 8 2 5 15 0 2511 9 15 7 3 2 15 9 3162 3 16 6 3 9 16 8 3981 1 17 5 4 4 17 7 5011 9 18 5 4 9 18 7 6309 6 19 5 5 1 19 7 7943 3 20 5 5 1 20 6 10000 0 21 4 4 8 21 5 12589 3 22 5 4 3 22 6 15848 9 23 5 3 4 23 5 19952 6 24 4 21 24 4 Awt 29 1 16 7 29 3 Cwt 28 9 1
44. Voice Recording The user is instructed in the process of recording reviewing and saving voice messages Chapter 9 Time History Describes the use of the optional firmware LxT LOG for measuring time history data Chapter 10 Data Explorer Learn to use the Data Explorer to view stored data files load settings from a saved data file and other operations Chapter 11 System Properties A discussion of instrument related functions Chapter 12 Lock and Unlock The LxT A discussion of the various scenarios to lock or unlock the LxT and the interaction with running a measurement Chapter 13 Calibration Describes the process of calibrating an LxT Chapter 14 About A look at basic LxT system related information Chapter 15 System Utilities A description of the utilities available within the LxT Chapter 16 Hardware A description of the major hardware related features of the LxT Chapter 17 Parameters Measured An overview of the many parameters measured and recorded by the LxT Chapter 18 Memory Utilization Presents formulas to determine the memory used when saving parameters to internal memory About This Manual LxT Manual Appendices e Appendix A Technical Specifications Provides a listing of acoustic electronic environmental and physical characteristics of the LxT e Appendix B Measuring to 1EC61672 1 Provides specifications and information specifically required to appear in the manual by
45. a a E iio 11 5 Preferences Page cc cccscssscsssseceececesecceccencneneaeeneeseeeecseensneensneneseess 11 8 Language Preferences icccccononioncocolocionodicid cece ete eerste eee 11 9 Decimal Symbol Preferences ococococococccnnencnnnenennnnionncnncannnernacccnas 11 10 Date Format Preferences ccseceeeeeeeeeeeeeeeeeeeeeeseeeeseeeeess 11 10 Auto Store Preferences AAR 11 11 Jack Function Preferences AAA 11 12 ili iv USB Storage Preferences cocoocccinoocococococonenoronnenencnnennndnnnnnn antenna 11 13 Display Start Options aimara dnd canard 11 14 Display Tab Page Options cross 11 15 Ne TRUE 11 15 Overall Page Displays ones 11 16 Session Log DISPARA 11 16 Time History DiSplayS oocciccccccccccccccccccccconnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnns 11 16 Display Set to Appear or Hide ccccceceeecceeeeeeeeeeeeeeeeeeeseeeeees 11 17 Lock Unlock the LE 12 1 Control GT EE 12 1 LOCK PAGO e do o o 12 2 Lock Mode Listo a a A a e 12 2 eier 12 4 Lee gel e EE 12 5 Allow Gal Check BOX EE 12 6 Bully Locked de ed o 12 6 Are ge BEE 12 7 WI OG Ke ron a a SS de e e oh eR eet e 12 8 Locked with Auto Store or Manual Store sseeeeeeeeeeeeees 12 9 AU SOTO ic 12 10 Le Deen We e e e O ai 12 11 Manual Store When Locke 12 12 Locked with Calibration Pemmtted 12 14 GC aliDVatiOn ecnin aaia atin EaR 13 1 Control ln EE 13 1 Calibrate Page ico estas odecnceeecabigesisnsqsaads bide st c
46. are five drop down list fields and one scrollable value field on the Power Page These fields are selected and modified as discussed in the previous sections Auto Off time is the duration of time the instrument will stay on when no activity is occurring button presses running a measurement USB communications etc Pressing the ON OFF key will return the instrument and the display to the state 1t was in when the Auto Off time expired If the instrument is connected to external power this feature is ignored Power 11 5 Power Save Time 11 6 Available durations are e 5 min e 10 min e 30 min e 60 min es Never The default value is Never The duration selected in the Power Save Time field sets the length of time the instrument will continue to measure sound level and update the display when the instrument is not in run mode and no other activity is taking place such as key presses or USB communication At the end of this time the LxT enters a power save mode In this mode the sound pressure level is shown as To exit this mode press the EZ RUN PAUSE key There will be a few seconds delay before the instrument starts recording data If the LxT is connected to external power this feature is ignored Available durations are 5 minute 10 minute 30 minute 60 minute and Never The default is Never Power LxT Manual Backlight Time Backlight Mode
47. becomes less important The rate at which older data are made less influential is expressed by the constant T The larger is it the slower the decay factor reduces and the slower the response of the system to rapid changes These are standardized into three values called Time Weighting See the values below Fixed Average The averaging process is over a fixed time period The equation for it is The sound pressure is squared and averaged over a fixed time period Unlike the moving average the sound pressures in all time intervals are equally weighted The logarithmic form of sound pressure It is also expressed by attachment of the word decibel to the number The logarithm is taken of the ratio of the actual sound pressure to a reference sound pressure which is 20 MicroPascals u Pa There are various descriptors attached to this level depending on how the actual sound pressure is processed in the meter Instantaneous The time varying reading on a meter face on in a meter output due to changes in the sound pressure The reading will depend on the time weighting applied The fundamental relationship between the two is logarithmic rms 20 L 7 201081 Prms 7 pio Po Glossary D 19 where pg is the reference sound pressure of 20 uPa The square of the sound pressure is a power like quantity that can be expressed in the original form of the level definition 2 Prms 2 2 sed 1 L BEA 2 Prms 7 Dol f Po Sound
48. cero is BORO 4 3 General e EN 4 4 SEM PAE oo ls 4 5 DOSIMNGIOR dina A AAA AAA a 4 7 Predefined Dose Setups ccsseeeeeeeeeeeeeeeeeeeeeeeeesseeeeeeesess 4 9 Sx Gee aha Bee eReader ee eRe id 4 10 Exchange Rate Listar ia 4 11 n BIS ie EE 4 12 iii i OBA Bandwidth tegt 4 14 OBA Frequency Weighting Menu 4 14 OBA Max Spectrum Mode Menu 4 15 Rene We CH 4 16 PRU MOG Ee EE 4 17 Manual Run Mode EE 4 18 Timed Stop Run Mode date deed 4 18 Entering Time in Timed Stop Run Mode oocccccccccccccccccccccnnnnnccnncnnnn 4 19 Stop When Stable RUN Mode occcccccccoocccnccccccocccnononononononnnnnnnnanonnos 4 19 Taggers PAT a 4 20 Exceedance Event Example 4 21 AppIy e Le 4 22 Basic Data Display cc cssceeeeeeeeeeeeeeeeeseeeeeeeees 5 1 Tabbed Page e 5 2 Live Page Section EN RE 5 3 Live Page Section WEE 5 4 Live Page Section Bici A A iA 5 5 Live Page Section Asc 5 6 lve Page Section E 5 7 Overall Page Section Tias 5 8 Overall Page Section 2 5 9 Overall Page Section 3 5 11 Overall Page Section A 5 13 Dosimeter 1 amp 2 Display Sections 5 and pe 5 14 Overall Page Section Tiida 5 15 SEA Display Section EEN 5 16 Overall Page Section 8 5 17 Overall Page Section 10 5 18 Overall Page Section 1 5 19 Overall Page Number of Measurements by Type Section 12 5 20 Equivalent Page Section 13 5 21 Session Log Page suse duckie enna eee a 5 22 Graph Menu Disp A
49. ee hace n 2 6 Battery Power LxT Manual a 1 Battery TYPE geste gereest do 11 8 Battery Voltage ssc EES EE 5 7 B okmarkS eise Seege EA OH ae ee eae 1 3 A i E RE E ER RR R E e EERE E ERE 1 4 Display EE 1 5 Expanding ee onini A EE ETE E E 1 4 RI EE 1 3 Return to Previous Niewt NEEN aia 1 5 C Cables AC DC Outputs a dot sage oh eed atta el ater el ENORA 1 11 Direct Input vecna ee es ee EE A 1 11 Microphone Extension 1 11 USB a A ese a ek SR ee tt 1 11 Galculations ease gesiess C 1 O N e H i eg Set deeg a eR even 3 20 13 2 Calibration see se ee go eege stata usa Mees 13 1 SEH 13 2 Gali E 13 3 GO Te Dr ei E AO RN RE OE OE 13 10 Control geen 13 1 Ego eege ee ee 13 9 Calibration History 2000 00 ceecssesceseeseescesceseseeeecsecsecsecsensecsecseneseecsseneeesneeas 13 9 alter ois x css E et A ees 13 3 Recommended EE 13 3 Changing Data Pages cio Se 3 15 Changing ViewS lt 22 23 30 2 20 lt c ocisse ai 3 5 Check Battery Power eigene AE A RA SE eaaa 3 12 Close beet we Sets 3 8 CNEL iii A ee Saal tied ee Mite C 11 Community Noise Equivalent Level 0 0 ccc csecsseseesecseeeceseeseeseeeeneeneees C 11 Complete arm Action vico ii Abaco sein EE Ee 3 11 Continue a RUN ec ecceccccceseececeseeeesecssescesesaeeseescssessesecsecsecsecsessecseceeeeeecseeneeeeneeas 3 11 Contrast Como e Re to se oe ce o 3 12 Control Page sect tt dan ies an dd wl eo eal ld a Ne Bests 4 16 Control Panel 15 1 erh S
50. from 0 to 90 RH non condensing at 40 C 104 F Dimensions 12 7 mm diameter x 73 mm length 0 50 dia x 2 88 length Microphone Thread 11 7 mm 60 UNS 0 4606 60 UNS Cable Driving Capability LxT SLM 1 V rms output signal To 20 kHz with 200 61 m cable All values are at 23 C 50 RH 7 5 Volt supply 3 m 10 cable and equivalent microphone of 18pF unless otherwise stated A 38 Technical Specifications LxT Manual Output Connector Switchcraft TASM 5 Pin male Pin Signal 1 Signal Ground 2 Signal Output 3 Power Supply 7 Volts 4 Preamp sense 5 No Connection Shell Connected to preamp housing Table A 21 Input Connector Compatibility Use with Larson Davis 377B02 or any Y electret microphone having about 50 mV Pa sensitivity and meeting the mechanical requirements of IEC 61094 4 It can be used with either the Larson Davis ADP043 or ADP008 adapters for 4 or 1 electret microphones In the interest of constant product improvement specifications are subject to change without notice Larson Davis provides a complete line of acoustic measurement tools including dosimeters sound level meters real time analyzers preamps calibrators and microphones LxT Manual Technical Specifications Larson Davis A 40 Preamplifier Model PRMLxT1L Serial Number 0102 Certificate of Electrical Conformance Frequency response of this model PRMLxT1L pr
51. hidden Softkey Selection of System Properties Pages a Device Preferences Displays FIGURE 3 10 System Property Pages Lock For a detailed description of the Lock feature see Chapter 12 Lock Unlock the LxT on page 12 1 LxT Manual The Right and Left Softkeys are used to scroll between System Property Pages Lock permits the LxT to be configured such that certain keys are locked so their functionality cannot be utilized Tools Screen 3 19 Calibrate For a detailed description of the Calibrate is used to verify and adjust the calibration of the calibration procedure see Chapter LxT prior to a measurement 13 Calibration on page 13 1 Voice Recorder For a detailed description of the A method to allow voice annotation of the data is described voice recording feature see Chapter in Chapter 8 Voice Recording on page 8 1 8 Voice Recording on page 8 1 About For a detailed description of the The About Pages provide the user with information specific About Pages see Chapter 14 to this instrument such as serial number options etc These About on page 14 1 are single section pages There are four About Pages About shows information such as serial number and firmware revision e Standards lists the standards that the LxT meets e Options shows the options that are available in this instrument e User user entered instrument identifi
52. level measurements so there is no need to select a range as part of making a measurement Data Display See Chapter 5 Overall Page on page 5 7 The Live Display provides a running sound level measurement whether or not the LxT is actually performing a measurement while the Overall Display provides the measurement actually being made Select the Overall Display in order to observe the measurement in progress Press the JE RUN PAUSE key to start the measurement which will start the run clock and initiate the measurement and display of overall data The measured data are available for display from the Overall View These data are distributed over thirteen sections with the LxT LOG and LxT OBA options Use the 7 and CH keys to change sections The first two sections from the top present basic sound level parameters as shown in FIGURE 7 6 and FIGURE 7 7 7 8 Performing the Measurement LxT Manual Measurement Duration 0 00 18 0 i LxT_Data Leq Running SPL Laseq 72 2 dBEJ Las 33 5 dB Date and Time of Initiation of Measurement FIGURE 7 6 Leq and Running SPL The two digital displays present the Leq value 72 2 dB and the running SPL 33 5 dB Both of these were measured using A weighting and Slow detector as indicated by the AS The duration of the measurement is indicated at the top of the display and the data and time that the measurement was initiated are indicated at the bottom of the display Th
53. logarithm is the root mean square frequency weighted sound pressure level over the averaging time interval T When a frequency weighting other than A is used the frequency weighting used shall be included explicitly in the title and the formula of the quantity for example equivalent continuous C weighted sound pressure level 1 2 Ler Leer 201g 14 ree ue P dB t If no frequency weighting is used the quantity is simply called equivalent continuous sound pressure level The Larson Davis LxT calculates many time integrated levels or time weighted averages TWA based on different parameters and time intervals They are all designed and programmed to perform the equation specified in IEC 61672 1 with allowances for the following A C and Flat frequency weighting characteristics Various interval times both fixed interval TWAs and variable interval event TWAs Exchange rates or doubling rates can be entered that effect certain TWA measurements Certain TWA measurements include a programmable threshold with only levels above this threshold contributing to the measurement Integrated Level Calculations Model 831 Manual No attempt is made to meet the IEC 61672 1 requirement to title the TWA by frequency weighting and time interval within the analyzer s display or report system The Frequency Weighting and Time Interval are both displayed in the same view to meet this requirement The following figure indica
54. of one year is recommended but this can be lengthened or disabled depending on applicable requirements 13 10 lt gt 0 00 00 0 i Calibrate Tool D History Certification Performed 2006 Jun 15 Due 2007 Jun 15 Factory Certification Larson Davis Inc 1681 West 820 North Prowo UT 84601 716 926 8243 Certification Interval Certification 15 Days e Reminder 15 Days 1 Year Y 4 Close FIGURE 13 7 Certification Page The Certification Page shows the date of the last certification and the due date for the next certification Information about the calibration facility typically Larson Davis Inc is displayed in the middle of the page The user has the opportunity to set the calibration interval and a calibration reminder Use the C and keys to highlight the desired drop down list box and press the D key A list of available times will appear Using the C and US keys highlight the desired duration and press the ED key Available Certification Intervals are 1 year 2 years 3 years and 4 years Available Certification Reminder times are 15 days and 30 days Certification LxT Manual CHAPTER About The About Pages give summary information concerning the instrument available options and instrument identification Control Panel About To activate the About Pages press the A TOOLS key Use the C AUT or keys to highlight the About icon as shown in FIGURE 14 1 Control Panel
55. speed data download analysis and reporting Multi tasking processor allows measuring while viewing data or transferring data Data Secure Feature saves data to permanent memory every minute AC DC outputs to recorder Long battery life 16 hours continuous measurement Field upgradable firmware keeps instrument current with the latest measurement features via ROM disk upgrades Two year limited warranty Table A 2 LxT Main Characteristics LxT Manual Technical Specifications A 3 General Specifications Reference level 114 0 dB SPL Reference level range Single large Range for SLM Normal for OBA option Reference frequency 1000 Hz Reference direction 0 is perpendicular to the microphone diaphragm Temperature lt 0 5 dB error between 10 C and 50 C Storage temperature 20 C to 70 C Humidty lt 0 5 dB error from 30 and 90 relative humidity at 40 C Equivalent mic 16 pF for Larson Davis 1 2 microphone impedance Range level error OBA lt 0 1 dB relative to the reference range option Digital Display Update Four times per second 0 25 sec between Rate updates First display indication is available 0 25 seconds after initiation of a measurement Nominal Drift of Within limits 1 7 to 6 0 second day Displayed Time Effect of an extension none up to 200 feet cable EXCXXX on calibration
56. the Center Softkey labeled Menu press the key to highlight Settings and press the Get key The Measurement Properties Screen will now be displayed with the page selected that is most appropriate for the data display from which it was activated If the Blaze or LxT Utility software is already connected to the LxT when an attempt is made to access the Measurement Properties Screen the display shown in FIGURE 4 1 Settings In Use By LxT Utility Message will appear Settings in use by PC Continue 36 1 dB 3 317 gt 2006 Apr 21 13 55 16 Enter gt By 1 3 Frequency J FIGURE 4 1 Settings In Use By LxT Utility Message This warns the user that accessing the Measurement Properties Screen will cause setup changes which had been made using the LxT Utility during this session to be lost Measurement Properties Screen LxT Manual Setup Pages Only a few of these horizontally arranged tab pages three in Figure 4 2 can be seen at one time To see those off screen to the right use the Right Softkey beneath the display To scroll back to the left use the Left Softkey beneath the display LxT Manual To continue and access the Measurement Properties Screen highlight Yes and press the Grr Key To cancel the attempt to access the Measurement Properties Screen highlight No and press the Gre key Depending on the firmware options loaded in the LxT there may be as many as ten different setup pages in the M
57. type of sound source is significant Since the wavelength varies with frequency See the definition of Wavelength the distance will vary with frequency The most common example of a near field is driving an automobile with an open window As you move your ear to the plane of the window the sound pressure level builds up rapidly wind noise since most of the pressure changes are to move the air and very little of it compresses the air to create sound Persons not far way can hardly hear what you hear The acoustic near field is characterized by pressures that do not create sound that can be measured in the far field Therefore measurements made here are not useful in predicting the sound levels far way or the sound power of the source Geometric Near Field The distance from a source of sound is less than the largest dimension of the sound source In the Glossary LxT Manual Noise Noise Dose D LxT Manual near field effect of source geometry is significant Sound sources often have a variety of specific sources within them such as exhaust and intake noise When in the near field the sound of a weaker but close source can be louder than that of a more distant but stronger source Therefore measurements made here can be used to separate the various sources of sound but are not useful in predicting the sound levels and sound spectrum far from the source Typically it is unwanted sound This word adds the response of humans
58. use a wind screen over the microphone to reduce the effect of wind noise 3 Mount microphones so their body is not subject to vibration particularly in direction at right angles to the plane of the diaphragm 4 Keep microphones away from strong electrical fields A microphone measures forces not pressures We would like the microphone to measure sound pressure force per unit area instead of sound force If the pressure is applied uniformly over the microphone diaphragm a simple constant the diaphragm area relates the two but if the pressure varies across the diaphragm the relationship is more complex For example if a negative pressure is applied on one half the diaphragm and an equal positive pressure is applied to the other half the net force is zero and essentially no motion of the diaphragm occurs This occurs at high frequencies and for specific orientations of the microphone Rules 1 Do not use a microphone at frequencies higher than specified by the manufacturer to increase the frequency response choose smaller microphones 2 Choose a microphone for free field or random incidence to minimize the influence of orientation A microphone influences the sound being measured The microphone measures very small forces low level sound can run about one billionth of a PSI Every measurement instrument changes the thing being measured and for very small forces that effect can be significant When sound impinges directly on a mic
59. used to select general instrument formatting 3 0 00 08 1 A485 System Properties db Preferences 4 Language English Decimal Symbol Period e SIS SIS l 4 4 Date Format Auto Store Jack Function C DC e USB Storage O Reset Prompting O Takt Maximal Data d Close FIGURE 11 6 Preferences Page Use the CI and gt keys to highlight the preference to be selected and left click the key to view a list of options 11 8 Preferences LxT Manual Languages The LxT supports the following languages e English e French e German e Italian e Portuguese e Spanish English is the default language Use the 7 and US keys to highlight the Language field and press the as key to obtain a listing of the language choices as shown in FIGURE 11 7 Language English Decimal Symbol AMEN Date Format Auto Store Jack Function USB Storage FIGURE 11 7 Language Preferences Use the CJ and keys to highlight the desired language and press the key to make a selection LxT Manual Preferences 11 9 Decimal Symbol Date Format 11 10 The LxT supports two formats for the decimal symbol e Period e Comma Use the CJ and keys to highlight the Decimal Symbol field and press the a key to obtain a listing of the choices as shown FIGURE 11 8 Comma 4 Period FIGURE 11 8 Decimal Symbol Preferences Use the CJ and E keys to highlight the desired symbol and press the key to make th
60. was met If a duration is set the measurement would run for the duration specified and then continue until the stability condition was met For each use the J and keys to highlight the desired data field and press the key Use the and keys to position the cursor and the 7 and keys to set the digit for that position When the desired value has been entered press the key Run Modes 6 5 Continuous Run Mode Daily Auto Store 6 6 Run Mode r Daily Auto Store FIGURE 6 7 Continuous Run Mode The run mode is indicated at the top as Continuous The Continuous Run Mode is very similar to the Manual Mode except for the Daily Auto Store feature described below The measurement will continue until the measurement is manually stopped When the Auto Store check box in the Daily Section is checked daily measurement reports for 24 hour time periods beginning at a user specified time will be automatically stored assuming that the measurement time period encompasses at least one 24 hour time period as programmed Use the 7 and keys to highlight the Auto Store field and press the key to insert a check mark repeat the procedure to remove a check mark Run Modes LxT Manual Single Block Timer Mode LxT Manual When the check mark is inserted a data field will be opened as shown in FIGURE 6 8 to define the start time for the 24 hour time period to be used for the report L x Auto Store Time 1
61. without notice Larson Davis provides a complete line of acoustic measurement tools including dosimeters sound level meters real time analyzers preamps calibrators and microphones LxT Manual Technical Specifications O Preamplifier Model PRMLxT1 Serial Number 0163 Larson Davis Certificate of Electrical Conformance Frequency response of this model PRMLxT1 preamplifier was tested at a level of 13 858 Vrms with 18pF microphone capacitance and driving a short cable Output level at 1kHz is 0 9442 Vrms 0 499 dBV uncertainty 0 045 dB Output is 3 511 V DC uncertainty 0 001 Results are displayed relative to the level at 1kHz 0 5 50 100 200 501 1000 1995 5012 10000 19953 50000 100000 Frequency Hz Measured dB Uncert dB Tolerance dB Freq Hz Measured dB Uncert dB Tolerance dB 01 02 05 06 07 08 08 08 09 09 09 09 10 10 he 10 10 10 E 10 10 10 ovcoocoooconconon n oc p p o p o cocoo ovcoocooocononcon o o p c ocooo 126000 Noise floor data 1kHz 1 3 Octave 0 16 uV 15 7 dBuV uncertainty 0 47 dB Flat 20Hz 20kHz 1 7 uV 4 4 dBuV uncertainty 0 47 dB Awt 1 0 uV 0 3 dBuV uncertainty 0 46 dB Uncertainties are given as expanded uncertainty at 95 confidence level k 2 Technician Ron Harris Test Date 30SEP2005 F
62. 0 LOU A ce Seana aaa teas eee awe ean PS 11 9 Reset Prompte See Pack vite eebe Eege 11 13 R Refresh Files List 10 8 Rename Files ico tb tele ta ENEE ities 10 6 PRESSE ON 3 4 Reset Prompt ici aiii Sedat bac Sebo cab ca dee coa ERO Ocoee bees 11 13 Run Control O E E a 6 6 Daily RTE 6 9 Mantial Stop Mode eseou ere Ae ds 6 3 6 4 SETUP E 6 1 Single Block TINE ii dia 6 7 Stop When Stable E En AA E E T R 6 5 Timed Stop Mode a A a eE A aR 6 10 Without Measurement History oooooococccoccoonoononnnonncnncnononn non connnnn nono non non non nn rn nr nn narrar 6 3 RUN CON a A vote A A a cs 3 4 TE OC 3 35 7 Run Pause Keys ts eit ec a ect el ee at 3 11 S EIERE tte ee am eee tite a e 3 2 3 12 3 14 IR CBR EE 3 12 Measurement Properties 3 12 Power e EE 3 12 LO a o e dee o e e Ml 3 12 Scroll Dat ii iia 3 2 Scrolling Between Sections 3 15 Section indicator coin lidia reads 3 2 SEL Cal ulations oos cia aries CA Session Log Hagen ees ee n EE 5 22 SETUP Key iia is aes eet ee ene icons dE 3 7 BOT U PAGOS EE 4 3 a 10 LxT Manual lu 3 5 7 4 AC 1 12 Bla Ze EE 1 12 Sound Average level lave iii ta D 2 Day night average Jevel E o a nn non rico nn A D 3 Energy average Leg iii ici D 20 RES UE tee Dengen eene ee da D 17 Exposure TV ii AA id D 17 Ex dada D 19 EE D 16 pul is A EE D 20 TniStamtan cous dd ti n D 19 bn EE dd dd en Id ee dad ad D 21 Mowing AA dc D 18 Pres ora ee sola D 18 Sound pressure leve SPLE Lp cit di D 1
63. 0 01 dB kPa If the system is calibrated at 85 kPa for instance then it will be 0 16 dB less sensitive at sea level 101 3 kPa The sensitivity of the 377B02 and LxT varies slightly with temperature also The coefficient of temperature is 0 009 dB C If the system is calibrated at 18 C then it will be 0 04 dB less sensitive at 23 C The Larson Davis 3 Wind Screen has less than 0 05dB effect on the system response at 1 kHz Set the CAL200 level switch to 94 or 114 dB Calibrating the LxT2 and 7052 microphone Many users find that using the nominal calibrator pressure level without corrections for temperature and static pressure provides sufficient accuracy for engineering purposes However for standard work the proceedure described here is recommended 13 4 The CAL200 provides a nominal pressure level of 94 dB or 114 dB The exact levels are printed on the Larson Davis calibration sheet that came with the calibrator When using a free field microphone the pressure level at the microphone diaphragm will be slightly different Thus a free field correction of 0 12 dB should be applied to either of these levels If the calibrator and instrument are near room temperature 23 C and near sea level 101 3 kPa then no other corrections need to be made If the calibration sheet for the CAL200 indicates 113 98 dB for it s level when set to 114 dB then set the Cal Level in the LxT to 113 86 dB and 1000 Hz When the microphone an
64. 0 23 38 hh mm ss FIGURE 6 8 Auto Store Report Start Time Use the O key to highlight the data field below and press the Gr key Use the and 2 keys to position the cursor and the and keys to set the digit for that position When the desired value has been entered press the key Use the O key to highlight the data field below and press the Gr key Use the and 2 keys to position the cursor and the and keys to set the digit for that position When the desired value has been entered press the key Run Mode Single Black Timer e Start Time End Time FIGURE 6 9 Single Block Timer Run Modes 6 7 6 8 The run mode is indicated at the top as Single Block Timer This mode is used when a single measurement is to be made starting at a user defined date and time and ending at another user defined date and time The Start and End dates and times are set using the data fields provided in the lower section of the menu To set these parameters use the CI and CH keys to highlight each field and press the eet key For the parameter fields requiring numeric entries use the technique described in section Entering Run Time on page 6 4 For the months pressing the key will open a the menu shown in FIGURE 6 10 FIGURE 6 10 Selecting Months for Single Block Timer Run Modes LxT Manual Daily Timer Mode LxT Manual Run Mode Start Time End Time 01 3an_ v 2006 01 3an_ org
65. 00 0 0 16 1 0 2 0 5 0 5 1 0 Table A 10 Frequency Weightings Larson Davis LxT Manual Technical Specifications A 7 Frequency Weightings 160 158 50 0 0 13 4 0 1 0 2 0 5 1 0 200 199 50 0 0 10 9 0 0 0 2 0 5 1 0 250 251 20 0 0 8 6 0 0 0 2 20 5 1 0 315 316 20 0 0 6 6 0 0 0 2 0 5 1 0 400 398 10 0 0 4 8 0 0 0 2 0 5 1 0 500 501 20 0 0 3 2 0 0 0 2 20 5 1 0 630 631 00 0 0 1 9 0 0 0 2 0 5 1 0 800 794 30 0 0 0 8 0 0 0 2 0 5 1 0 1000 1000 00 0 0 0 0 0 0 0 2 0 5 1 0 1250 1259 00 0 0 0 6 0 0 0 2 0 5 1 0 1600 1585 00 0 0 1 0 0 1 0 2 0 5 13 2000 1995 00 0 0 12 0 2 0 2 0 5 13 2500 2512 00 0 0 13 0 3 0 2 0 5 1 7 3150 3162 00 0 0 12 0 5 0 2 0 5 1 7 4000 3981 00 0 0 1 0 0 8 0 2 0 5 2 0 5000 5012 00 0 0 0 5 1 3 0 2 0 75 2 3 6300 6310 00 0 0 0 1 2 0 0 2 1 0 3 0 8000 7943 00 0 0 1 1 3 0 0 2 1 0 3 3 10000 10000 00 0 0 2 5 4 4 0 2 1 0 3 3 00 12500 12590 00 0 0 4 3 6 2 0 2 15 3 3 00 16000 15850 00 0 0 6 6 8 5 0 3 2 0 3 3 00 20000 19950 00 0 0 9 3 11 2 0 5 2 0 3 3 00 Table A 10 Frequency Weightings Larson Davis A 8 Technical Specifications LxT Manual LxT1 LxT1L LxT2 LxT2L Direct In Measurement A 39 to 140 dB 27 to 118 dB 37 to 139 dB 31 to 126 dB 13 to 117 dBuV
66. 1 5 Components LxT Manual Keypad Softkeys LxT Manual STOP STORE SOFTKEYS Center Right ts RUN PAUSE FIGURE 16 2 LxT Keys The three push button keys just beneath the display on the body of the LxT are called Softkeys Above each Softkey on the bottom of the display is an icon that may contain a label The label indicates the action which will take place when the key is pressed Softkeys are so named because the role of each key can change depending upon how it is programmed as indicated by the label Components 16 3 Hardkeys The ten push button hardkeys have fixed functionalities as defined below The Power button is used to turn the LxT ON and OFF when the Hardware Power Switch on the base of the unit is in the position The Navigation buttons Up Down Left and Right are multipurpose keys used to highlight icons and defined areas on the display make a selection from multiple options scroll through sections of multi section Data Views and to input alphanumeric characters into data fields 16 4 The Enter button is used to implement data entry associated with selections from multiple options or the input of alphanumeric characters into data fields The Run Pause Button is used to initiate and pause a measurement and to con tinue a paused measurement The Stop Store Button is used to stop a measurement and to store a measure ment when the measurement is stopped
67. 10 01 0 03 036 0 10 0 15 1258 90 00 016 0 10 0 10 31 0 02 036 0 10 0 13 1584 90 00 016 0 10 0 10 94 0 01 036 0 10 0 11 1995 30 00 016 0 10 0 10 00 0 01 016 0 10 0 10 2511 90 00 016 0 10 0 10 59 0 00 016 0 10 0 10 3162 30 00 016 0 10 0 10 85 0 00 016 0 10 0 10 3981 10 00 016 0 10 0 10 35 0 00 016 0 10 0 10 5011 90 00 016 0 10 0 10 12 0 00 016 0 10 0 10 6309 60 00 016 0 10 0 10 62 0 00 016 0 10 0 10 7943 30 00 016 0 10 0 10 81 0 00 016 0 10 0 10 10000 00 00 016 0 10 0 10 12 0 00 016 0 10 0 10 12589 00 00 016 0 10 0 10 10 0 00 016 0 10 0 10 15849 00 00 016 0 10 0 10 43 0 00 016 0 10 0 10 19953 00 00 016 0 10 0 10 00 0 00 016 0 10 0 10 25250 00 00 022 0 10 0 10 89 0 00 016 0 10 0 10 31500 00 00 022 0 10 0 10 49 0 00 016 0 10 0 10 39750 00 00 022 0 10 0 10 453 0 00 016 0 10 0 10 50000 00 00 022 0 12 0 12 19 0 00 016 0 10 0 10 63000 00 00 047 0 14 0 14 23 0 00 016 0 10 0 10 79500 00 01 047 0 16 0 16 LL 0 00 016 0 10 0 10 100000 00 02 047 0 18 0 18 19 0 00 016 0 10 0 10 126000 00 03 063 0 20 0 20 Noise floor data 1kHz 1 3 Octave 0 17 uV 15 3 dBuV uncertainty 0 47 dB Flat 20Hz 20kHz 1 6 uV 3 9 dBuV uncertainty 0 47 dB Awt 1 0 uV 0 2 dBuV uncertainty 0 46 dB Uncertainties are given as expanded uncertainty at
68. 10 8 File Name List Select a name from the list and press the Enter key The Rename File will now open again with the name of the file which is to be overwritten in the file name field as shown in FIGURE 10 9 Rename File LxT_Data 007 LD LxT_Data 007 LD LxT_Data 008 LD LxT_Data 009 FIGURE 10 9 Selection of File to be Overwritten LxT Manual Data Explorer 10 7 Refresh List Load Settings 10 8 Highlight Yes and press the Enter key to display the Overwrite Confirmation menu shown in FIGURE 10 10 LD LxT_Data 001 Eat Overwrite File FIGURE 10 10 Overwrite Confirmation Select the desired response and press the Enter key If you select Yes then the old file will be over written with the selected file A response of No will return to the Rename message box The Refresh List menu item will refresh the file list on the Data Explorer Page Using the Load Settings Menu item a new measurement may be run with the exact same parameters as the selected measurement When the Enter key is pressed the parameters from the selected measurement are loaded so a new measurement may be made This is a convenient method to duplicate a previous measurement Data Explorer LxT Manual System Properties The System Property Pages are used to identify and or control functions of the LxT that are not related to sound measurement or calculations Control Panel System Properties LxT Manual
69. 14 4 E LxT_Data EES Overall SEIT On Run Time 0 00 11 4 FIGURE 5 18 Equivalent Page Section 13 Section 13 displays three equivalent levels calculated for the total measurement time Lcsey and Laseg are equivalent levels measured using Slow RMS averaging and using frequency weightings of C and A respectively The difference between them Lcseg Laseg S often used as an indicator of the amount of low frequency content in a sound It is also used as a parameter for the selection of hearing protectors since noise fields having a large amount of low frequency sound can require more effective hearing protectors than would otherwise be indicated by the measured L4 seq level alone Overall Page 5 21 Session Log Page H 2006 Apr 23 15 36 24 Keypress Measurement 2006 Apr 23 15 36 42 2006 Apr 23 16 05 02 I 2006 Apr 23 16 05 06 2006 Apr 23 16 05 07 2006 Apr 23 16 05 12 FIGURE 5 19 Session Log Page The Session Log is a record of data accumulation actions A time stamped record is made for every Run Pause Stop Voice Message or Marker action The source responsible for each action is also recorded which may be any of the following e Key press USB command Run timer compete e Low battery e Out of memory e Preamplifier disconnect The icons in the left column of the display indicate the action Run Pause Voice Recording etc The date and time of the action is displayed next to the icon 5 22 Sess
70. 16 Changing Setup Pages ccccceeceescessescecseceeecseceseeeeeeeseeeeeeseeneeaes 3 17 Baler EE 3 17 Data EE se 3 18 System Properties ENEE 3 19 aja EE 3 19 Calibrate ups cd 3 20 Voice Recorder 2 ecceceeceeecceesseesteeeeeees 3 20 ABDOU iea ee 3 20 Chapter 4 Basic Measurement Setup Measurement Properties Screen 4 2 Accessing the Measurement Properties Sereen ooooonnnocinonionconncnnnns 4 2 Settings In Use Message 4 2 SOUP PAGES EE 4 3 Ee 4 4 SLM Pagen taen an a I A eea i 4 5 Frequency Weighting iesse eeen e E Eaei 4 5 Timo Weighting nerpie rse ia 4 5 Int gration enee o e AT 4 6 Dosimeter 1 and 2 Pages 4 7 Predefined Setups ANEN 4 8 Parameters Individually Defined 050000002 4 10 Name Field ir 4 10 Parameter Fields oon eon inten Acco EE a 4 11 Exchange Ratio e ee 4 11 Threshold and Criterion non nro no ro nnnnnrnnrnnos 4 11 Auto Calcul teriiinina EE EE 4 11 in Ge EE 4 12 Octave Band Analyzer Page Optional 4 13 OBA R nge Setting oe EEN EES 4 13 OBA Bandwidth Seng 4 13 OBA Frequency Wegbtmg 4 14 OBA Max Spectrum Mode 4 15 OBA Time Averaging occ cecceceeseessescesseceseeseceeceseeeenseeeeeeseeneeenes 4 15 IR eet Be GE 4 16 Manual Stop Modistas 4 18 Timed Stop Mode 4 18 Stop When Stable Mode uu eceeceseseseeeeceeceeeeeeseeseeeceeceaeeeeeseeeneees 4 19 Tiiggers Page E 4 20 RMS Trigger Levels voii ENEE dee ines 4 21 Exiting Measure
71. 3 B amp K UA0033 EA EA expanded uncertainty of Corrections 95 confidence add numbers in this column to levels read on the LxT to correct to the 0 Free Field level at a specific frequency EA Electrostatic Actuator WS Wind Screen e Linear Operating Range A weighted sound levels for the LxT2 at the upper and lower limits of the linear operating ranges 31 5 Hz 1 kHz 4 kHz 8 kHz 12 5 kHz 77 dB to 99 6 dB 34 dB to 139 dB 33 dB to 138 dB 36 dB to 137 9 dB 38 dB to 134 7 dB f Linear Measurements Starting Level The starting point for measuring the level linear errors on the reference range is 114 dB g Electrical Insert Signals The electrical design of the input device to insert electrical signals into the preamplifier is a series t 5 capacitor The Larson Davis ADP00S is used for this purpose The ADP005 can be used for noise floor measurements by attaching the included short on the front of the ADP005 18pF 3 LxT2 LxT Manual h Inherent Noise Inherent Noise of the LxT2 Weighting Total Noise Electrical Noise A 27 26 C 27 25 Fit 32 30 combination of the electronic noise and the thermal noise of the microphone at 20 C measured in a sealed cavity and vibration isolated electronic noise of the instrument with an ADP005 in place i Highest Sound Pressure Level The highest sound pressure lev
72. 5 LINKS tee 1 6 Click a Link to Display a Page ccceescesseeseescesseeeceeecseceseeeeneenseees 1 6 Return to Previous View 1 6 Cross References EEN 1 6 Click Cross References smc nat 1 6 Return To Previous VieW cccecccsseescessesseceeesecaeceseeseeneeeeceseeteenseees 1 6 Feat reS eebe 1 7 Hardware Features AA 1 7 Basic Measurements oocccocococcccnccnnnnnccnnnnnnnnnion 1 8 Basic Operation WE 1 8 Available OptiONS ooooooccccccoocccccncncnononcccnnnnnnnos 1 9 Standard Accessories ooooooccccccnonnccccncnnnnnannnonnns 1 9 Microphone and Preampltfer 1 9 OCR Foie E eth ees 1 10 Optional Accessories cooooooccccccccccoocccnnccnnnnnos 1 10 Microphones a A Mee ek ee ED 1 10 Microphone Preamplifiers cccccceseceseesecesceseeesceeeeeeeeseeeseeaeeaes 1 11 Microphone and Preamplifier Confgeuratons seee 1 11 Equivalent Electrical Impedance Adaptor ooocccoocnconionionnnoninncinnonno 1 11 Cables ease Re ee 1 11 e EE 1 12 EXT COMPONCINS a ec ee 1 13 Chapter 2 First Use Unpacking and Inspection occccoocncc 2 1 Record Serial Numbers of LxT and Components ococccioninnconncncnnonss 2 2 Connecting the Microphone and Preamplifier2 3 Connecting the Preamplifier to the LxT 2 4 Disconnecting the Preamplifier from the LxT2 5 Inserting Alkaline Batteries 001n000nnaaaen 2 6 Hardware Power Switch 2 7 Using USB Po Wena da 2 8 Chapter3 Overview Display and Softkeys
73. 50 114 0d6 1kHz o 114 0dB 1kHz FIGURE 13 4 Calibrating The Calibrating message box appears The present sound level 114 0 dB the difference between the calibration level and the present sound level A and an indication of stability are displayed in this message box When the pointer in the stability indicator is vertical the sound level is stable The Cancel button is highlighted Pressing the key will abort the calibration Calibrate 13 7 You can simply verify the calibration by selecting No Also if no significant changes are seen you may choose to answer No also LD 0 00 05 1 ZS Calibrate Tool Calibrate GT S LxT Save Results Ne 2 LD CAL150 114 0dB 1kHz O LD CAL150 114 0dB 1kHz O LD CAL200 114 0dB 1kHz O LD CAL200 94 0dB 1kHz FIGURE 13 5 Save Calibration When the calibration is completed a message box appears Selecting Yes will save the results of the calibration and No will cancel the results of the calibration Highlight the desired button and press the key Calibrate LxT Manual History Using the Right and Left Softkeys scroll to the History Page 38 23 24 0 i Calibrate Tool TES History Ae History Date Close FIGURE 13 6 History Page The History Page lists the last ten calibrations For each entry the date time change in sensitivity and microphone sensitivity are displayed LxT Manual History 13 9 Certification A certification interval
74. 7 8 29 2 Zwt 33 6 22 9 34 0 Table A 15 Noise LxT1 PRMLxT1 with 377B02 A 28 Technical Specifications LxT Manual LxT1 PRMLxT1L with 377B02 LxT Manual 377B02 PRMLxT1L and LxT1 Noise LxT1 8 PRMLxT1L Frequency Noise dB SPL 10 3 9 2 8 2 7 2 6 1 5 1 4 4 3 4 2 6 1 4 0 1 377B02 Noise dB SPL 21 2 20 2 19 2 18 2 17 2 16 2 15 2 14 2 13 2 12 2 17 Nov 05 LxT1 PRMLxT1L and 377B02 Noise Table A 16 Noise LxT1 with PRMLxT1L and 377B02 Technical Specifications A 29 LxT2 PRMLxT2 with 7052 LxT2 amp PRMLxT2 7052S LxT2 PRMLxT2 and 7052S Frequency Noise Noise Noise Hz dB SPL dB SPL dB SPL 6 3 13 6 17 2 13 6 7 9 12 9 16 2 12 9 10 0 10 6 15 2 10 6 12 6 11 7 14 2 11 7 15 8 11 1 13 2 11 1 20 0 10 4 12 2 10 4 25 1 10 0 11 2 10 0 31 6 10 6 10 2 10 6 39 8 8 8 9 2 8 9 50 1 7 6 8 2 7 7 63 1 6 4 7 2 6 6 79 4 6 0 6 2 6 3 100 0 6 2 5 2 6 5 125 9 5 1 4 2 5 6 158 5 5 5 3 2 6 0 199 5 5 1 2 2 5 9 251 2 5 4 1 2 6 3 316 2 5 9 0 2 6 8 398 1 6 5 0 8 7 5 501 2 7 4 1 8 8 5 631 0 7 6 2 8 8 9 794 3 8 6 3 8 9 9 1000 0 9 4 4 8 10 7 1258 9 10 2 5 5 11 5 1584 9 11 3 6 4 lt 128 1995 3 12 1 7 0 13 3 2511 9 13 1 7 5 14 1 3162 3 14 0 8 0 15 0 3981 1 15 0 8 4 15 9 5011 9 16 1 8 8 16 8 6309 6 17 0 9 2 17 7 7943 3 18 0 9 5 18 5 10000 0 19 0 9 6 19 4 12589 3 19 9 9 4 20 3 15848 9 20 9 8 8 21 2 19952 6 21 8 8 5 22 0 Awt 26 4 27 2 Cwt 25 6 27 0 Zwt 30 0 31 5
75. 8 44 02 6 0 dB 2 0 dB FIGURE A 6 LxT with 377B02 Microphone 45 105 and 165 degrees Technical Specifications LxT Manual Directional Characteristics LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 Tested 11 23 05 12 25 57 by Alex T Note PRMLxT1 0155 and 377B02 100650 Reference Mic B amp K Model 4189 Serial Number 2440346 Tested 11 23 05 08 44 02 6 0 dB 2 0 dB 2 0 dB 6 0 dB 10 0 dB 14 0 dB 18 0 dB Mic 1000 00 Hz Mic 1995 26 Hz Mic 3981 07 Hz Mic 7943 28 Hz FIGURE A 7 LxT with 377B02 1000 00 Hz 1995 26 Hz 3981 07 and 7943 28 Hz LxT Manual Technical Specifications A 19 LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 57 by Ale d 377B02 100650 Mic 1258 93 Hz Mic 2511 89 Hz Mic 5011 87 Hz Mic 10000 00 Hz FIGURE A 8 LxT with 377B02 Microphone 1258 93 Hz 2511 89 Hz 5011 87 Hz and 10000 00 Hz A 20 Technical Specifications LxT Manual LD Model LxT1 Serial 0010 Normalized to 251 19Hz 0 11 23 05 12 25 57 by Alex T RMLxT1 0155 and 377B02 100650 rence Mic B amp K Model 4189 Serial Number 2440346 Tested 11 23 05 08 44 02 oe 6 0 dB Mic 1584 89 Hz Mic 3162 28 Hz Mic 6309 57 Hz Mic 12589 25 Hz FIGURE A 9 LxT with 377B02 Microphone 1584 89 Hz 3162 28 Hz 6309 57 Hz and 12589 25 Hz LxT Manual Technical Specif
76. 9 Unweighited Peak is a D 20 Weighted peak ii ae dE D 21 Sound Level Threshold Lt EE D 21 Sound Level Profile oo ce eececcseseceeseceeseeeceececsececeececnececneescneeeceeescneeseeeeeeeeenees 5 3 Sound Levels Mag seet ee Seok AH A ae we 5 9 tte A E A N E E N 5 9 POA as 5 9 Sound Power Level D 21 Sound Pressure Level see Sound D 19 Sound Sped ane ioen A A eek saa Deka ode bes i D 21 Speaker Output since lain nde te oho ida 11 12 Specifications ACDC Outputs dl rs ce ees ei ea A 5 Directional Characteristics i n A 25 IRTEQUENICY RESP EEEE E A TEEN S A 16 Frequency Weighting Cie de A KEAR is A 7 AAA ed EE e A 4 Main Characteristics meranie e E la EE A 3 NOIS EE A 27 Physical Characteristics A 6 Power S uppl tic dada A 5 Res A ES vets A 7 Sound Level Meter sevics AE A T E A 10 Stability Indicator lt ooo iaa 3 3 Startup Period ci tul 7 2 Stop 8 6 NS 3 4 LxT Manual a 11 Stop Store KeY ico cias daa ala 3 11 LONE E 3 5 Storing the Measurement ccc cccccceeseescesceseseseesecnecseesessecsecseneesseeseeeseeenaeas 7 14 Overwriting a Saved Elle ia 7 15 System Properaties Pages co ronon nono conc n nn nonrra rca nono 3 19 Devices dabas am lola co le ce men bas no deal o e O han 3 19 Displays is 3 19 Ne EE 3 19 Ereterenesgz ed ados 3 19 MO a e ia 3 19 System Properties coco ii 3 19 11 1 At e ees ee S 11 5 Backlight Mode its 3 7 11 7 ET Ee 11 7 Battery Type iia ii a ENEE 11 8 Control Parl
77. A reset can be initiated when the LxT is running paused or a normally quiet area stopped However it must be stopped for the reset operation to be performed Resetting When Running or Paused If it is running or paused when the D RESET key is pressed a Stop Required Menu will be displayed as shown in FIGURE 7 8 0 03 21 4 5 BA LxT_Dat Stop Required Cancel Laeq 1s 32 9 dB EZ Las 32 8 dB LZpeak 60 5 dB Started 2006 Apr 21 13 58 10 FIGURE 7 8 Stop Required Prompt The OK response will already be highlighted so simply press the ENTER key to continue Otherwise press the E key to highlight Cancel and then the ENTER key to cancel both the Stop and the Reset operations After selecting to Stop the measurement the Save File Menu shown in Figure 7 9 on page 14 will appear to provide a choice of saving the measured data prior to the 7 12 Performing the Measurement LxT Manual Resetting When Stopped Starting a New Measurement Stopping the Measurement Note that the LxT can be stopped when either running or paused LxT Manual reset or not as described in Storing the Measurement on page 7 14 If the LxT is stopped when the gt RESET key is pressed the Stop Required Menu will not appear but the Save File Menu will appear to provide a choice of saving the measured data prior to the reset or not The Ca key RUN PAUSE key must be pressed to start a new measurement
78. AA rnnr ennen 5 23 Adjust Graph Menu 5 24 RUN Control ui ir 6 1 Control PAGS EE 6 1 RUN Mode Mena tati dida isis 6 2 Manual Stop Mode EE 6 3 Timed Stop OT 6 4 Entering Time in Timed Stop Mode 6 4 Stop When Stable Mode iii 6 5 Continuous Rum Mode ii tv eles Geen 6 6 Auto Store Report Start Time 6 7 Single Block BEE 6 7 Selecting Months for Single Block Tmer 6 8 Daily Timer Mode EE 6 9 Daily Timer Three Timed Stop Mode 6 10 Making a Measurement see KENNEN EEE E 7 1 Gelee Be ict tee peed te i nee te Se adie 7 2 Data Display Screen Live Page EEN 7 3 EI O 7 4 Position of Windscre Miscelanea 7 6 Placement of WindscreeN ooococnnninniccoconociconnnicnnenennenennnn anna 7 7 Leq and Running SPL EE 7 9 Multiple Sound Level Parametere 7 10 Stop Required ProMPliu sido 7 12 Save En TEE 7 14 Saved Data TEE 7 15 Overwriting a Saved File ccccccccceeeceeseesseeseseedecececneeceeeeteneeeees 7 16 Overwrite Confirmation oooococconnnnonnicncionn cnn ncnocononnn ran rnnnera ternas 7 16 VOICE Recording EE 8 1 Control Rae tea ic rs ti tied e In er A 8 1 Voice RECO i 8 2 Recording A e 8 3 Save Recording Gen le EE 8 4 ele 8 5 Time e TEE e Vicios 9 1 Time History Setup Men 9 3 Time History Setup Menu Enabled 9 4 Time History Period TEE 9 5 Time History Options WiNdOW ooocccccccccccccccccininnnnnananannnn nono nnnnnnos 9 6 Time History Display First Point Keypress Beginning Measurement9 7 Mea
79. B dB Hz dB dB dB 88 46 0 10 00 inf 1090 18 0 00 0 10 0 30 0 40 87 18 10 00 inf 1188 50 0 00 0 10 0 30 0 60 81 81 10 00 inf 1295 69 D 10 0 30 1 30 67 18 10 50 inf 1412 54 a3 10 2 00 5 00 LL 10 00 5 00 1995 26 91 10 17 50 inf 0 21 10 30 1 30 3981 07 91 10 42 00 inf 0 00 10 30 0 60 7943 28 90 lt 10 61 00 inf 0 00 10 30 0 40 15848 93 91 212 70 00 inf 0 00 10 30 0 30 Table A 13 Passband of 1kHz 1 1 Octave Filter Technical Specifications LxT Manual CR Sound Level Meter Model LxT Serial Number 0000033 Certificate of 1000 0 Hz Third Octave Filter Shape Larson Davis This Class 1 Sound Level Meter including attached PRMLXT1 preamplifier and ADP005 18pF input adapter was calibrated with a reference 1kHz sine wave The instrument s 1000 0 Hz filter response was then electrically tested using a 137 00 dBSPL sinewave at selected frequencies as specified in IEC 61260 am1 2001 09 10 00 0 00 10 00 20 00 30 00 40 00 50 00 60 00 70 00 80 00 90 00 100 00 1000 Frequency Hz Measured Uncert Limits Measured Uncert Limits dB dB dB dB dB dB 90 61 0 10 70 00 inf de 0 00 0 10 0 30 0 40 82 27 10 61 00 inf x 0 00 10 0 30 0 60 68 01 10 42 00 inf 0 14 10 0 30 1 30 75 25 10 50 inf 2 56 10 2 00 5 00 2 50 10 00 5 00 s 93 15 10 17 50 inf 0 29 10 230 1 30 ES
80. CI keys to highlight the field of the desired marker Pressing the 6 key will set Markers LxT Manual Setting All Markers Off Close Marker Control Window Markers Display an Off marker to the On state and place a check mark in the check box Similarly pressing the key will set an On marker to the Off state and delete the check mark from the check box To set all markers to Off press the right softkey labeled None Press the left softkey labeled Close to close the marker control window and return the display to the standard Time History display When any type of marker has been active during a time history measurement this will be indicated by a solid horizontal line at the top of the screen as shown in Time History Display with Frequency Spectrum Data Logged on page 9 11 LO 0 01 31 6 i LxT_Data MEET Time History Marker Indications d EE EN y Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 LxT Manual eypress FIGURE 9 20 Marker Indication on Time History Display The LxT Utility software provided with the LxT will show the names of the markers along with the time history data when the data is exported See the LxT User Manual for details Markers 9 21 9 22 Markers LxT Manual CHAPTER Data Explorer Control Panel Data Explorer To activate the Data Explorer Page press the A TOOLS key Use the 7 Z lor keys
81. Community Noise Descriptors C 10 DIN RE C 10 EES C 10 Ui EE C 11 Appendix D Glossary D 1 1i xiv Allowed Exposure Time CT D 1 Average Sound Level avg ono D 2 Community Noise Equivalent Level CNEL Lden o o oocooc D 2 Criterion Duration Taiana D 3 Criterion Sound Exposure CSE cococconcciocononionconnonnon ono non nonnncanonanonos D 3 Criterion Sound Level ch D 3 Daily Personal Noise Exposure ERAN D 3 Day Night Average Sound Level DNL Ldni ceeeeeeeeeeeeeeees D 3 Decibel dB eet e eet ee e A D 4 Department of Defense Level LDOD oooooccnccinnionconcconccnonncanocanonos D 7 RE D 7 Detecta D 7 Eight Hour Time Weighted Average Sound Level L TWA 8 D 8 Energy Equivalent Sound Level eg D 8 Exchange Rate Q Exchange Rate Factor q Exposure Factor k D 8 Pariente D 8 Eres EE D 9 Le ENEE E E D 9 Frequency Band Pass Elter D 9 Frequency Filter Weigbted D 10 ToC WEE D 11 Level dB cos Seege S D 12 Measurement Duration CT D 12 Microphone Guidelines c ceeceecesseeseesceseececeseeecesceseeeeeeseeneeenes D 12 Near Field geet eege D 14 eler GE D 15 Noise Dose RE D 15 NGIS EXPOSUTE sac nian ca Ho E A E E EK D 16 OSHA Level LOSHA RS D 16 Preamplifier sess sees D 16 Projected Noise Dose D 16 Single Event Noise Exposure Level SENEL LAST D 16 Dekret D 16 Sound Exposure GE D 17 Sound Exposure Level SEL LEI D 17 Sound MEN D 18 Sound Pressure
82. Displays LxT Manual LxT Manual those displays and press the key to obtain the display shown in FIGURE 11 19 1 1 Octave 1 3 Octave Dose 1 Dose 2 SEL FIGURE 11 19 Display Set to Appear or Hide Pressing the Q key will toggle the state of the highlighted display between Appear checked and Hide unchecked Use the gt and C keys to highlight different displays and set them as desired When finished setting the display types for this Tab Page press the Ge key When all desired modifications have been made to the displays for all Tab Pages press the center softkey Close to return to the Control Panel Displays 11 17 11 18 Displays LxT Manual Lock Unlock the LxT To prevent unauthorized use or tampering with measurements and data the LxT has a lock feature When this is enabled the LxT is tamper proof to a level selected by the user There are 4 levels of security provided by this feature Control Panel Lock To activate the Lock Page press the A TOOLS key Use the TT E or O keys to highlight the Lock icon as shown in FIGURE 12 1 Control Panel Data Calibrate Explorer Kl el System Voice Properties Recorder FIGURE 12 1 Control Panel Press the key to open the Lock Page There is one Lock Page There are three items on this page the user may configure LxT Manual Lock Unlock the LxT 12 1 gt 0 00 00 0 0 Lock Mode Unlock Code Enter a 4 digit code to use wh
83. E cota ai tdci D 15 Number of Measurements ooooicococococcococononccococonononncononconononnononnononnononnon canon cnn 5 20 O Octave Band Analyzer Page no nono noo nonncnco non rcnnca nono 4 13 Bandwidth Setting iii A eG Rie A deer 4 13 Eontrol Pac ei ei ince E E OE ed acetil iia 4 16 Brequency Weighting A Dae lee ae 4 14 Max Spectrum Mode a cad 4 15 Ranige Setting Se eit eee he NAA Ee Ee Ee 4 13 OTM Keys ad hse Ne o ee 3 7 D CHER ew eege ee ast ay ea a is 3 6 Power Control Pare ae 3 7 Puan ON ER EE 3 6 Optional Accessories Equivalent Electrical Impedance Adaptor ccceeccesseesceccesseeecseeeseceeeneeteceseneeenseees 1 11 OPTIONS EE 1 9 OSHA E EE D 16 Output NA A A te eee 11 12 DE A a iaa 11 12 A OR RO ON 5 19 Overwriting a Saved File ocio Se eit dh 7 15 P e EE 3 2 Parameters Measured ecccessssssesesseseeseseceeseceeseceeseceesececnececneeecneceeneeseneeecneeeens 17 1 Exceedance Counters ie 17 5 Miscellaneous Farameterg iii NEEN 17 6 Sound EXPOSURE 17 4 Sound Level EE 17 1 Sound Level M eterics ua a 17 3 Statistical Metrics 0 ii 17 5 Pausa RUN lado 3 11 PAUSE ICON curo iii 3 4 Power Control Screen 3 12 Power Indicator c cocoininion didactica EEEE a E ESS 3 2 Power Save E 11 6 Power Supply LxT Manual a 9 PS A029 A 16 8 USB A ais 2 8 Power Switch Hardware 2 7 Preamplifier Det anio D 16 Preferences Page A EE 11 8 EE 11 11 Date Me 11 10 Decimal Symbols ous eege ita leales 11 1
84. E 5 10 EDEN oia A ere C 10 E B N EE C 10 Left and Right KEYS chenn js 3 11 Rn WEE 5 8 O Bec ees Pha ns Aidt Aaa vs N D 8 ewe D 12 Dept ot Detras A NA D 7 RR ee Ee EE 1 6 Display EE 1 6 Return to Previous View ccccccscssscessecsseceseecsececseceeecessecesseceseecsuecessceseecssesesaeceeeecss 1 6 Live Pa Aichi eee 5 2 Bue EE 4 12 En Percentiles occ aa ee GE A hc eet a 5 17 Load SGettings ccc esceseeseneseeseesecsecseesesecseeeceecssesseseesecseesensesaeaeeesseseeeseeeesaes 10 8 LOG esi Soe tte ee tn eet Se ee 3 19 Lock Modes Fully LOCK Gd oo e laa 12 3 Lock with Auto Store nono ncnnnc con nrnn nc nn coo nnnonnnonnncinss 12 3 Tock with Manual Store ata e 12 3 Llole kert tele eege rer oe ee or On err 12 3 LOGK UNIOCK 3 erer icon tha keds hid Sh RG ee ee aeons 12 1 Allow Cal when Locke 12 5 Calibration when Locked daa 12 14 ControlPamel ss ont ee e geed 12 1 Fully BOCK eds tices ic een Nas tis RAR aoe 12 6 TO CRM OES 32 ee ase Ed ee 12 1 12 3 Locked With AO tores 12 9 Locked with Manual Store 12 12 Unlock Code rsr eecht hock sos hbase seh ash gsi AE Octo hid nestles Eeer 12 4 O 16 1 BALSA ais 16 6 COMPONENTS Na 16 1 COMA Ee Ee EE 16 5 R ONE 16 2 External Power SUP iii A dido 16 7 a 6 LxT Manual Hard Sii AA AA os 16 4 o E 16 5 Ka i 16 3 Microphones 14 eed I eh itn dg elev dee E evn 16 2 Microphone Preamplifier 2 3 ccccsccceveccesbecusiodieslevedeeuecsddensdaavgcdessddicesaedenevacctcendoetest 16 2
85. ER S PRODUCT WAS BUILT Authority to Alter This Limited Warranty No agent representative distributor or authorized dealer of LD has any authority to alter the terms of this Limited Warranty in any way This Limited Warranty may be altered only in a writing signed by an authorized officer of LD LxT Manual Warranty Customer Satisfaction E 3 E 4 Warranty Customer Satisfaction LxT Manual A brut eege did 10 1 EE 14 2 Control Pariel a Zeene E EAEE TEE A EA E 14 1 Credits A A Oa 14 6 RI TEE 14 4 e E EE 14 3 lege ee dbs ce ses ia E dea duces eegene Eed 14 5 About Fangere lek ei eis ee kh Gee eee O 3 20 ADO a eener eos esst 3 20 Opt v3 so eh A RGIS Eed Ae RO eA 3 20 Standards jeeed EE 3 20 lag as 3 20 AC DC e TTT EE 11 12 Accessories tele 1 9 Microphone Preamplitels ci ccna aise cee ER 1 11 Microphone Preamplifier ccccccesecsecesceseceeceecesceseeseceseeseecsecsaecssesaeceeeeenseeeeeeeaes 1 9 Microphones casi ooh ee AS ee 1 10 A A ee eene eege 1 10 Eeer Ee ee Ee Se 1 10 Stati ard DEET 1 9 Auto Sleep ci A RSA A EE TEA BRE 11 5 Auto SOTO eee ae ai elk Aa ERA RRR IB dese 11 11 B Backlight II ONE 3 12 Mods ii al 3 7 MA Ei es 11 7 Basic Data Display e aaa 5 1 Batteries iii eege veh co es SEN coh ces eae ce A pecan dav ei 16 6 Alignment EE 2 6 EE 2 6 IMSerting ii ai 2 6 Intrinsic ae id dl tats 2 6 Battery ii a dais 5 7 Battery Door STE 2 6 Removal A Seis Si crescent eon Oe taco de atin Bi ie Soe the oa othe
86. Field Corrections Effect of Frequency Wind Screen expanded uncertainty of Corrections 2660 73 2818 38 2985 38 3162 28 3349 65 3548 13 3758 37 3981 07 4216 97 4466 84 4731 51 Continued on next page LxT Manual LxTl 5011 87 E 0 1 5308 84 0 1 5623 41 y 0 1 5956 62 i E 0 0 6309 57 i 0 1 6683 44 0 1 7079 46 0 0 7498 94 E i 0 1 7943 28 h 0 3 8413 95 S 0 4 8912 51 i 0 5 9440 61 A S 0 3 10000 00 0 2 10592 54 0 1 11220 18 S 0 4 11885 02 E y 0 7 12589 25 0 7 13335 21 e 0 8 14125 38 E 0 5 14962 36 i 0 8 15848 93 A i 1 0 16788 04 1 0 17782 79 A 1 0 18836 49 0 9 19952 62 1 3 tadd numbers in this column to levels read on the LxT1 to correct the level at a specific frequency Section 9 3 a Reference Sound Pressure Level The reference sound pressure level is 114 dB re 20 Pa b Reference Level Range The reference level range is normal c Microphone Reference Point The microphone reference point is the center of the diaphragm of the 377B02 microphone d Periodic Testing Table 2 lists values of Larson Davis LxT1 with PRMLxT1 and 377B02 Microphone adjustment data of A weighted levels used for periodic measurements B 10 LxT1 LxT Manual Table 2 Larson Davis LxT1 with PRMLxT1 and 377B02 Microphone adjustment data of A weighted levels used for periodic testing at a specific frequency EA Electros
87. Hz 2511 89 Hz 5011 87 Hz and 1000000 EE A 20 LxT with 377B02 Microphone 1584 89 Hz 3162 28 Hz 6309 57 Hz and ZOO ZO EE A 21 LxT with 7052 Microphone 0 60 and 120 degree ooooooooconccnnccno o A 22 LxT with 7052 Microphone 15 75 and 135 degrees snnennna0000 A 23 LxT with 7052 Microphone 30 90 and 150 degrees oooccccooccccno o A 23 LxT with 7052 Microphone 45 105 and 165 degrees oooooooo A 24 LxT with 7052 Microphone 1000 00 Hz 1995 26 Hz 3981 07 and 7943 28 EE A 25 LxT with 7052 Microphone 1258 93 Hz 2511 89 Hz 5011 87 Hz and MOO OOO OZ A A A o Ee A 26 LxT with 7052 Microphone 1584 89 Hz 3162 28 Hz 6309 57 Hz and A EE A 27 Certificate of Conformance DRM vi A 36 Certificate of Conformance DRMvIIL A 40 iii vi Certificate of Conformance PRMLXT2 c cccccceeceseeeeeeeeeeeeeees A 45 Certificate of Conformance DRMvTZ A 50 KEE C 3 Sound Exposure Level and Sound Exposure coooooncccccccccccccincnccnnnno C 5 DOSEvand Projected DOSE sidra caco it C 8 111 V11 iii viii List of Tables Introduction 1 1 Microphone and Preamplifier cccccceeeeeeeeeeeeeeeeeeeeeeeeees 1 9 First Use 2 1 Overview 3 1 Chapters Describing Functions From the Control Panel 3 10 Basic Measurement Setup 4 1 Predefined Noise Dosimeter Setups ooooocccccccccccccccccccnnnncnnnnnos 4 8 Basic Data Display 5 1 Run Control 6 1 Making a Measurement 7 1 Voice Recording
88. IGURE A 17 Certificate of Conformance PRMLxT1 A 36 Technical Specifications LxT Manual Model PRMLxT1L The Larson Davis PRMLxTIL is an electret microphone preamplifier for use with Larson Davis LxT Sound Level Meters It requires very little supply current and will drive 200 feet of cable The pream plifier operates over wide temperature and humidity ranges It is for use with 50 mV Pa sensitivity microphones up to 118 dBSPL Specifications Frequency response with respect to the response at 1 kHz with 1 1 Volts rms input and 18 pF equivalent microphone 4 Hz to 10 Hz 0 1 0 5 dB 10 Hz to 40 kHz 0 1 0 18 dB Lower 3 dB limit lt 1 5 Hz Attenuation 1 2 dB typical Input Impedance 10 G Ohm 3 pF Output Impedance 50 Ohm Maximum Output 2 8 Vpp 121 dB peak for microphones with 50 mV Pa sensitivity Maximum Output Current 10 mA peak Distortion Harmonics lt 67 dBc with 0 7 Volt rms output at 1 kHz Output Slew Rate 2 V uS typical LxT Manual Technical Specifications Electronic Noise with 18pF equivalent microphone 1 8 uV typical A weighted 2 5 uV max 3 2 uV typical Flat 20 Hz to 20 kHz 5 uV max Power Supply Voltage 6 to 15 Volts DC Output Level 1 2 power supply voltage Power Supply Current 1 3 mA typical Temperature Sensitivity lt 0 05 dB from 10 to 50 C 14 to 122 F operating range to 60 C 140 F Humidity Sensitivity lt 0 05 dB
89. Introduction Welcome to the Larson Davis SoundTrack LxT This versatile instrument with graphic display performs the functions of several instruments It puts the combined features of a precision sound level meter and a real time frequency analyzer in the palm of your hand About This Manual This manual has 18 chapters and 5 appendices covering the following topics Chapters LxT Manual Chapter 1 Introduction Orients the user to the contents of this user manual and the LxT features functions and measurement capabilities Chapter 2 First Use Describes the process of unpacking the LxT and preparing for first use Chapter 3 Overview A brief discussion of the displayed views the keypad and navigation through the various functions of the LxT Chapter 4 Basic Measurement Setup A detailed description of setting up the LxT for the measurement of basic sound level parameters Chapter 5 Basic Data Display A detailed look at the various metrics and information presented on these screens during and following a basic sound level measurement Introduction 1 1 1 2 Chapter 6 Run Control The LxT provides a number of run modes to control the time duration of a measurement These include Manual Stop Timed Stop Stop when Stable Continuous Single Block Time and Daily Timer modes Chapter 7 Making a Measurement Describes the important steps in making an accurate sound level measurement Chapter 8
90. Larson Davis TRACK Operation Manual Larson Davis 1681 West 820 North Provo UT 84601 1341 Phone 888 258 3222 FAX 716 926 8243 www LarsonDavis com 1770 01 Rev E Copyright Copyright 2006 by Larson Davis Inc This manual is copyrighted with all rights reserved The manual may not be copied in whole or in part for any use without prior written consent of Larson Davis Inc Trademark SoundTrack LxT and Blaze are registered trademarks of Larson Davis Inc Disclaimer The following paragraph does not apply in any state or country where such statements are not agreeable with local law Even though Larson Davis Inc has reviewed its documentation Larson Davis Inc makes no warranty or representation either expressed or implied with respect to this instrument and documentation its quality performance merchantability or fitness for a particular purpose This documentation is subject to change without notice and should not be construed as a commitment or representation by Larson Davis Inc This publication may contain inaccuracies or typographical errors Larson Davis Inc will periodically update the material for inclusion in new editions Changes and improvements to the information described in this manual may be made at any time Equal Opportunity Employer Larson Davis is an equal opportunity employer and does not discriminate on the basis of race color religion gender national origin di
91. Level SPL Lt D 19 Sound Power WJ r cht gat A ai ee ieee eed D 21 li xv Sound Power Level PWL Lei D 21 Sound Speed Chunta aaa D 21 Spectrum Frequency Spectrum oooooonocioconocionconconnonnncnncnnonnncnnonnnnnos D 21 Threshold Sound Level On D 21 Time Weighted Average Sound Level TWA LTWA TC D 22 Time Weighting ee iz D 22 MID rations a do og ee are td D 22 Wavelength liinda D 22 W aventim ber CK iris D 23 Appendix E Warranty Customer Satisfaction E 1 1i xvi List of Figures ae ee LTE 1 1 BOOKMAIrKS as 1 4 Bookmarks Expanded AAA 1 5 Oats Bo ieee iS 1 13 LXT Bottom WEE 1 14 IESSE UE 2 1 Microphone EEN 2 2 Microphone Preampllifier ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeseeeeeees 2 3 Preamplifier Connected Anke 2 4 Push Button to Release Preampitter 2 5 Disconnect The Preamplificador es 2 5 Battery Diere ES 2 6 Insert EE 2 7 e 3 1 Data Display Sres 3 1 Power Control VICW cccicolcio at dicen o ia een E 3 7 Stop Required Pro Plastica date See d r geet 3 8 Veirel EE 3 10 Main View Block Diaoram 3 12 Data Display Green 2eseeeEEEEEEEEEEEEEEEREEEEEEEEEEESEEEEENEEEEEREEEEEEE EEN 3 15 Measurement Properties Gcreen EEN 3 17 TOS SEE EE 3 17 Highlighting a Tools Icon BEE 3 18 System Property PAGES cti calidad ea ara adas 3 19 Softkey Selection of About Pages AA 3 20 Basic Measurement Setup SEENEN KENE Ek 4 1 Settings In Use By LxT Utility Message 4 2 Tabbed Setup Pages
92. Locked With Auto Store If the Locked w Auto Store mode has been selected upon accepting the changes on the Lock Page the view would look as shown in FIGURE 12 10 Locked with Auto Store or Manual Store 0 02 35 6 o gt Date 2006 Mar 06 16 35 59 Laseg 64 8 dB LAS 45 1 dB LASmax 86 7 dB Started 2006 Mar 06 16 33 09 FIGURE 12 10 Locked with Auto Store or Manual Store In this mode measurements may be started by pressing the ay RUN PAUSE key A measurement may not be LxT Manual Locked With Auto Store 12 9 12 10 Paused or Stopped Pressing the CR STOP STORE key will initiate storing the data file a gt 0 02 57 5 i Date 2006 Mar 06 16 36 46 Measurement OK Yes No LASeq 64 1 dBE amp LAS 46 0 dB LASmax 86 7 dB Started 2006 Mar 06 16 33 09 FIGURE 12 11 Auto Store Stop Use the O O and keys to select the desired response If Yes is selected the data file will be saved The unit is still locked and a new measurement may be started by pressing the Ei RUN PAUSE key If No is selected the data is reset and a new measurement may be made Locked With Auto Store LxT Manual Unlock To unlock the LxT press the A TOOLS key the key or the Right or Left Softkey Enter your 4 digit code then press the key 5H 0 02 57 5 i Date 2006 Mar 06 16 37 55 Enter 4 digit code Laseg 64 1 dBEJ LAS 45 7 dB LASmax 87 8 dB Started 2006 Mar 06 16 33 09 FIGURE 12 12 Auto Stor
93. LxT Manual Difference between sound and noise Sound is the physical phenomenon associated with acoustic small pressure waves Use of the word sound provides a neutral description of some acoustic event Generally noise is defined as unwanted sound It can also be defined as sound that causes adverse effects on people such as hearing loss or annoyance It can also be defined as the sound made by other people In every case noise involves the judgment of someone and puts noise in the realm of psychology not physics Rules 1 Use word sound to describe measurements to remove the emotional overtones associated with the word noise Some sound metrics use noise in their name and it is proper to use the name as it is It is the total sound energy of the actual sound during a specific time period It is expressed in Pascals squared seconds T SE Adr T where pa is the sound pressure and T T is the Measurement Duration specific time period When applied to hearing damage potential the equation is changed to T SE Jiha T where k is the Exposure Factor See Exchange Rate Standard ANSI S1 25 The total sound energy in a specific time period The equation for it is Glossary D 17 Sound Pressure D 18 T Poa SEL 10Log 2 Pol The sound pressure is squared and integrated over a specific period of time T gt T this is called the sound exposure and has the units Pascal squared sec
94. Menu Using the J and CH keys select the desired function Press the key to execute the function selected To leave this menu without taking any action press the Close Softkey Data Explorer 10 3 View The View function opens a data view of the selected data WR 0 00 05 1 e LxT_Data 018 Overall EXE ia file Laseg 75 6 dBE Las 75 6 dB Started 2006 Apr 24 13 24 25 FIGURE 10 4 Data View Page The Data View screen is similar to the Data Display screen See Overall Page on page 5 8 The file name of the data file being displayed is found in the title bar near the top of the screen For information on the Session Log Page see Session Log Page on page 5 22 Pressing the Center Softkey labeled Close returns the screen to the Data Explorer view 10 4 Data Explorer LxT Manual Delete Delete All LxT Manual This deletes the selected stored data file When the Delete menu item is highlighted and the as Enter key is pressed a message box appears asking you to confirm the request to delete the file Delete File FIGURE 10 5 Delete File Highlight the appropriate response using the O or O keys and the nt Enter key This deletes all of the stored data files When the Delete All menu item is highlighted and the nes Enter key is pressed a message box appears asking you to confirm the request to delete all files 0 00 01 6 Data Explorer LD LxT_Data 001 Delete All File
95. OFast Impl Peak Weighting OA oc KE Integration Method O Linear Exponential 4 Close b FIGURE 4 4 SLM Page Selections of Frequency Weighting Detector Peak Weighting and Integration Method are made one at a time using the and CI keys to move the highlight to the desired section prior to making the selection Use the and O keys to highlight S appropriate item for the selected parameters Press the nes key to make the selection A C and Z frequency weightings are provided for the RMS and peak detectors These are selected separately Available time weightings for the RMS detector are Slow Fast and Impulse Setup Pages 4 5 Integration Note that the LxT can be set to run for a preset integration time as described in Timed Stop Mode on page 6 4 Two Integration methods are available Linear and Exponential Exponential Integration Exponential integration would typically be selected to provide compatibility with older analog instruments in which all measurements involve exponential time weighting of signals Exponential detectors have a tendency to hide small events in the long decay of a loud impulsive event Linear Integration Linear integration integrates only energy that occurs during a given time period and therefore does not exhibit the decay slope of a Fast Slow or Impulse exponential detector The value of the integrated level is displayed immediately following the end of
96. OR SUPPLIERS BE LIABLE TO THE BUYER FOR ANY LOST PROFITS DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT IN TORT OR ANY OTHER LEGAL THEORY SUCH DAMAGES FOR WHICH LD SHALL NOT BE RESPONSIBLE INCLUDE BUT ARE NOT LIMITED TO LOST TIME AND CONVENIENCE LOSS OF USE OF THE PRODUCT THE COST OF A PRODUCT RENTAL COSTS OF GASOLINE TELEPHONE TRAVEL OR LODGING THE LOSS OF PERSONAL OR COMMERCIAL PROPERTY AND THE LOSS OF REVENUE Some states do not permit the limitation or disclaimer of incidental or consequential damages Therefore the above disclaimer of incidental or consequential damages may not apply to certain purchasers F NO LIABILITY IN EXCESS OF PURCHASE PRICE IN NO EVENT SHALL LD S OBLIGATIONS UNDER THIS LIMITED WARRANTY EXCEED THE PURCHASE PRICE OF THE PRODUCT PLUS ANY SHIPPING CHARGES THAT LD MAY BE OBLIGATED TO PAY PURSUANT TO PARAGRAPH C ABOVE G NO_EXTENSION OF STATUTE OF LIMITATIONS ANY REPAIRS PERFORMED UNDER THIS LIMITED WARRANTY SHALL NOT IN ANY WAY EXTEND THE STATUTES OF LIMITATIONS FOR CLAIMS UNDER THIS LIMITED WARRANTY H WAIVER OF OTHER WARRANTIES THE EXPRESS WARRANTIES SET FORTH IN THIS LIMITED WARRANTY ARE IN LIEU OF AND EXCLUDE ANY AND ALL OTHER WARRANTIES EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Some states do not permit the disclaimer of implied warranties Therefore the above
97. Octave v OBA Frequency Weighting OBA Max Spectrum Mode Close FIGURE 4 10 OBA Page Use the Left and Right Softkeys to select Normal or Low range and press the ene key to accept the selection In the Low range the gain is increased by 30 dB to provide a stronger electrical signal for the measurement of low level sounds When the LxT OB1 firmware is enabled the only choice will be to set the 1 1 octave On or Off When the LxT OB3 firmware is enabled the user can select to perform 1 1 Octave analysis 1 3 Octave analysis both 1 1 and 1 3 Octave analysis simultaneously or None Dosimeter 1 and 2 Pages 4 13 Use the arrow key to highlight the OBA Octave data field and press the key to open the OBA Bandwidth Menu OBA Bandwidth 1 1 1 3 Octave FF 1 1 Octave 1 3 Octave 1 1 1 3 Octave FIGURE 4 11 OBA Bandwidth Menu Turning off the frequency analysis Left click on the desired frequency bandwidth to make a will reduce the battery drain selection Select Off to have no real time analysis module active OBA Frequency Weighting The user can select to frequency weight the 1 1 and or 1 3 Octave frequency analysis modules using A C or Z weighting Use the gt arrow key to highlight the OBA Frequency Weighting data field and press the key to open the OBA Frequency Weighting Menu OBA Frequency Weighting FIGURE 4 12 OBA Frequency Weighting Menu Use the CH and C keys to move the highlight
98. Parameters oocccccccccnccnccnnccnconnnnnnns 9 1 Sound Pressure Level Values oooooononccccnnncccnonocononnconnnncnornnnronanaconnnos 9 1 Specialized Acoustic Parameter 9 2 1 1 and 1 3 Octave Spectra cceccecceecesseessessecseeseeseceeeteceeeesesereneeeaes 9 2 Non Acoustical Parameters occoncconcccncnnncncnns 9 3 From Ex Tia idad 9 3 Time History Setup aannannnnannneannenennnnnnnnne 9 3 Set Time History Period A 9 5 Select Time History Parameters 9 6 Exiting Time History Options 0 ccceececceeseescesseeseceeceseeeeeeteeteeeeeees 9 6 Time History Display ooocccccoooncccccncccnnnno 9 7 Single Value Parameters oooocccccoooccccccccccnncccnnnos 9 7 Data Display at Cursor Position ccccccsceeceeseceseeeeceteeeeceeeeteesteneeaes 9 8 Displaying Other Time History Parameters 2 0 0 0 ceesseseceseteceeeeeeees 9 9 ii vii Frequency Spectra Display 9 10 1 1 or 1 3 Octave Gpechra 9 11 Moving the Frequency Cursor ooooooconcccocnonoccnncnnnnnnononcnnnonnnncnnonacnnanno 9 13 Changing the Time Interval Value 0 0 cc cececeseeeeeeeeeeeeereeeseenees 9 14 Returning to Time History Display cccceccesseesceeseeeeeneeeseeneeenes 9 14 1 1 and 1 3 Octave Spectra cceeeeee 9 15 Mark Seeon n EE EES 9 18 Markers Setup REENEN 9 18 Naming a Marker iia 9 19 Using MarkePrs ccccccssesseeeeeeseeeeeeeeeeeeenees 9 20 Setting Markers OOff oococoni
99. Press the STOP STORE key to suspend the overall measurement Pressing the Ez key RUN PAUSE key afterwards will continue the overall measurement which had been stopped Performing the Measurement 7 13 Storing the Measurement Note a measurement can only be To store the measurement press the CR STOP STORE stored when the measurement has key one more time The Save File menu will then be been stopped displayed as shown in FIGURE 7 9 Save File Menu gt 0 00 02 6 Save File LxT_Data D11 LAeg 1s 52 1 dBEL Las 51 7 dB LZpeak 80 7 dB Started 2006 Jun 14 16 06 46 FIGURE 7 9 Save File Menu The data will be stored under the file name defined in the section General Page on page 4 4 TEST 3 in FIGURE 7 9 along with a file number The file number automatically begins at 000 for the first measurement stored and will index so that whenever a measurement is stored the file number assigned will be the next in sequence following the measurement previously stored After a file has been successfully To continue with the save operation use the right arrow key stored the LxT will automatically to highlight Yes and press the key reset when the i RUN PAUSE key is pressed to begin another To abort the save operation use the right arrow key to measurement highlight No and press the as key 7 14 Storing the Measurement LxT Manual Overwriting a Saved File LxT Manual If you wish to use this da
100. Pressure Level can be converted to sound pressure as follows If the sound pressure is 1 Pascal then the sound pressure level is i Die 2log 50000 20 4 699 94 0dB 20 10 Calibrators often use a level of 94 dB so they generate a sound pressure of Pascal If the sound pressure level 76 3 dB then the sound pressure is Pa 20610 e10 20 109 20 10 20 0 0065 0 13 Energy Average Leg The value of a steady sound measured over a fixed time period that has the same sound energy as the actual time varying sound over the same period This descriptor is widely used It is a fixed average See Sound Pressure Impulse The value of an impulsive sound The reading will depend on the time weighting applied Unweighted Peak The peak value of a sound with a meter that has flat frequency weighting and a peak detector Glossary LxT Manual Sound Power W Sound Power Level PWL Ly Sound Speed c Spectrum Frequency Spectrum Threshold Sound Level Lt LxT Manual Weighted Peak The peak value of a sound with a meter that has a frequency weighting other than flat and a peak detector The sound power emitted by a sound source It is measured in Watts The logarithmic form of sound power It is also expressed by attachment of the word decibel to the number The logarithm is taken of the ratio of the actual sound power to a reference sound power which is 1 pico watt Sound power level
101. Range C 39 to 140 dB 29 to 118 dB 37 to 139 dB 35 to 126 dB 10 to 117 dBuV Z 44to 140 dB 34 to 118 dB 42 to 139 dB 42 to 126 dB 16 to 117 dBuV Noise Floor A 29 dB 17 dB 27 dB 21dB 2 8 dBuV C 29 dB 19 dB 27 dB 25dB 1 3 dBuV Z 34 dB 24 dB 32 dB 32dB 5 6 dBuV Linearity A gt 104 dB gt 102 dB gt 103 dB gt 102 dB gt 106 dBuV Range 36 to 140 dB l6to 118 dB 36to 139 dB 24 to 126 dB 11 to 117 dBuV C gt 105 dB gt 100 dB gt 104 dB gt 100 dB gt 107 dBuV 35 to 140 dB 18 to 118 dB 35 to 139 dB 26 to 126 dB 10 to 117 dBuV Z gt 103 dB gt 93 dB gt 100 dB gt 93 dB gt 103 dBuV 37 to 140 dB 25 to 118 dB 39 to 139 dB 33 to 126 dB 14 to 117 dBuV SPL Max 140 dB 118 dB 139 dB 126 dB 117 dBuV Level Peak Max 143 dB 121 dB 142 dB 129 dB 120 dBuV Level Peak Range A 71 dB 71 dB 71 dB 71 dB 71 dBuV C 71 dB 70 dB 71 dB 71 dB 70 dBuV Z 66 dB 66 dB 66 dB 66 dB 66 dBuV Microphone and electrical self noise included Electrical Measurements Table A 11 LxT Performance Specifications LxT Manual Technical Specifications A 9 A 10 Sound Level Meter Specifications RMS Time Slow Fast or weighting Impulse Frequency A CorZ Weightings See Table A 10 on page A 7 Peak detector A CorZ Frequency weighting Reference range Normal range Exchange rates 3 4 5 or 6 dB Sample rate 51 200 Hz Peak rise time 28 uS Table A 12 Sound Level Meter Technical S
102. X is RMS frequency weighting Y is peak frequency weighting and V is time weighting The Count is the number of times each parameter has exceed the preset level The duration is the total accumulated duration of all exceedances for a specific parameter Miscellaneous Parameters S E A SEA is a time integration of peak levels that exceed 120 dB 17 6 Miscellaneous Parameters LxT Manual CHAPTER Memory Utilization This chapter presents formulas to calculate the amount of memory used by the parameters which can be stored to internal memory Overall Data Each overall data block stored when performing a Save File operation will utilize 27 kB of memory Session Log The amount of memory utilized in bytes when storing a session log is calculated as follows 40 12 Number of records where Number of records includes all Run Pause Stop Voice Message and Marker events LxT Manual Memory Utilization 18 1 Time History The amount of memory utilized in bytes when storing a time history block is calculated as follows 40 16 Number of parameters enabled Number of records where Number of Records Number of Samples Number of Run Pause and Stop events Voice Messages The amount of memory utilized in bytes when storing each voice message is calculated as follows 24 20480 Record Length where Record Length is in seconds 18 2 Time History LxT Manual APPENDIX Technical Sp
103. a dB re 1V Paj Low dB High dB PRMLxT1 50 22 8 3 6 48 9 51 9 45 9 PRMLxTIL 50 13 43 2 27 3 30 3 24 3 PRMLxT2 22 6 14 6 4 2 47 5 50 5 44 5 PRMLxT2L 22 6 1 3 19 5 34 2 37 2 31 2 Table A 19 LxT Preamplifiers The following sections present the specifications for the four different microphone preamplifiers which can be used with the LxT Model PRMLxT1 The Larson Davis PRMLXxT1 is an electret microphone preamplifier for use with a Larson Davis LxT Sound Level Meter It requires very little supply current and will drive 200 feet of cable The preamplifier operates over wide temperature and humidity ranges It has a built in attenuation of 23 dB for use with 50 mV Pa sensitivity microphones up to 140 dBSPL Specifications Frequency response with respect to the response at 1 kHz with 13 Volts rms input and 18 pF equivalent microphone 4 Hz to 10 Hz 0 1 0 2 dB 12 6 Hz to 40 kHz 0 1 0 1 dB Lower 3 dB limit lt 1 Hz A 32 Technical Specifications LxT Manual Attenuation 22 8 dB typical Input Impedance 10 G Ohm 5 3 pF Output Impedance 50 Ohm Maximum Output 2 8 Vpp 143 dB peak for microphones with 50 mV Pa sensitivity Maximum Output Current 10 mA peak Distortion Harmonics lt 60 dBC with 0 7 Volt rms output at 1 kHz Output Slew Rate 2 V uS typical Electronic Noise with 18pF equivalent microphone 1 1 pV typical A weighted 1 4 uV max 1 6 uV typical Flat 20 Hz to
104. a ora 11 1 Device Pr ias 11 2 Display Contrast a a rea 3 7 11 7 Display Customization iio 11 14 Ne o nave cta 11 5 Power Save KEE 11 6 A 11 8 Ee EE 11 3 System Hee tics cies resets debris tees ence seers ee eae 15 1 Control EE 15 1 Bile ti boa 15 2 Format Internal Memory eiii aiii 15 3 Format Internal Memory and Restore Deifaults 15 3 T A ees 3 2 A do 7 4 fuere ee ee AA ee Ee EE 7 4 ESOO O ac eves AR ks 7 4 Technical Specifications o ooonooniononnconnnoncononanonnnnnnonnnonnonncon corno ronca conncnnons A 1 Declaration of Condor E eases che tenes E A 1 A 2 Se A 1 Standards Mr de Ae es alo o a Ta Sey A 1 Technical Support 1 11 TIMO iii A ENEE 5 7 Allowed Exposure time Ti ccscesccssesssesseeseeeseeeeeeeeeseeeeecaecsaecaeesaecseesaeeeesseeaeeereees D 1 WA A D 22 Time History oo ccc ccecesessessesecnecsseseesessecseeecsaesseeesessecsecsessecsecaseecsaesaseseeessseeeaees 9 1 LKE O 9 7 a 12 LxT Manual FREQUENCY SPECIAL AA aaa esate 9 10 Marks E EAE uk oss ens pes comes ay E 9 18 Parameters Lor ii aci 9 1 ANE EE 9 3 Time History Parameters mind deed 9 6 Time History Period mi seas pieestaseiGaSheceardes ttt a de wie 9 5 Time Setting ico ee Bes es eae ee 11 3 Time Weighting WEE 4 5 LST EE 3 12 THIQGers te E 4 20 RMS Trigger Levels ii EENS 4 21 TIPOS EE 1 12 TWA TO EE D 22 U Unpacking and Inspecton ccc e EE 2 1 Up and Down Keys 3 11 WSB Rower eet eet BAR e ii 2 8 5 7
105. al Stabilization Time ceceeeeseesecesceeeeesceeeeeeeeseeeseeaeeenes B 12 m Field Strength gt 10 vim B 13 n Radio Frequency Pmission non nonnnnnos B 13 0 AC Power and Radio Frequency Susceptibility B 13 11 X111 ae B 13 Section 9 2 EE B 13 a Calibrator nenne e Bain ee A B 13 b Calibrator Frequency ccccescceseeseeseeesececessecseceaeeeceeeeeenseeerenes B 13 c Calibration Procedure ii ts B 13 d Frequency Respond B 14 Section I J e E EE EEEREN B 15 a Reference Sound Pressure Level B 15 b Reference Level Range B 15 c Microphone Reference Pomt B 15 d Periodic Testi ease ie ete B 15 e Linear Operating Range B 16 f Linear Measurements Starting Level B 16 g Electrical Insert Sugenals B 16 h Inherent Noise cnica iii B 17 1 Highest Sound Pressure Level ccscescceseesseeseeeeeeeeeseeeseeaeeenes B 17 j Battery Power Voltage Range B 17 K RE OR EE B 17 1 Typical Stabilization Time ceceeceseeeecesceeeeesceeeeeeeeseeeeeeneeenes B 17 mm Field Strength e HIN ies as B 18 n Radio Frequency Emisston B 18 o AC Power and Radio Frequency Susceptibility B 18 Appendix CG Integrated Level Calculations C 1 Basic Integrated Level Calculations C 1 Equivalent Continuous Sound Level C 1 Time Weighted Averages eens C 2 Dose and Projected Dose Calculations C 5 Sound Exposure Calculatons C 8
106. alibrating the LxT1 and 377B02 microphone on page 13 3 Using the 7 and O keys highlight each text box in the calibrate section of the page and enter the correct information about a calibrator Press the key to highlight the first character in the text box The 7 E O and O keys are_used to edit the information in the text box Press the key to complete entry When the calibration level calibration frequency and calibrator description have been entered highlight the Save button and press the key to save the information to the list of calibrators Calibrate 13 5 0 01 19 9 o Calibrate Tool Calibrate Calibrator Tade pohe Save Description CAL200 SN3970 114 CAL200 SN3970 114 QU Lee 0 FIGURE 13 3 New Calibrator If the desired calibrator is already in the list highlight the calibrator and press the key The radio button next to the selected calibrator will be filled in and the calibration information will appear above Calibrate LxT Manual Calibrating The LxT Refer to the calibrators operating instruction for more information LxT Manual After selecting a calibrator from the list above the LxT is ready for calibration Carefully insert the microphone into the microphone opening in the top of the calibrator Turn on the calibrator Highlight the Calibrate button on the LxT and press the Core key 114 0 dB El A 0 0 dB Cancel O LD CAL200 94 0dB 1kHz O LD CAL1
107. amplifier body DO NOT use excessive force When removing the microphone turn while gripping the microphone body not the grid cap to prevent damage to the microphone diaphragm LxT Manual Connecting the Microphone and Preamplifier 2 3 Connecting the Preamplifier to the LxT Note The connectors are keyed for The bottom end of the preamplifier has a 5 pin connector correct alignment that fits snugly into the top of the LxT Insert the preamplifier into the mating connector on the LxT Rotate the preamplifier until the keyways line up Press the assemblies together until a small click is heard The microphone preamplifier assembly is now securely attached to the LxT Caution Do not attempt to unscrew If the LxT is ON when the preamplifier is connected to the the collar ring at the top of the LxT Lt the Preamp Connected message box will appear for body several seconds Preamp Connected FIGURE 2 3 Preamplifier Connected Press the key to clear the message box 2 4 Connecting the Preamplifier to the LxT LxT Manual Disconnecting the Preamplifier from the LxT When transporting the LxT it is On the front surface of the LxT just below the preamplifier recommended that the preamplifier connector is a small button Press and hold this button while and microphone be detached and pulling the microphone preamplifier assembly out of the placed in a secure location in the LxT carrying case Preamplifier Release Butto
108. ange shown in Table A 10 Frequency Weightings Larson Davis on page A 7 inherent self generated noise and linearity problems can be ignored It is possible to correct the measured RMS sound pressure levels for the typical inherent noise levels see the noise floor specifications in Table A 11 LxT Performance Storing the Measurement LxT Manual Specifications on page A 9 as long as the difference between the measured sound level and the inherent noise level is greater than 3 dB This is done by subtracting the inherent sound level from the total sound level using the following formula Lmeas 10 9 Enh 10 Lcorr 10log 10 where Lcorr corrected sound level Lmeas measured sound level Linh inherent noise level LxT Manual Storing the Measurement 7 17 7 18 Storing the Measurement LxT Manual CHAPTER Voice Recording Control Page Voice Recording To activate the Voice Recorder Page press the A TOOLS key Use the 7 6 or keys to highlight the Voice Recorder icon as shown below ES 0 00 02 3 o FIGURE 8 1 Control Panel Press the key to open the Voice Recorder Page Press the Close Softkey to exit from this page By connecting a headset to the headset jack on the bottom of the LxT voice annotation may be recorded using the headset microphone Voice records may be played back through the headset speaker With no headset plugged in a record may be made o
109. ary D 3 Decibel dB D 4 LA 10Log p 0700 2200 2400 1 L 10 10 L 10 L 10 10 24 10 1 10 10 0000 0700 2200 The continuous equivalent sound level See definition is generally calculated on an hourly basis and is shown in the equation as L The values for the hourly periods from midnight to 7 a m have 10 added to them to represent less tolerance for noise during sleeping hours The same occurs from 10 p m to midnight They are energy summed and converted to an average noise exposure rating A logarithmic form of any measured physical quantity and commonly used in the measurement of sound and vibration Whenever the word level is used this logarithmic form is implied The decibel provides us with the possibility of representing a large span of signal levels in a simple manner as opposed to using the basic unit Pascal for acoustic measurements It is not possible to directly add or subtract physical quantities when expressed in decibel form since the addition of logarithmic values correspond to multiplication of the original quantity The word level is normally attached to a physical quantity when expressed in decibels for example Lp represents the sound pressure level The difference between the sound pressure for silence versus loud sounds is a factor of 1 000 000 1 or more and it is very unpractical to use these large numbers Therefore a measure that would relate to the number of zeros wo
110. asurement Counter 00001 FIGURE 6 4 Timed Stop Mode The run mode is indicated as Timed Stop Timed Stop has only one parameter time The measurement will run for the duration specified after which it will be stopped The range of time values which can be entered is 00 00 01 to 99 59 59 in the format hh mm ss To enter the Run Time use the CJ and_C keys to highlight the Time data field and press the key This will produce a cursor which can be moved left and right to different digit positions in the data field using the and keys as shown in Figure 6 5 FIGURE 6 5 Entering Time in Timed Stop Mode At any digit position use the 7 and keys to adjust the value over the range 0 to 9 When the desired value of time has been entered press the key to conclude the process Run Modes LxT Manual Stop When Stable Mode Entering Delta Level Entering Time LxT Manual 5 0 01 35 1 Time His Run Mode fStop When Stable Delta dB Time 00 00 20 hh mm ss FIGURE 6 6 Stop When Stable Mode The run mode is indicated as Stop When Stable Data fields are provided to define Delta and Time The Delta level is the maximum one minute change in overall average level i e Leg allowed for the measurement to be considered stable The Time is the duration that the measurement must run before the measurement can stop If the time were set to 0 the measurement would run until the stability condition
111. at the bottom of the page is the date and time the measurement was started Live Page 5 3 1 1 Octave Band Analyzer Optional The 1 1 Octave Band Analyzer display appears only when the instrument is loaded with the optional LxT OB3 firmware FLD 0 00 00 0 LxT_Data Live Overall SessionLog Ad 4 D Frequency Spectrum Bandwidth cota Frequency Weighting and Time for Spectrum Averaging Measurement Sound Frequency Averaging Subscripts Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 Note that the spectrum frequency weighting is selected independently from that of the sound level measurement as described in OBA Frequency Weighting on page 4 14 The detector is the same as that of the sound level measurement 5 4 i 1 1 Octave Frequency Band Level at Cursor Position Pressure Weighting and 100 Miil 60 20 1 00kHz Z Fast L 1 00kHz F LAF 44 1 dB 50 9 dB Level Started 2006 Jun 08 12 05 49 Indicted by FIGURE 5 3 Live Page Section 2 Section 2 shows a bar graph of sound level in 1 1 octave frequency bands The right most bar on the graph is the Lag It is indicated beneath the graph that it is in 1 1 octave bands On the graph the vertical bar for the selected octave band is highlighted The frequency of the octave band for which data is being displayed the sound pressure level frequency weighting A weight and the d
112. at the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 LxT Manual EY 0 00 05 9 Z S lin p viii E Lmin 34 4 dB FIGURE 5 10 Overall Page Section 4 The data displayed in Section 4 is similar to that displayed for a 1 1 octave spectrum measurement described in 1 1 Octave Band Analyzer Optional on page 5 4 except that it represents 1 3 octave data Overall Page 5 13 Dosimeter 1 and 2 5 14 OSHA 1 LTWAS O 28 6 dB LTWA 81 1 dB Lep d 55 7 dB DOSE 0 02 ProjDose 29 12 Weighting A Slow Exchange Rate 5 dB Threshold 90 0 dB Criterion 8 0 h 90 0 dB Run Time 0 00 19 8 FIGURE 5 11 Dosimeter 1 amp 2 Display Sections 5 and 6 There are two separate but similar dosimeter data displays in sections 5 and 6 In this example we can see that the measurement parameters correspond to the setup named OSHA 1 The Lateral Time Weighted Average for 8 hours is calculated for the predetermined Criterion Time in this case 8 hours The ProjDose Projected Time Weighted Average is calculated from data measured during the measurement run time The Daily Personal Noise Exposure Lep d is next on the display This is calculated from data measured during the run time of the measurement Dose is calculated for the predetermined Criterion Time and Criterion Level 100 definition Overall Page LxT Manual Projected Dose is calculated for the ru
113. atest measurement susceptibility to A C power frequency and radio frequency fields was with the LxT2 set to run USB cable attached and with an LxT EXC010 10 microphone extension cable between the PRMLxT2 and the LxT2 B 18 LxT2 LxT Manual APPENDIX Integrated Level Calculations Basic Integrated Level Calculations Equivalent Continuous Sound Level Note that the LxT displays the equiv alent continuous A weighted sound pressure level as Leg The Larson Davis SoundTrack LxT calculates equivalent continuous sound levels based on equations from IEC standard 61672 1 Section 3 9 which defines Leg as follows Equivalent continuous A weighted sound pressure level also average A weighted sound pressure level is defined as follows 1 2 Lat Lacar 201g 4 Zod P aB t T where L AeqT is the equivalent continuous A weighted sound pressure level re 20 Pa determined over a time interval T amp is a dummy variable of time integration over the averaging time interval ending at the time of observation t T is the averaging time interval p 8 is the A weighted sound pressure Model 831 Manual Integrated Level Calculations C 1 Note that the format used by the LxT to display equivalent continuous sound pressure level is Lx y where X is the frequency weighting X A Cor Z Time Weighted Averages C 2 Po is the reference sound pressure of 20 uPa In the equation the numerator of the argument of the
114. ator Power Indicator 3 2 A Screen comprises everything which can be seen on the display at one time There are four different screens available with the LxT which are described in more detail in the section Screens on page 3 12 The tabs indicate the active page as well as any other possible pages available in this view This is the main body of the screen The page contains the data to be viewed There may be more than 1 section for a page This is indicated on the scroll bar The scroll bar represents the complete page The section indicator shows the location on the page you are viewing One of the three possible images indicating the state of the battery charge or the external power connection icon will be displayed to indicate that the batteries or power supply are providing sufficient power to operate the meter within specifications Display Sections and Icons LxT Manual Measurement Name Stability Indicator Run Time Input Overload Icon OBA Overload Icon LxT Manual This is the file name to be used for the data file For certain measurement modes and for calibration an indication of the stability of the measured signal is presented in the following icon This is the amount of time the measurement has been running When a signal from the preamplifier exceeds the calibrated input range of the LxT the Input Overload Icon will appear While the overload is present the icon will flash on and
115. been measured in representative configuration with PRMLxT1 preamplifier 377B02 microphone and the following cables EXC010 microphone extension cable CBL138 USB interface cable and CBL139 AC DC output cable in accordance with the following directives e 89 336 EEC The Electromagnetic Compatibility Directive and its amending directives has been designed and manufactured to the following specifications EN 50081 1 1992 Electromagnetic compatibility Generic emission standard Part 1 Residen tial commercial and light industry EN 50082 2 1995 Electromagnetic compatibility Generic immunity standard Part 2 Industrial environment A 2 Technical Specifications LxT Manual LxT Specifications LxT Main Characteristics Class Precision Integrating Sound Level Meter with real time 1 3 Octave Filters classified as group X for the emission of and susceptibility to radio frequency fields 64 MB standard data memory 120 MB optional High contrast 1 8th VGA LCD display with white LED backlight sunlight readable Icon driven graphic user interface Soft rubber backlit keys Large dynamic range Time weightings Slow Fast Impulse Integration and Peak Frequency weightings A C Z 1 1 and 1 3 octave frequency analysis available Voice message annotation available which includes headset L statistics L0 01 through L99 99 available Blaze software available for setup control high
116. by the host This means that the LxT must run on batteries until allowed by the host to run on USB or external power If the batteries cannot provide sufficient power flat cells the LxT will not power on Ensure that the LxT has good batteries in order to turn on External Power Supply 16 7 PSA029 The PSA029 is supplied with mains power adaptors for most areas of the world Locate the plug adapter for your locality and install it by sliding it onto the supply case 16 8 The PSA029 external power supply for the LxT has an input operating voltage range of 90 to 274 VAC and a power line frequency range of 47 to 63 Hz The output voltage from the supply is 5 VDC The external power supply connects to the USB connector on the bottom of the LxT With the power supply connected and operating at rated conditions the LxT will operate properly with or without batteries installed If the LxT is operated on external power only no batteries installed there is a possibility of instrument malfunction if there is an interruption of power to the LxT for any reason External Power Supply LxT Manual Parameters Measured This chapter describes the different acoustic parameters which can be measured displayed and stored using the LxT Basic Sound Level Measurements Frequency Weighting See SLM Page on page 4 5 Each of the sound level parameters measured at one time will be frequency weighted as set by the user from the Measu
117. cannot be measured directly but can only be deduced through measurements of sound intensity or sound pressure around the source The equation for it is L EE Ww wao 0 The speed at which sound waves propagate It is measured in meters per second It should not be confused with sound or particle velocity which relates to the physical motion of the medium itself c 20 05 degC 273 m sec c 49 03 degF 460 ft sec The amplitude of sound or vibration at various frequencies It is given by a set of numbers that describe the amplitude at each frequency or band of frequencies It is often prefixed with a descriptor that identifies it such as sound pressure spectrum It is generally expressed as a spectrum level The A weighted sound level below which the sound produces little or no Noise Dose accumulation and may be disregarded It is used for hearing damage risk assessment Standard ANSI 81 25 Glossary D 21 Time Weighted Average Sound Level TWA Ltwatc Time Weighting Vibration Wavelength I It is the level of a constant sound over the Criterion Duration that would expose a person to the same Noise Dose as the actual unsteady sound over the same period If the Exchange Rate is 3 dB then the TWA is equal to the Leg T A 1 L t K where T T7 T and K is the Exchange Rate Factor It is used for hearing damage risk assessment Standard ANSI S12 19 The response speed of the detector in a
118. cation Softkey Selection of About Pages a p Standards Options FIGURE 3 11 Softkey Selection of About Pages The Right and Left Softkeys are used to scroll between the About Pages 3 20 Tools Screen LxT Manual CHAPTER Basic Measurement Setup This chapter describes the setup of the LxT to perform basic sound level measurements These measurements may include the following e Leq Lmax Lmin corresponding to user selected values of frequency weighting and detector e Lpeak and Lpeak max corresponding to a user selected value of frequency weighting e 1 1 and or 1 3 Octave real time spectra LxT OB3 required e Six values of Ln based on six user selected values of the parameter n e Count of the number of times the levels RMS and Peak exceeded user selected threshold values e Sound exposure and sound exposure level data The LxT can measure many additional sound parameters simultaneously with these basic sound measurements as described in subsequent chapters LxT Manual Basic Measurement Setup 4 1 Measurement Properties Screen Accessing the Measurement Properties Screen Settings In Use Message If the LxT is not already connected to a computer running Blaze or LxT Utility software ignore this section 4 2 The parameters defining a measurement are set from the Measurement Properties Screen This screen can only be accessed from the Data Views Press
119. cccnncnnnnnnncnnos 6 6 Daily TE 6 6 Single Block Timer Mode oooccccooocccccccccccoccccnos 6 7 Daily Timer Mode AANEREN 6 9 Chapter 7 Making a Measurement Configuration of the System eneeeaeneeaa 7 1 Switching On the INTE 7 2 Start up PEO AAA 7 2 AIR 7 4 RT 7 4 EAS Un dida 7 5 Calibrating the LX Finis ans 7 5 Positioning the LT 7 5 Observer Position ooooccccccoooccnnnonoconaccnnnnos 7 5 Microphone Extension Cable oooooocccccccccooo 7 6 Use of a Windscreen ccccccononcccnccccconccnoncnnnnnns 7 6 Performing the Measurement 7 8 Starting the Measurement coccccccccoooccccncconnnnconos 7 8 BAR EE 7 8 Measurement Range ccccccccncccccccccnnnocnnnncnnnaness 7 11 Overload Indication cis ai 7 11 Pausing the Measurement occcccccnnoccccnnncnnnncos 7 11 ii vi Resetting the Measurement 7 12 Resetting When Running or Paused cccceceeseeseceseeeeeereeseeneeenes 7 12 Resetting When Stopped irte teedenee tees tess 7 13 Starting a New Measurement 0 eececcesseesecseeeeceeeeteeeeeeseneeeeeeees 7 13 Stopping the Measurement 7 13 Storing the Measurement ooooccccccnccncccnoco 7 14 Overwriting a Saved File 7 15 Low Level Sound Fields 7 16 Chapter8 Voice Recording Control Page Voice Recording 8 1 Voice Recorder 8 2 SE EE 8 3 SAVE PLOMP EE 8 4 Serie 8 4 Chapter9 Time History Parameters Logged cccoocccccncococoncccucoconanoss 9 1 Acoustical
120. d When the LxT is in any of the lock modes and is stopped the unit may be calibrated This is only possible if the Allow Cal When Locked check box on the Lock Page has been checked previous to entering Lock mode See FIGURE 12 6 Allow Cal Check Box If the Center Softkey indicating CAL is active as shown in FIGURE 12 14 press this key This will bring up the calibration screen See Chapter 13 Calibration on page 13 1 for complete details on calibrating the LxT 0 00 00 0 Date 2006 Mar 20 17 23 49 This instrument has been LOCKED Press the Tools key to UNLOCK FIGURE 12 14 Locked with Calibration Permitted 12 14 Calibration When The LxT Is Locked LxT Manual Calibration Control Panel Calibrate LxT Manual To activate the Calibration function press the A TOOLS key Use the 7 Sor keys to highlight the Calibrate icon as shown below FIGURE 13 1 Control Panel Press the key to open the Calibrate Pages There are 3 Calibration Pages e Calibrate used to perform a calibration e History a list of the 10 previous calibrations e Certification Shows the last certification performed Calibration 13 1 Exiting from the Calibration Function Press the Close Softkey to exit from the calibration function Calibrate 5 0 01 00 0 i Calibrate Tool Calibrate IG e Calibrate Calibrator Description LD CAL200 114 0dB 1kHz LD CAL200 114 0dB 1kHz O LD
121. d Microphone and PRMLxT2 A nenne A 22 Directional Characteristics aii ir A 25 Noise Levels ia non tercio did A 27 n BEE E A 28 LxT1 PRMLXTIL With 27780 A 29 LXT2 PRMLXT2 with EE A 30 ii xii LxT2 PRMEXT2L with 7052 oien oirn ini ae A 31 Microphone Preamplifier Specifications A 32 Model PRMLXT1 E A 32 Sa CN A 32 Model PRMLXT1L ccccsseeeeceeeeeeesseeeeess A 37 ee A 37 Model RRMEXTZ Eeer ebe A 41 ege EE A 41 Model PRMLXT2L ccccsseeeeceeeeeeeseeeeeess A 46 Specifications ii in ads A 46 Appendix B Testing to IEC61672 1 B 1 Sections 5 6 7 and 9 except 9 3 B 1 E Url EE B 8 A TEE B 8 a Calibre as B 8 b Calibration Frequency ccccecceseesceeseeecesceesecseecsecsseeaeeneenseentens B 8 c Calibration Procedure iii sia B 8 d Frequency Response and Corrections 0ooooonoccocconoconcconconcnnncanonanonos B 9 A E B 10 a Reference Sound Pressure Level B 10 b Reference Level Range B 10 c Microphone Reference Pomt eccceeseeeeeeteeeeceeeeseeeeeeseeneeenes B 10 d Periodic Testing iia toas B 10 e Linear Operating Range B 11 f Linear Measurement Starting Level B 11 g Electrical Insert Sugenals ccccesesseesecesceeeeesceeeeeeceseeeeeeeeenes B 12 h Inherent Noise EE ENER EENS ENEE B 12 1 Highest Sound Pressure Level ccscesceesceseeeseeseeeeeeseeeseeneeenes B 12 j Battery Power Voltage Range B 12 k Display Devi cena ile ere its B 12 1 Typic
122. d instrument are at a temperature other than near room temperature or static pressures not near sea level then corrections will need to be added for the ambient temperature and the prevailing static pressure Check the calibration data shipped from Larson Davis with the CAL200 to get these corrections The corrections can be added to the level obtained in the previous paragraph to get the actual level of the CAL200 The 7052 microphone s sensitivity varies with static pressure If the instrument is calibrated in one environment and moved to another then the sensitivity will change after stabilization depending on the change of temperature and Calibrate LxT Manual Adding a Calibrator LxT Manual pressure The coefficient of static pressure is 0 036 dB kPa If the system is calibrated at 85 kPa for instance then it will be 0 57 dB less sensitive at sea level The sensitivity of the 377A02 and LxT varies slightly with temperature also The coefficient of temperature is 0 01 dB C If the system is calibrated at 18 C then it will be 0 05 dB less sensitive at 23 C The Larson Davis 3 Wind Screen has less than 0 05dB effect on the system response at kHz Set the CAL200 level switch to 94 or 114 dB When adding a calibrator to the list the following information may be entered e Calibration Level e Calibration Frequency e Calibrator Description The calibration level and frequency values are as specified in section C
123. dB Table 1 1 Microphone and Preamplifier LxT Manual Features 1 9 Other Optional Accessories Windscreen 3 1 2 in diameter WS001 Alkaline Batteries 4 AA Lanyard Qty 4 SS button socket head screws 4 40 x 3 16 to secure access to battery door when using in an explosive atmosphere Larson Davis part number 5290 0185 Hex Driver 1 16 miniature for use with battery door access screw LxT User Manual 1770 01 SLM Utility G3 software providing setup utilities calibration routines remote instrument control from PC data downloading and export of data to 3rd party software such as MS Excel SLMScreengrabber software to capture and save screen displays as bitmap files The LxT will conform to all referenced standards using any of these optional accessories Microphones 1 10 377B02 1 2 in Type 1 Free Field 50 mV Pa 7052 1 2 in Type 2 Free Field 20 mV Pa order MIC006 377A01 1 4 in Type 1 Free Field 4 mV Pa ADP043 1 4 microphone to 1 2 preamplifier adaptor required Features LxT Manual Microphone Preamplifiers e PRMLXxTI1 Type 1 with 14 dB capacitive attenuation e PRMLxT 2 Type 2 with 6 dB capacitive attenuation e PRMLxTI1L Low Level Type 1 with no attenuation e PRMLxT2L Low Level Type 2 with no attenuation Microphone and Preamplifier Configurations e PRMLxTI1 or PRMLxTIL with 377B02 e PRMLxT2 or PRMLxT2L with 7052 e PRMLxT1 or PRMLxT1L with 377A01 including ADP043 adapter Equi
124. disclaimer of implied warranties may not apply to certain purchasers I Procedure for Warranty Performance If the product fails to perform to LD s specifications the Buyer must provide LD with the applicable model and serial numbers the date of purchase and the nature of the problem J ADDITIONAL EXCLUSIONS FROM THIS LIMITED WARRANTY NOTWITHSTANDING ANYTHING TO THE CONTRARY CONTAINED IN THIS LIMITED WARRANTY THIS LIMITED WARRANTY DOES NOT COVER ANY OF THE FOLLOWING 1 EQUIPMENT THAT HAS BEEN ABUSED DAMAGED USED BEYOND RATED CAPACITY OR REPAIRED BY PERSONS OTHER THAN AUTHORIZED SERVICE PERSONNEL E 2 Warranty Customer Satisfaction LxT Manual 2 DAMAGE CAUSED BY ACTS OF GOD THAT INCLUDE BUT ARE NOT LIMITED TO HAILSTORMS WINDSTORMS HURRICANES TORNADOES SANDSTORMS LIGHTNING FLOODS AND EARTHQUAKES 3 DAMAGE UNDER CONDITIONS CAUSED BY FIRE OR ACCIDENT BY ABUSE OR BY NEGLIGENCE OF THE USER OR ANY OTHER PERSON OTHER THAN LD BY IMPROPER INSTALLATION BY MISUSE BY INCORRECT OPERATION BY NORMAL WEAR AND TEAR BY IMPROPER ADJUSTMENT OR ALTERATION BY ALTERATIONS NOT COMPLETED BY AUTHORIZED SERVICE PERSONNEL OR BY FAILURE OF PRODUCTS PARTS FROM SUCH ALTERATIONS 4 COSTS OF REPAIRING DAMAGE CAUSED BY POOR OR IMPROPER MAINTENANCE OR UNAUTHORIZED REPAIR 5 COSTS OF MODIFYING THE PRODUCT IN ANY WAY ONCE DELIVERED TO THE BUYER EVEN IF SUCH MODIFICATIONS WERE ADDED AS A PRODUCTION CHANGE ON OTHER PRODUCTS MADE AFTER THE BUY
125. e graph represents the value of Leq as a function of time during the measurement LxT Manual Performing the Measurement 7 9 7 10 Leq Running SPL Running Lpeak Maximum Lpeak with data and time of occurrence Maximum RMS Value with date and time of occurrence Minimum RMS Value with date and time of occurrence Measurement Duration LD 0 00 18 0 ER LxT_Data EES Overall EST OK Laseg 72 2 dBES Las 34 2 dB L2peak 64 1 dB L2peak max 91 9 dB 2006 pr 23 16 44 29 LASmax 80 3 dB 2006 Apr 23 16 44 30 LASmin 32 1 dB 2006 Apr 23 16 44 18 Run Time 0 00 18 0 FIGURE 7 7 Multiple Sound Level Parameters Performing the Measurement LxT Manual Measurement Range Overload Indication Pausing the Measurement Note that a measurement may be paused and then run again multiple times LxT Manual The measurement ranges over which the LxT meets the standards which depend upon the selected frequency weighting are shown in Table A 11 LxT Performance Specifications on page A 9 Measurements which include levels outside this range should not be considered accurate An overload indication will appear when levels above the range appear However the user should take care not to rely on measurements whose levels are below the lower limit of the specified range When a signal from the preamplifier exceeds the calibrated input range of the LxT the Input Overload Icon will appear at the top of the display
126. e Unlock The LxT is unlocked and all functions are available to the user LxT Manual Locked With Auto Store 12 11 Locked With Manual Store 12 12 If the Locked w Manual Store mode has been selected upon accepting the changes on the Lock Page the view would be as shown in FIGURE 12 10 Locked with Auto Store or Manual Store In this mode a measurement is started by pressing the Ei RUN PAUSE key Pressing the ra RUN PAUSE key a second time will pause the measurement and pressing it again will continue the measurement The CR STOP STORE key will stop a measurement and a pressing it a second time will initiate the storage process by displaying the Save File prompt as shown in FIGURE 12 13 Save File Sat Data Oe LAeq 23 2 dBEA Las 28 1 dB LASmax 74 8 dB Started 2006 Apr 20 10 30 21 FIGURE 12 13 Manual Store When Locked Left click Yes to store into the file number indicated No to abort the storage operation or to overwrite a file into which data has already been stored Locked With Manual Store LxT Manual Unlock LxT Manual To unlock the LxT press the A TOOLS key the key or the Right or Left Softkey Enter your 4 digit code then press the Lt key See FIGURE 12 10 Locked with Auto Store or Manual Store The LxT is unlocked and all functions are available to the user The measurement may be stored Locked With Manual Store 12 13 Calibration When The LxT Is Locke
127. e as 40 eq 1s Lpeak 58 5 dB 89 4 dB 2 199 4 2006 Jun 08 17 18 07 Record FIGURE 9 6 LxT Manual Time History Display 9 9 Frequency Spectra Display When either of the optional firmwares LxT OB1 or LxT OB3 have been enabled and either the 1 1 octave spectra or the 1 3 octave spectra or both have been selected to be logged in the time history then frequency spectra will appear in the list of parameters which can be displayed 9 10 In the list of parameters which can be logged with a time history measurement frequency spectra will appear as a group beginning with the 9th item in the list For example if both 1 1 and 1 3 octave spectra have been activated for the measurement the following frequency spectra will appear in the selection list as items 9 through 14 OBA 1 1 Leq e OBA 1 1 max e OBA 1 1 min e OBA 1 3 Leg OBA 1 3 max e OBA 1 3 min Time History Display LxT Manual 1 1 or 1 3 Octave Spectra When only one type of frequency spectrum 1 1 or 1 3 octave has been selected to be logged the basic time history graph might look at shown in FIGURE 9 8 Sess Press Gei Enter key to display 1 3 SSC octave frequency spectra 006 Apr 24 09 40 12 Enter gt By 1 3 Frequency FIGURE 9 8 Time History Display with Frequency Spectrum Data Logged The Enter key is now used to In the above figure we see a new a text message at the toggle the display between Time bottom of th
128. e by one the parameters to be stored for each time increment Use the ED key to highlight the Time History Options window and press the key The first item in the options list will be highlighted as shown in Figure 9 4 Time History Options Close FIGURE 9 4 Time History Options Window Use the gt and C keys to move the highlight down or up respectively and use the Q or O key to select an option and place a check in the check box Use the same keys to deselect a box already checked hen the options have been designated as desired press the key to exit from the Time History Options Menu You will then be able to display other pages of the Measurement Setup Menu or exit from the Measurement Setup Menu by pressing the center softkey labeled Close Time History Setup LxT Manual Time History Display Single Value Parameters When the LxT is not equipped with In this section we discuss the time history graph which the optional firmware LxT OBI or appears for single value parameters such as sound levels LxT OB3 or if it is equipped with and non acoustic parameters this option but the measurement of 1 1 and 1 3 octave spectra has been set Time History data is displayed on the Time History tab page to Off in the measurement setup all of the Data Display View as shown in Figure 9 5 measured parameters will be single value parameters Time History Graph 1 14 4 2006 Jun 08 15 33 46 Data and time of keypress begin
129. e geometric far field A sound field that is free of reflections This does not mean that the sound is all coming from one direction as is often assumed since the source of sound may be spatially extensive See the definitions of near and far fields for more detail This definition is often used in conjunction with reverberant field The rate at which an oscillating signal completes a complete cycle by returning to the original value It can be expressed in cycles per second and the value has the unit symbol Hz Hertz added and the letter f is used for a universal descriptor It can also be expressed in radians per second which has no symbol and the greek letter is used for a universal descriptor The two expressions are related through the expression w 2ITf The part of certain sound level meters that divides the frequency spectrum on the sound or vibration into a part that is unchanged and a part that is filtered out It can be composed of one or more of the following types Glossary D 9 Frequency Filter Weighted D 10 Low Pass A frequency filter that permits signals to pass through that have frequencies below a certain fixed frequency called a cutoff frequency It is used to discriminate against higher frequencies High Pass A frequency filter that permits signals to pass through that have frequencies above a certain fixed frequency called a cutoff frequency It is used to discriminate against lower frequencies Band
130. e measurement is initiated manually by pressing the E Run Pause key The measurement will stop when the measured level has remained within a user defined range and the measurement has run for a user defined time period Left click the down arrow in the Run Mode data field to open the Run Mode Menu Lana Stop sl Manual Stop Timed Stop Stop When Stable Continuous Single Block Timer Daily Timer FIGURE 4 15 Run Mode Menu To set the mode use the CI and keys to highlight the mode desired and press the key to make the selection The screen will then look as shown in Figure 4 16 Figure 4 17 or Figure 4 19 depending upon the mode selected For the Timed Stop and Stop When Stable modes further information must be entered Dosimeter 1 and 2 Pages 4 17 Manual Stop Mode Timed Stop Mode 4 18 5 0 00 00 0 ZS D i fet Control kr Run Mode Manual Stop MM FIGURE 4 16 Manual Run Mode The run mode is indicated as Manual Stop no further information is required Time Hisi Run Mode Timed Stop v ime 00 00 20 hh mm ss FIGURE 4 17 Timed Stop Run Mode The run mode is indicated as Timed Stop Timed Stop has only 1 parameter time The measurement will run for the duration specified after which it will be stopped The range of time values which can be entered is 00 00 01 to 99 59 59 in the format hh mm ss Entering Run Time To enter the Run Time use the 7 and keys to highlig
131. e screen with the message Enter gt By 1 3 History and Frequency Spectrum Frequency indicating that the key is to be pressed to display a 1 3 frequency spectrum If the spectrum type being logged is 1 1 octave the message would read Enter gt By LI 1 Frequency LxT Manual Time History Display 9 11 If without pressing the Enter key we press the T key until the displayed parameter becomes OBA 1 3 Leq the display will look as shown in FIGURE 9 9 P 0 00 31 3 Ka LxT_ Data MESA Time History SS Level of Lowest Frequency Band in Spectrum OBA 1 3 Leg Record 2 34 4 2006 Apr 24 09 40 12 Frequency Spectrum as Enter gt By 1 3 Frequency L Displayed Parameter FIGURE 9 9 Time History Display with Frequency Spectrum as Displayed Parameter Although the displayed parameter is a frequency spectrum the graph remains that of the Leq time history The level displayed is that of the lowest frequency band of the spectrum In order to display the spectrum itself press the Enter key as called for by the text message Enter gt By 1 3 Frequency This will change the display to that of the frequency spectrum corresponding to the displayed parameter as shown in FIGURE 9 10 9 12 Time History Display LxT Manual Use O and O keys to shift the cursor right or left respectively Press Enter key to display time history data 0 00 17 8 i LxT_Data METIA Time History Wor Displaying
132. e selection The LxT supports two formats for expressing dates e day month year e year month day Use the 7 and Z keys to highlight the Date Format field and press the key to obtain a listing of the choices as shown in FIGURE 11 9 Date Format uto Store FIGURE 11 9 Date Format Preferences Use the 7 and CH keys to highlight the desired Date Format and press the ena key to make the selection Preferences LxT Manual Auto Store None Prompt LxT Manual The LxT provides three Auto Store options to enhance your data gathering activities e None e Prompt e Store Use the 7 and C2 keys to highlight the Auto Store field and press the key to obtain a listing of the choices as shown in FIGURE 11 10 Auto Skore Mone Jack Function None USB Storage FIGURE 11 10 Auto Store Preferences Use the 7 and gt keys to highlight the desired Auto Store option and press the key to make the selection The user must press the 22 STOP STORE key to Stop the measurement Press it again to store the data and also assign a filename See Storing the Measurement on page 7 14 When the 22 STOP STORE key is pressed to stop a measurement the user will be prompted to save the data file See Storing the Measurement on page 7 14 If the user responds Yes then a data file is saved If No is selected a data file is not saved If data was stored when the Y RUN PAUSE key is pressed the instrument is au
133. e top of the display Press the D key to Dosimeter 1 and 2 Pages LxT Manual drop down a list of predefined setups by name as shown in FIGURE 4 6 Predefined Dose Setups lt gt 0 00 00 0 ER Settings A Dosimeter1 gt Name OSHA 1 el Exchange Rate Threshold E Enabled 090 0 dB Criterion 090 0 dB 08 0 Hr O Auto Calculate Close FIGURE 4 6 Predefined Dose Setups Use the 7 and keys to highlight the name of the desired setup and press the 10 Key to make the selection The name of this setup will now appear in the Name field and all parameters will be set according to the setup selected as shown in FIGURE 4 7 IEC LxT Manual Dosimeter 1 and 2 Pages 4 9 0 00 00 0 GER Dosimeteri fe Name IEC y Exchange Rate Threshold DEnabled Criterion 085 0 de Hr Dauto Calculate FIGURE 4 7 IEC Parameters Individually Defined Name Field If a predefined setup has been selected and any of the preset parameters are modified the user should consider changing the name of the setup 4 10 In the Dosimeter Page there are two fields Name and Exchange Rate and two sections Threshold and Criterion The Name field is optional although many users will enter text associated with the measurement to be performed such as a specific company Dose standard My Dose or the name of a standard not in the list To enter a name use the C and keys to highlight the Name field Use the
134. e used for noise floor measurements by attaching the included short on the front of the ADP005 h Inherent Noise Inherent Noise of the LxT1 Weighting Total Noise Electrical Noise A 28 28 c 28 27 Fit 32 31 combination of the electronic noise and the thermal noise of the microphone at 20 C measured in a sealed cavity and vibration isolated electronic noise of the instrument with an ADP005 in place of the microphone i Highest Sound Pressure Level The highest sound pressure level the Larson Davis LxT1 is designed to accommodate at the level of overload is 140 dB The peak to peak voltage at this level is 28 Vpp input through the ADP0OS j Battery Power Voltage Range The battery power supply voltage range for which the LxT1 conform to this standard 6 4 Volts maximum The LxT will shut down if the battery is below 4 0 Volts when used with alkaline batteries Therefore from 4 0 to 6 4 Volts is the usable range of battery voltage k Display Device The display device will display all levels over the entire linear operating range I Typical Stabilization Time The typical time interval needed to stabilize after changes in environmental conditions B 12 LxT1 LxT Manual For a temperature change of 5 C then 30 minutes are required For a static pressure change of 5 kPa then 15 seconds are required For a humidity change of 30 non condensing then 30 minutes are required m Field Strength
135. eamplifier 16 2 DIS EES 16 2 Keypad tsannealed E 16 3 SEET 16 3 ee 16 4 Connectors and Intertoaces eee 16 5 Batteries ooccccnnccocncoonicocnconnnconiconononnnonons 16 6 External Power Supply occcocccccoccccocccccnoo 16 7 PSA EE 16 8 Chapter17 Parameters Measured Basic Sound Level Measurements 17 1 Frequency Weohtng reenen 17 1 RMS Averaging NEEN 17 2 Sound Level Metrics Measured n01nnn000nnn 17 3 1 1 and or 1 3 Octave Frequency Spectra 17 3 Sound Exposure Metrics Measured 17 4 Statistical Metrics Measured ann0nn0annn 17 5 li xi Miscellaneous Parameters occcoocccccccccc 17 6 A ea 17 6 Chapter 18 Memory Utilization Overall Dalai cc iia 18 1 SS AA 18 1 Time e Ire casino dao 18 2 Voice Messages 18 2 AppendixA Technical Specifications A 1 Standards Met EE A 1 Declaration of Conformity occcccccconnnccnncccnnnoos A 2 age ere LEE A 3 1 1 and 1 3 Octave tlters A 11 Frequency Range seniii eni na i EE E EE E A 11 Le A 11 Position of Instrument and Operator A 14 Effect of Wumdecreen A 14 Windscreen Response with Respect to No Windscreen 0 A 14 Frequency Response occcooccccncccccnonnconcncnon A 16 LxT With 377B02 Free Field Microphone and PRMLxT1 Preamplifier ooocooooonncccnccc A 16 Directional Characteristics ccccecssesccsseesecesceseeesceseeeeceseeeseeneeenes A 19 LxT With 7052 Free Fiel
136. eamplifier was tested at a level of 1 157 Vrms with 18pF microphone capacitance and driving a short cable Output level at 1kHz is 1 0167 Vrms 0 144 dBV uncertainty 0 035 dB Output is 3 664 V DC uncertainty 0 001 Results are displayed relative to the level at 1kHz 0 5 50 Measured dB Uncert dB Tolerance dB 0 oOoeooeeoeoeooeooeoeoooeoeooeooeooeoc 0 0 0 100 49 32 225 ee 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Kail 04 01 03 05 06 07 08 08 08 09 09 09 09 09 09 09 10 10 10 200 1 01 0 73 0 50 0 36 0 28 0 21 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1000 1995 5012 10000 19953 Frequency Hz 100000 126000 oOoeooeeoeoeooeooeooooeoeooeooeooec Noise floor data 1kHz 1 3 Octave 0 45 uV 7 0 dBuV uncertainty 0 47 dB Flat 20Hz 20kHz 3 5 uV 10 9 dBuV uncertainty 0 47 dB Awt 1 7 uV 4 8 dBuV uncertainty 0 46 dB Uncertainties are given as expanded uncertainty at 95 confidence level k 2 Technician Jason Grace Test Date 050CT2005 FIGURE A 18 Certificate of Conformance PRMLxT1L Technical Specifications Tolerance dB 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
137. easurement Properties Screen each identified by a title on a tab at the top as shown in Figure 4 2 LE 0 00 00 0 D settings General GL HM MAA BG Frequency Weighting 4 E Oz FIGURE 4 2 Tabbed Setup Pages For basic measurements we will only be concerned with the following pages e General es SLM Dosimeter 1 Dosimeter 2 e Ln e OBA e Control e Triggers The Right and Left Softkeys are used to scroll through the available pages to the right and left respectively in the order they are listed above Setup Pages 4 3 General Page Note The LxT Utility Software can be used to easily enter both the file name and the measurement description 4 4 Each of these is described in detail in the sections which follow General ETGEN Default Data File LxT_Data Measurement Description FIGURE 4 3 General Page The General Page is used to enter a file name and a measurement description for the measurement being defined Upon opening the Default File Name LxT_Data may appear in the file name field To enter a new file name highlight the Default File Name text box and press the res key Use the Q O C and CH keys to enter a new name The key is pressed to complete the entry process Setup Pages LxT Manual SLM Page Frequency Weighting Time Weighting LxT Manual lt gt 0 00 00 0 E General SM Dosimeter1 DO Frequency Weighting ela Oc oz Detector Slow
138. ecifications The specifications contained in this chapter are subject to change without notice Please refer to calibration and measurement results for data on a specific unit Standards Met The LxT meets the specifications of the following standards Instrument LxT1 LxT2 Sound Level Meter Standards IEC61672 1 2002 05 Class 1 Group Z IEC60651 1979 plus Amendment 1 1993 02 and Amendment 2 2000 10 Type 1 Group Z IEC60804 2000 10 Type 1 Group Z ANSI S1 4 1983 R 1997 plus Amendment S1 4A 1985 Type 1 ANSI S1 43 1997 Type 1 IEC61672 1 2002 Class 2 Group Z IEC60651 1979 plus Amendment 1 1993 02 and Amendment 2 2000 10 Type 2 Group Z IEC60804 2000 10 Type 2 Group Z ANSI S1 4 1983 R 1997 plus Amendment SI AA 1985 Type 2ANSI S1 43 1997 Type 2 Octave Filter Standards Options OB1 or OB3 only IEC61260 1995 07 plus Amendment 1 2001 09 1 1 and 1 3 octave Bands Class 1 Group Z all filters ANSI S1 11 2004 Class 1 IEC61260 1995 07 plus Amendment 1 2001 09 1 1 and 1 3 octave Bands Class 1 Group Z all filters ANSI S1 11 2004 Class 1 Personal Noise Dosimeter IEC61252 Ed 1 1 2002 Type 1 IEC61252 Ed 1 1 2002 Type 2 Standards ANSI S1 25 1991 Class 1 ANSI S1 25 1991 Class 2 Table A 1 Standards Met by LxT LxT Manual Technical Specifications Declaration of Conformity Larson Davis Inc declares that LxT Sound Level Meter has
139. eck Disk on a PC If a problem is detected an attempt will be made to repair the problem Selecting this function will format the internal data storage area in the memory of the LxT This operates similar to the Format function on a PC System and measurement properties are preserved Selecting this function formats the internal data storage area in the memory of the LxT The LxT is then restored to factory settings The Format and Format amp Restore Defaults function will erase all internal data files but it will not affect data stored in USB memory File System 15 3 15 4 File System LxT Manual CHAPTER LxT Hardware Components Microphone Microphone Preamplifier 160 X 240 Graphic LCD Display Context Sensitive Softkeys Fixed Function Hardkeys FIGURE 16 1 LxT Front View LxT Manual LxT Hardware 16 1 Microphone and Microphone Preamplifier Display 16 2 There are three models of microphone and four preamplifiers available for use with the LxT There are two equivalent electrical impedance adaptors available These are discussed in Chapter 1 Optional Accessories on page 1 10 The LxT has a 160 x 240 graphic liquid crystal display The display is backlit to provide comfortable viewing in most ambient light situations Controls are provided for contrast and backlight adjustments These controls are discussed in Chapter 3 Power Control Page on page 3 7 and Chapter 11 Power on page 1
140. ed using the frequency weighting and averaging selected during the measurement setup as described in SLM Page on page 4 5 can be logged e Leq Lmax e Lmin Peak Level Values of Lpeak measured using the frequency weighting selected during the measurement setup as described in SLM Page on page 4 5 can be logged Time History 9 1 Specialized Acoustic Parameters Larrms Taktmaximal 5 utilized in Germany using A weighting and Fast detector This also requires selection from the Preferences page Takt Maximal Data on page 11 13 Liya and Liya2 time weighted averages associated with Dose 1 and Dose 2 exchange rates and thresholds See Dosimeter 1 and 2 on page 5 14 s LCSeq LASeq 1 1 and 1 3 Octave Spectra The optional firmware LxT OB1 or When the LxT OB1 firmware is enabled the following LxT OB3 is required for these frequency spectra can be logged parameters to be measured OBA 1 1 Leg OBA 1 1 max OBA 1 1 min When the LxT OB3 firmware is enabled the following frequency spectra can be logged OBA 1 1 Leq OBA 1 1 max e OBA 1 1 min e OBA 1 3 Leg OBA 1 3 max e OBA 1 3 min 9 2 Parameters Logged LxT Manual Non Acoustical Parameters From LxT Time History Setup LxT Manual Battery Level Internal Temperature Time History is setup using the Time History tab page of the Measurement Setup View as shown in Figure 9 1 A fret Wife Time History Py E
141. ed to an average noise exposure rating It is the time required for a constant sound level equal to the Criterion Level to produce a Noise Dose of 100 Criterion Duration is typically 8 hours Example If the Criterion Level 90 dB and the Criterion Duration is 8 hours then a sound level of 90 dB for 8 hours will produce a 100 Noise Dose See Noise Dose Standard ANSI S12 19 The product of the Criterion Duration and the mean square sound pressure associated with the Criterion Sound Level when adjusted for the Exchange Rate It is expressed in Pascals squared seconds when the exchange rate is 3 dB where q is the Exchange Rate Factor See Exchange Rate L q CSE T 10 Standard ANSI S1 25 It is the sound level which if continually applied for the Criterion Duration will produce a Noise Dose of 100 The current OSHA Criterion Level is 90 dB Standard ANSI 12 19 It is the level of a constant sound over the Criterion Duration that contains the same sound energy as the actual unsteady sound over a specific period The period is generally shorter so the sound energy is spread out over the Criterion Duration period Example If the Criterion Duration 8 hours and the specific period is 4 hours and the average level during the 4 hours is 86 dB then the Lep q 83 dB A rating of community noise exposure to all sources of sound that differentiates between daytime and nighttime noise exposure The equation for it is Gloss
142. efault times for these periods are as follows e Day 07 00 to 19 00 e Evening 19 00 to 23 00 e Night 23 00 to 07 00 Lday Levening and Lnight are A weighted long term average sound levels measured during the day evening and night respectively C 10 Integrated Level Calculations Model 831 Manual CNEL To account for the increased impact of environmental noise during the evening and night penalties are added to the measured level 5 dB for evening and 10 dB for night as can be seen in the equation The Directive 2002 49 EC of the European Parliament and of the Council of 25 June 2002 relating to the assessment of environmental noise permits member states to shorten the evening period by one or two hours and lengthen the day and or the night accordingly and also to choose the time for the start of the day To accommodate these and other possible modifications the Day Night page permits the user to modify the times for the beginning of the Day Evening and Night periods and the penalties to be utilized when calculating 24 hour integrated values In the state of California a commonly used community noise descriptor is Community Noise Equivalent Level CNEL defined by the following formula 1900 2200 2400 1 L 10 10 L 10 L 5 10 L 10 10 CNEL woso 77 A DI DI i Model 831 Manual 0700 1900 2200 This is essentially the same as the Lpgy using default values with the exception that the evening peri
143. el the Larson Davis LxT2 is designed to accommodate at the level of overload is 139 dB The peak to peak voltage at this level is 10 7 Vpp input through the ADP005 j Battery Power Voltage Range The battery power supply voltage range for which the LxT2 conform to this standard 6 4 Volts maximum The LxT will shut down if the battery is below 4 0 Volts when used with alkaline batteries Therefore from 4 0 to 6 4 Volts is the usable range of battery voltages k Display Device The display device will display all levels over the entire linear operating range I Typical Stabilization Time The typical time interval needed to stabilize after changes in environmental conditions For a temperature change of 5 C then 30 minutes are required For a static pressure change of 5 kPa then 15 seconds are required For a humidity change of 30 non condensing then 30 minutes are required LxT Manual LxT2 B 17 m Field Strength gt 10 V m The Larson Davis model LxT2 was not measured for field strengths greater than 10 V m n Radio Frequency Emission The mode of operation of the LxT2 that produced the greatest measurement radio frequency emission levels was with the LxT2 set to run and with an Lx EXC010 10 microphone extension cable used to connect the PRMLxT2 to the LxT2 Adding the USB cable did not emit more radio frequencies levels o AC Power and Radio Frequency Susceptibility The mode of operation of the LxT2 that produced the gre
144. elected for the sound level meter function described in Integration on page 4 6 Dosimeter 1 and 2 Pages 4 15 Exponential SLM Integration When using exponential integration for the sound level meter all 1 1 and 1 3 octave spectrum values are based on the same exponential time weighting Slow or Fast selected for the sound level measurement Linear Integration When using linear integration for the sound level meter the Leq value is determined digitally there is no exponential averaging However the Lmax and Lmin values are determined using the same exponential weighting Slow or Fast selected for the sound level measurement Control Page a gt 0 01 35 1 i TS Control iene gt Run Mode Manual Stop e Close FIGURE 4 14 Control Page A detailed description of the Run The Control Page is used to set the Run Mode for the Mode is presented in Chapter 6 Run measurement to be performed There are six modes of Control on page 6 1 measurement duration available In this chapter we will address only the first three 4 16 Dosimeter 1 and 2 Pages LxT Manual LxT Manual e Manual Stop The measurement is initiated manually by pressing the 220 Run Pause key and it is paused upon pressing the EZ Run Pause key a second time Timed Stop The measurement is initiated manually by pressing the Run Pause key and will be stopped automatically after a user defined time period e Run Until Level Stable Th
145. en unlocking this unit O llow Cal When Locked FIGURE 12 2 Lock Page Using the 7 E C keys highlight the Lock Mode list box Press the as key to drop down the list 5 0 00 00 0 0 Lock Mode Unlocked Unlock CdLock w Auto Store Enter a 9Lock w Manual Store when un Fully Locked O allow Cal When Locked FIGURE 12 3 Lock Mode List Use the or_ keys to highlight the desired lock mode Press the key to accept the selection 12 2 Control Panel Lock LxT Manual Lock Modes Unlocked Lock w Auto Store Lock w Manual Store In this mode the Auto Store preference is disabled see Chapter 11 Preferences on page 11 8 Fully Locked LxT Manual The user has complete access to the features of the instrument The user cannot change the data view in this mode Only the status line at the top of the screen is updated A measurement may be running when this mode is enabled or pressing the ay RUN PAUSE key will begin a measurement A measurement cannot be paused Pressing the CR STOP STORE key stops the run and stores the data but does not reset the measurement See Chapter 12 Locked With Auto Store on page 12 9 The user cannot change the data view in this mode Only the status line at the top of the screen is updated Measurements may be run paused and stopped See Chapter 12 Locked With Manual Store on page 12 12 The user has no access to the instrument except to start a run Auto Sto
146. er Softkey now labeled Close The Power Control Screen is opened by pressing the ON OFF key while in a Data View screen To exit from the Power Control screen press the Center Softkey labeled Close Screens 3 13 Data Display Screen For a more detailed description of the Data Display Screen and its associated Views see Chapter 5 Basic Data Display on page 5 1 3 14 There are four Data Views in the Data Display Screen identified by their titles on the tabs at the top of the screen as follows e Live Data is continuously displayed in this view whether there is a measurement in progress or not e Overall The data displayed in this view represents data measured and averaged beginning from the time the measurement was started by pressing the Run key until the elapsed time indicated above the display If the Pause or Stop key is pressed the elapsed time will be stopped However pressing the Run key again will continue this overall measurement as shown by the elapsed time restarting from the time when it had previously been paused or stopped e Session Log The Session Log is a record of data accumulation actions A time stamped record is made for every Run Pause Stop or Voice Message action Time History optional This view displays data measured using the time history measurement feature Screens LxT Manual Softkey Selection of Views mm Live Overall Session Log Time History
147. esponses and Correc tions on page B 8 5 2 5 9 2 4 d Frequency Responses and Correc tions on page B 8 5 2 6 9 2 4 d Frequency Responses and Correc tions on page B 8 5 2 7 d Periodic Testing on page B 9 5 2 8 d Periodic Testing on page B 9 5 4 12 No optional frequency responses 5 5 9 f Linear Measurement Starting Level on page B 10 5 5 10 f Linear Measurement Starting Level on page B 10 5 5 11 k Display Device on page B 11 5 6 1 h Inherent Noise on page B 11 5 6 2 h Inherent Noise on page B 11 5 6 3 LxT Performance Specifications on page A 9 5 6 4 LxT Performance Specifications on page A 9 5 6 5 Low Level Sound Fields on page 7 16 Sections 5 6 7 and 9 except 9 3 LxT Manual Section LxT Manual Comments 5 10 1 Overload Indication on page 7 11 and Maximum Minimum and Peak Sound Levels on page 5 9 5 11 1 See comment for section 5 11 2 5 11 2 LxT measures sound level using a single range The lower limit for level linearity error is caused by the inherent noise from the microphone and electronic ele ments within the sound level meter 5 12 1 LxT Performance Specifications on page A 9 5 14 Triggers Page on page 4 20 5 15 2 Basic Data Display on page 5 1 5 15 3 Display on page 16 2 5 15 4 Basic Data Display on page 5 1 5 15 5 General Specifications on page A 4 5 15 6 Integration on page 4 6 5 15 7 Sof
148. etector response Slow are also shown La ooxHz s indicates the sound level in the 1 kHz band with a Slow detector setting Lag is the A weighted Slow detector response sound level Live Page LxT Manual Cursor Use the Q and O keys to move the cursor left and right respectively 1 3 Octave Band Analyzer Optional The 1 3 Octave Band Analyzer display appears only when the instrument is loaded with the optional Lx T OB3 firmware Live UNE an r mi P E 140 Ki vol Hina 1 3 Octave 63 0 Hz Fast L 63 0Hz F 65 5 dB LAF 50 4 dB Started 2006 Jun 08 12 05 49 FIGURE 5 4 Live Page Section 3 Note that the graph scaling can be Section 3 is similar to FIGURE 5 3 Live Page Section 2 modified as described in section The graph and data are presented for 1 3 octave bands Adjust Graph Scale on page 5 23 LxT Manual Live Page 5 5 Triggering For a description of the setup of these trigger values see Triggers Page on page 4 20 5 6 lt gt 0 02 98 2 gt FIGURE 5 5 Live Page Section 4 Section 4 displays the sound level and peak level with their associated trigger points Exceedances of these trigger points will be indicated by a check mark appearing to the right of each The check mark will appear only as long as the measured level remains above the trigger point Live Page LxT Manual Time Battery Voltage and Memory 5 0 00 10 2 831_Data Live IZEG Date 2006 Ma
149. etucesdechceeceebidecss 13 2 New Calibrator 0 A e Snes 13 6 Caliprating EE 13 7 et KR lag tte EE 13 8 O eea a re eh 13 9 Certification Paga A Alans Gh eaa e 13 10 ADOUT a O 14 1 Control Panel EE 14 1 ee Te GC 14 2 Standards PAGS EE 14 3 len 14 4 User Page xan ees ee eee aia icine eit tee ee 14 5 iii v CROCS a ee ee eee etna eee aeons ernie 14 6 System Utiles oo ii 15 1 Control Pane EE EEN 15 1 File SY E 15 2 LxT Hardware ccceccecseceececceseecuseueeeeuscuseueeveuseeseees 16 1 LATE FOM VIEW O id 16 1 E ag EE 16 3 ExT BOUOM Panel acini ere in esas 16 5 Battery Status ICONS coonoconnnnnnnnncccccconcconnnnenenennnncnnninnnnnnnnnnncacanos 16 6 External Eine Ee e EE 16 7 Parameters Measured oococcocccoccoccnconncancanconcaninnons 17 1 Memory Utilization kk 18 1 Passband of 1kHz 1 1 Octave Filter A 12 Filter Skirts of 1KHz 1 3 Octave blier A 13 Effect of Wind Screen 0x Incidence 0 cee ceeccceecceeeeeeeeeeseeeeunees A 14 Effect of Wind Screen 90x Incidence cece cece eecceeeceeeeeeeeeeeeeees A 15 LxT with 377B02 Microphone 0 60 120 and 180 degree A 16 LxT with 377B02 Microphone 15 75 and 135 degrees A 17 LxT with 377B02 Microphone 30 90 and 150 degrees A 17 LxT with 377B02 Microphone 45 105 and 165 degrees A 18 LxT with 377B02 1000 00 Hz 1995 26 Hz 3981 07 and 7943 28 HzA 19 LxT with 377B02 Microphone 1258 93
150. f the sound arriving at the measurement microphone LxT Manual Voice Recording 8 1 Voice Recorder 8 2 Yoice 1 3 2006 Mar 05 20 45 34 Keypress Measurement 2006 Mar 05 20 45 44 2 2006 Mar 05 20 45 58 FIGURE 8 2 Voice Recorder The Voice Recorder Page will present a list of existing voice records The scroll bar and section indicator depict where you are in the list of files Using the 7 and US keys scroll through the list of voice records You may playback the highlighted voice record through a headset speaker by pressing the Right Softkey When measurement data is stored all voice records that are shown on the list will be stored in the data file The voice records list will then be empty Voice Recorder LxT Manual Record LxT Manual With a headset and microphone attached to the headset jack on the bottom of the LxT a voice record can be made Record Button Le Press the Left Softkey to begin recording The Recording message box will appear The meter indicates the relative signal level from the recording microphone and the progress bar shows the elapsed time of the measurement The progress bar length represents 20 seconds which is the maximum time for a voice recording 0 00 00 0 Voice Recorder FIGURE 8 3 Recording Voice Recorder 8 3 Save Prompt Playback 8 4 Press the key to stop recording if 20 seconds has not elapsed At the end of 20 seconds recording will stop automa
151. for reasons described in this section 2 8 The LxT can be powered from batteries or if available from the USB host portion of your computer It can also be powered externally using the PSA029 power supply as described in the section External Power Supply on page 15 7 When batteries are installed USB power is negotiated with the host and cannot be utilized until permission is granted by the host This means that the LxT must run on batteries until allowed to run on USB power by the host If there are no batteries installed in the LxT USB power will be utilized without host permission Thus make sure that the batteries can provide sufficient power for the LxT to turn On Otherwise remove the batteries and turn on the LxT using USB power Using USB Power LxT Manual Overview Display and Softkeys When the LxT is first switched on the Data Display Screen will appear When a measurement is in progress it will look similar to FIGURE 3 1 Data Display Screen Run Time OBA Overload Icon Input Overload Icon Measurement Power Indicator Name Measurement LD 0 00 50 7 in E Status LxT_Data Section Indicator Scroll Bar Live Page Stability LaAeq 1s Indicator Las 86 2 dB LZpeak 96 9 dB Started 2006 Apr 23 14 36 04 Center Right Softkeys FIGURE 3 1 Data Display Screen LxT Manual Overview 3 1 Display Sections and Icons Screens Tabs Page Scroll Bar and Section Indic
152. g Functions From the Control Panel The Left and Right Softkeys and the 7 KO O and O keys allow selection of the desired function To activate the desired function press the key Pressing the Center Softkey labeled Close will return to the Data View Keypad LxT Manual LEFT and RIGHT Keys UP and DOWN Keys ENTER Key RUN PAUSE Key STOP STORE Key Note Pressing the E RUN PAUSE key when the unit is in STOP mode will continue the previous run LxT Manual The O and O keys are used for moving horizontally on a screen This includes moving the highlight from one property to the next The C and keys are used for moving vertically on a screen This includes moving the highlight from one property to the next and to move to a previous or next data page section These keys are also used for character entry by scrolling through a list of characters in a text box The key is typically used for completing an action or accepting a value The im RUN PAUSE key will initiate a run If a measurement is running this key will pause the run It will not end the run the P STOP STORE key is used for that Pressing the Ez RUN PAUSE key when the unit is PAUSED will continue the run This key is only active on a Data View screen The Ez STOP STORE key will end a run Pressing the key a second time will store the data in a file This key is only active on a Data View screen Keypad 3 11 Screens 3 12 T
153. g the Month LxT Manual The time and date for the LxT may be adjusted on the time page O Syne Date Time with PC Close FIGURE 11 3 Time Page Using the 7 CA and O keys highlight the data field of the numerical parameter to modify Press the key to highlight the 1st character position in the date year or time field The CT ED 6 and O eys are used to modify the parameter Press the key when modifications are complete When the Month box is highlighted pressing the key will drop down a list of months See FIGURE 11 4 Month List Time 11 3 Sync Data Time with PC 11 4 5 0 00 00 0 0 System Properties etm Time TEST ACHEN lith PC FIGURE 11 4 Month List Use the and keys to highlight the desired month Press the Gores key to accept the selection and exit the field Selecting the Sync Date Time with PC check box enables the LxT time to be set to the PC time when the unit is connected to the LxT Utility software This function is enabled if there is an X in the check box To modify the state of the os box move the highlight to the check box and press as key The state of the check box will change Time LxT Manual Power Auto Off Time LxT Manual gt 0 00 00 0 0 System Properties eM Power DEGO Auto Off Time Power Save Time Backlight Time Always On e Backlight Bright v Display Contrast Battery Type Alkaline v Close FIGURE 11 5 Power Page There
154. ge embedded in the electret material so no internal source is needed Microphone Uses The frequency response of microphones can be adjusted to be used in specific applications Among those used are Frontal incidence Free Field The microphone has been adjusted to have an essentially flat frequency response when in a space relatively free of reflections and when pointed at the source of the sound Random incidence The microphone has been adjusted to have an essentially flat frequency response for sound waves impinging on the microphone from all directions Pressure The microphone has not been adjusted to have an essentially flat frequency response for sound waves impinging on the microphone from all directions Glossary LxT Manual LxT Manual What a microphone measures 4 microphone detects more than just sound The motion of a microphone diaphragm is in response to a force acting on it The force can be caused by a number of sources only one of which are we interested sound Non sound forces are 1 direct physical contact such as that with a finger or a raindrop 2 those caused by the movement of air over the diaphragm such as environmental wind or blowing 3 those caused by vibration of the microphone housing and 4 those caused by strong electrostatic fields Rules 1 Do not permit any solid or liquid to touch the microphone diaphragm Keep a protective grid over the diaphragm 2 Do not blow on a microphone and
155. ght delay from pressing the button until a start up screen is displayed There are three methods to turn off the LxT e Method 1 Press the ON OFF key to bring the Power Control Page into view Press the Left Softkey labeled Off to turn off the LxT e Method 2 Press and hold the ON OFF key e Method 3 Press the L ON OFF key twice Keypad LxT Manual Power Control Page Note that the Backlight and Display Contrast can also be adjusted from the Power Page as described in the section Power on page 11 5 LxT Manual If the LxT is ON pressing the ON OFF key will bring up the Power Control screen 5 0 00 12 1 4 il Power Control Battery Estimated Run Time Hr Battery Voltage 0 0 USB Powered 4 7 Backlight Bright 4 Display Contrast ES T internal 95 8 F 35 4 C Off Close Setup FIGURE 3 2 Power Control View Located on the first section of this screen is the Estimated Battery Run Time calculated using the voltage of the installed batteries Battery Voltage and the USB Power voltage In the next section of this display Backlight Mode and Display Contrast are adjusted using the O O CZ and US keys There are 3 choices for Backlight Mode Off Dim and Bright which are adjusted using the O and O keys The Display Contrast has a range of 9 to 9 which is adjusted using the 7 and E keys The last section displays the LxT temperature that is used to automatically adjust
156. ghted sound level is less than Ly L is the threshold sound level specified by the manufacturer Lc is the criterion sound level specified by the manufacturer Q is the exchange rate in dB and q the parameter that determines the exchange rate where q 10 for a 3dB exchange rate q 13 29 4 log 2 for a 4dB exchange rate q 16 61 S5 log 2 for a 5dB exchange rate q 20 6 log 2 for a 6dB exchange rate The factor of 100 in the equation produces a result that is a percentage Dose is obtained from the accumulations made for TWA and SEL using the formula where La is the current SPL at sample s for measurements that include a threshold Lys is set to x if Lis is less than the Threshold Level Ly s T 2l rt KS k log T 115200 log 100 DOSE 10 Integrated Level Calculations Model 831 Manual Model 831 Manual k is the exchange rate constant See the explanation for q on the previous page n is the total number of samples taken in the measurement The sample rate is 32 samples per second T is the criterion sound duration as set by the LxT s Criterion Time Hours setting which by default is set to 8 hours L is the criterion sound level as set by the LxT s Overall Criterion or Current Criterion settings Addition of the term log 100 was used to implement the 100 multiplier of the ANSI equation that creates the percentage Subtracting the log of the Cr
157. gt 10 V m The Larson Davis model LxT1 was not measured for field strengths greater than 10 V m n Radio Frequency Emission The mode of operation of the LxT1 that produces the greatest radio frequency emission levels was with the LxT1 set to run and with an LxT EXC010 OO microphone extension cable used to connect the PRMLxT 1 to the LxT1 Adding the USB cable did not emit more radio frequencies levels o AC Power and Radio Frequency Susceptibility The mode of operation of the LxT1 that produced the greatest measurement susceptibility to A C power frequency and radio frequency fields was with the LxT1 set to run USB cable attached and with an LxT EXC010 10 microphone extension cable between the PRMLxT1 and the LxT1 LxT2 Section 9 2 4 a Calibrator The calibrator to be used with the LxT2 is the Larson Davis Model CAL150 b Calibrator Frequency The calibration check frequency is 1000 Hz c Calibration Procedure For calibration refer to the chapter Calibration on page 10 1 LxT Manual LxT2 B 13 d Frequency Response Table 1 Larson Davis LxT2 with PRMLxT2 and typical 7052S Microphone average frequency responses and corrections Required by IEC 61672 1 Sections 5 2 4 5 2 5 5 2 6 and 9 2 4 d 0 Free Field expanded Wind Screen Corrections with uncertainty 0 Free Field 0 Free Field Effect of on LxT2 Wind Screen of Corrections Frequency Response Corrections Wind Screen 0 Free Field on LxT2 95 H
158. he batteries and terminals Inserting Alkaline Batteries LxT Manual FIGURE 2 7 Insert Batteries After the batteries are installed insert the two tabs on the bottom edge of the battery door into the mating slots in the case Close the battery door allowing the clip to snap in place on the case Install the screw that was removed at the beginning of the procedure Hardware Power Switch DO NOT use the hardware power switch to turn the LxT OFF This may cause data to be lost Press the L lte then the Off soft key to turn the LxT off LxT Manual The Hardware Power Switch on the bottom of the LxT as shown in FIGURE 1 4 The LxT Bottom View on page 1 14 and FIGURE 15 3 LxT Bottom Panel on page 15 5 disconnects the batteries from the LxT hardware including the real time clock This prevents battery drain when the LxT is not in use for an extended period of time 2 weeks If the Hardware Power Switch is in the O position the batteries are disconnected After installing batteries be sure to move the switch to the position This applies power to all of the LxT hardware The Hardware Power Switch should not be used to turn the LxT ON and OFF If the Hardware Power Switch is used to turn the LxT off data may be lost See also Switching On the LxT on page 3 1 Hardware Power Switch 2 7 Using USB Power The LxT cannot be operated under USB power if the internal batteries are discharged flat
159. he unit of A weighted sound exposure is pascal squared seconds if A weighted sound pressure is in pascals and running time is in seconds However it is sometimes Integrated Level Calculations Model 831 Manual Note that the LxT displays Sound Exposure Level as Lyg where X is the frequency weighting X A C or Z expressed in pascal squared hours for measurements of noise exposure in the workplace Sound Exposure Level The A weighted sound exposure level Lap is related to a corresponding measurement of time average A weighted sound level Lay or Lagegr by t2 Lac 101g p3 e dt Vlait paB 1ole e WAT Lar 101g T 7 WB tl where E is the A weighted sound exposure in pascal squared seconds Ej is the reference sound exposure of 20 Pa x 1s 400 x 10 Pa s TO 1s T t ty the time interval for measurement in seconds for sound exposure level and time average sound level Model 831 Manual Integrated Level Calculations C 9 Community Noise Descriptors Lon The day night level Lpy defined by the following formula 0700 2200 2400 1 L 10 10 L 10 L 10 10 Lan 10Log p 24 gt 10 10 10 0000 0700 2200 LDEN The day evening night level Lpgn is defined by the following formula 1 Lday Levening 5 Lnight 10 Digs od Alz 0 44 19 8 10 1 In the default form the day has eight hours the evening has four hours and the night has eight hours as can be seen in the equation The d
160. here are four different screens available on the LxT e Data Display Screen used to display measured data Measurement Properties Screen used to set the parameters for a measurement e Tools Screen used to set non measurement related parameters and to implement calibration e Power Control Screen used to check battery power control the contrast and backlight of the display and other features The diagram shown in FIGURE 3 5 Main View Block Diagram illustrates the manner in which the user can move between these four screens Data Display Screen A l Measurement Tools Screen Properties Screen Power Control __ Screen FIGURE 3 5 Main View Block Diagram Screens LxT Manual Data Display Screen Measurement Properties Screen Tools Screen Power Control Screen LxT Manual When the ON OFF key is pressed to switch ON the LxT the Data Display Screen appears From the Data Display Screen pressing the Center Softkey labeled Menu will bring up the Measurement Properties Screen When in the Measurement Properties Screen pressing the Center Softkey now labeled Close will bring back the Data Display Screen The Tools Screen is accessed by pressing the A TOOLS key at the lower right of the LxT front panel To exit from the Tools Screen and return to the Data Display Screen press the Cent
161. hone Larson Davis provides the WS001 windscreen a 3 1 2 diameter ball made of open cell foam which can be placed over the microphone and preamplifier as shown below FIGURE 7 4 Position of Windscreen To install the windscreen hold the meter in one hand and the windscreen in the other Insert the microphone preamplifier assembly into the opening in the windscreen as shown below Positioning the LxT LxT Manual The position of the vertical scroll bar on the right side of the display indicates the page being displayed relative to the available pages first page at the top last page at the bottom LxT Manual and slide the windscreen completely down over the preamplifier FIGURE 7 5 Placement of Windscreen Prior to beginning the measurement select the Live View You can now see a live display of the instantaneously measured data The data available for display from the Live View is distributed over three pages four or five pages with the optional OBA feature Use the CI and CH keys to change pages Take a minute or so to examine these different displays before continuing with this example Use the softkeys to select the Overall View Note that the measurement and display of data has not yet begun and that the measurement run time displayed at the very top of the screen indicates 00 00 00 0 Positioning the LxT 7 7 Performing the Measurement Starting the Measurement The LxT uses a single range for sound
162. ht the Time data field and press the key This will produce a cursor which can be moved left and right to Dosimeter 1 and 2 Pages LxT Manual Stop When Stable Mode LxT Manual different digit positions in the data field using the and O keys as shown in Figure 4 18 Time 10 00 20 hh mm ss FIGURE 4 18 Entering Time in Timed Stop Run Mode At any digit position use the LJ and keys to adjust the value over the range 0 to 9 When the desired value of time has been entered press the key to conclude the process 0 01 35 1 Time His Run Mode fStop When Stable Delta dB Time 00 00 20 hh mm ss FIGURE 4 19 Stop When Stable Run Mode The run mode is indicated as Stop When Stable Data fields are provided to define Delta and Time Entering Delta Level The Delta level is the maximum one minute change in overall average level ie Laeg allowed for the measurement to be considered stable Entering Time The Time is the duration that the measurement must run before the measurement can stop If the time were set to 0 the measurement would run until the stability condition was met Dosimeter 1 and 2 Pages 4 19 If a duration is set the measurement would run for the duration specified and then continue until the stability condition was met For each use the C7 and keys to highlight the desired data field and press the Da key Use the and O keys to position the cursor and the 3 and keys t
163. ications A 21 LxT With 7052 Free Field Microphone and PRMLxT2 Preamplifier LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 4 0 dB 2 0 dB 0 0 dB E dB Mic 120 FIGURE A 10 LxT with 7052 Microphone 0 60 and 120 degree A 22 Technical Specifications LxT Manual LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 4 0 Mic 135 FIGURE A 11 LxT with 7052 Microphone 15 75 and 135 degrees LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 4 0 dB 2 0 dB 0 0 dB 2 0 dB 4 0 dB 6 0 dB 8 0 dB 10 dB 0 dB 200 Hz Mic 30 Mic 90 FIGURE A 12 LxT with 7052 Microphone 30 90 and 150 degrees LxT Manual Technical Spec
164. ifications A 23 A 24 LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 4 0 1K Hz Mic 105 Technical Specifications FIGURE A 13 LxT with 7052 Microphone 45 105 and 165 degrees LxT Manual Directional Characteristics LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 0 4 0 dB Mic 1000 00 Hz Mic 1995 26 Hz Mic 3981 07 Hz Mic 7943 28 Hz FIGURE A 14 LxT with 7052 Microphone 1000 00 Hz 1995 26 Hz 3981 07 and 7943 28 Hz LxT Manual Technical Specifications A 25 LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189 Serial Number 2440346 02 4 0 dB Mic 1258 93 Hz Mic 2511 89 Hz Mic 5011 87 Hz Mic 10000 00 Hz FIGURE A 15 LxT with 7052 Microphone 1258 93 Hz 2511 89 Hz 5011 87 Hz and 10000 00 Hz A 26 Technical Specifications LxT Manual LD Model LxT SLM Serial Normalized to 251 19Hz 0 Tested 12 27 04 15 58 03 by Note with 7052S Mic and PRMLxT2 Preamp Reference Mic B amp K Model 4189
165. ime on page A 6 LxT Manual Sections 5 6 7 and 9 except 9 3 Section LxT Manual Comments b Power Indicator on page 3 2 c Power Supply Specifications on page A 5 d The LxT is not intended to be powered by a public source of AC power 9 2 4 Adjustments to Indicated Levels a Recommended Calibrator on page 13 3 b Recommended Calibrator on page 13 3 c Calibrating The LxT on page 13 7 d See d Frequency Response and Corrections on page B 9 9 2 5 Operating the Sound Level Meter a General Specifications on page A 4 b Positioning the LxT on page 7 5 c The LxT measures sound level using a single range d Low Level Sound Fields on page 7 16 e Start up Period on page 7 2 f Integration on page 4 6 g Control Page on page 4 16 and Time on page 11 3 h Timed Stop Mode on page 6 4 i RESET Key on page 3 8 and Maximum Minimum and Peak Sound Levels on page 5 9 j Overload Indication on page 7 11 and Maximum Minimum and Peak Sound Levels on page 5 9 k Measurement Range on page 7 11 Triggers Page on page 4 20 Sections 5 6 7 and 9 except 9 3 LxT Manual Section LxT Manual Comments m Software on page 1 12 n Connectors and Interfaces on page 16 5 o h Inherent Noise on page B 12 p AC DC Output Specifications on page A 5 and Jack Function
166. ion Log Page LxT Manual Each measurement segment from Run to Stop is numbered as is each voice message Using the 7 and keys the user may scroll the list and expand each item In the upper right corner of the expanded item the number indicates which item is being viewed out of how many total items are in the list Adjust Graph Scale LxT Manual The graphic display of sound pressure level versus time and frequency spectra 1 1 and 1 3 octave uses default settings of 50 dB for the baseline and a range of 70 dB making the top of the graph 120 dB To change any one of these graphs press the Menu softkey to obtain the display shown in FIGURE 5 20 Settings Mark Sound Type Adjust Graph 2006 Jun 06 09 39 30 d Enter gt By 1 3 Frequency J FIGURE 5 20 Graph Menu Display Adjust Graph Scale 5 23 5 24 Use the CO key to highlight Adjust Graph and press the key to obtain the Adjust Graph menu shown in FIGURE 5 21 FIGURE 5 21 Adjust Graph Menu Use the 6 and O keys to change the baseline level and the and gt keys to adjust the range between the baseline and the top of the display Press the key to implement the change Adjust Graph Scale LxT Manual CHAPTER Run Control The LxT provides a number of run modes to control the time duration of a measurement These are all described in detail in this chapter Run Control Setup The Run Control is setup from the Control Page of the Measu
167. iption E Ee heh ic AO 10 2 Test Run Time ccccccccccccssscesceceseccsseeesceesecesssceseecsseeessecesecseseaecesesesaeceseeceeeeseseseecnas 10 2 Data Labels O e ect 5 1 LxT Manual a 3 Data VIEW SCrE Nii o len 10 4 Date Format seal dk ates wie Ble eee hen te etnies 11 10 Day Evening Night Level C 10 Day Night eebe nuit edel Eeler C 10 aleet EE 11 12 Dec bezeien earen eessen DA Decimal Symbols eeh Dese ee debe ead nie enn eae 11 10 Declaration Of Conformity 0 0 ccc cccecesecseeeceeeseseeseesecseesessessecaeeeesaeessseeeeaes A 2 Delete Alt Files ij secs eee ees eo oe eo ae a as 10 5 Delete Ell es ternet loto 10 5 Department of Defense TOV A entgeet ee SERA E dd teste Ee eet A D 7 RE OT D 7 Device Page toas semithin EEN 11 2 Display Backlight EE 3 12 Display Contrast 2 00 28 cece ote ee ease te Ree oe i 3 7 11 7 Display Customization 00 cece cece ceeceseceeeecseesseseeseesecseeseesesaecaeeeesaesaeseeesaes 11 14 Display Sections I CONS Stee 3 2 Measurement Nadia he Kh Bite hein EE Ae 3 3 Mea Ureta 3 4 Para ad oo a nt a o o id oe dh 3 2 NS Eed ZE eu ee EES 3 2 Run iman ee 3 3 Scroll Ba Ee 3 2 Section AMGIC E 3 2 Stability IndicatO au sec ced ENEE o ENT 3 3 EE 3 2 Displays Selecting Displays to Appen 11 14 Displays Page EE EE 11 14 Duration Meas rement sisie a it gesend D 12 E Eight Hour TWA e E et intl es atest D 8 Edda Tes E 3 11 Enter Keys soc Cie is tea oe A A edd 3 11 Equivalent
168. isplay Screen Live Page The 22 STOP STORE key will produce a steady red light to indicate that the LxT is in the stopped state with no data yet measured LxT Manual Switching On the LxT 7 3 Views Softkeys 7 4 In this screen there are three tabs labeled Live Overall and Session Log each of which is associated with a page Because the Live Tab is selected the Live Page is seen in FIGURE 7 2 The Left and Right Softkeys defined below are used to select these tab pages There are three buttons beneath the display aligned with the left arrow Menu and right arrow keys as shown in FIGURE 7 3 Softkeys These buttons are called softkeys because pressing any one will invoke the action associated with the text or symbol directly above it on the screen In this instance pressing the Left or Right Softkey will display the tab page to the left or right respectively of the tab page presently displayed The Center Softkey will open a menu associated with this screen These are context sensitive meaning that the text or symbol above each Softkey and the associated action can change depending upon the page appearing at that time See Chapter 3 Softkeys on page 3 5 Switching On the LxT LxT Manual LxT Setup Set the measurement parameters of the LxT as described in Chapter 4 Basic Measurement Setup on page 4 1 Calibrating the LxT The LxT must be calibrated using a sound level calibrator
169. iterion Time was used to implement the division of Criterion Time of the ANSI equation Projected Dose in the analyzer is obtained with an equation similar to that of Dose except that the actual duration time of the measurement is used rather than a Criterion Time as thus MO e k Le log Y 10 log n log 100 PROJDOSE 10 where the log n is the actual time factor n being the total number of samples taken Integrated Level Calculations C 7 DOSE E 0 08 03 9 ll 831_Data 4j Overall EES Ah 49 7 dB 67 4 dB 62 6 dB Projected DOSE The currently selected Frequency Weighting A and Detector Response Slow for SPL 0 03 2 1 76 4 Slow The currently selected Exchange Rate 3 dB 80 0 dB 8 0 h 85 0 dB Criterion Time and Level Run Time 0 08 03 9 Elapsed measurement time shown as h mm ss s FIGURE C 3 DOSE and Projected DOSE Sound Exposure Calculations Note that the LxT displays Sound Exposure as Ey where X is the fre quency weighting X A C or Z See FIGURE C 2 Sound Exposure Level and Sound Exposure C 8 Sound exposure and sound exposure level are calculated as specified in IEC 61672 1 Sound Exposure The A weighted sound exposure E of a specified event is represented by 12 Es f Pat where P t is the square of the A weighted instantaneous sound pressure during an integration time starting at t and ending at tp T
170. l See Average Sound Level See Noise Dose The part of a sound level meter that converts the actual fluctuating sound or vibration signal from the microphone to one that indicates its amplitude It first squares the signal then averages it in accordance with the time weighting Glossary D 7 Eight Hour Time Weighted Average Sound Level L twais Energy Equivalent Sound Level eq Exchange Rate Q Exchange Rate Factor q Exposure Factor k Far Field characteristic and then takes the square root This results in an amplitude described as rms root mean square It is the constant sound level that would expose a person to the same Noise Dose as the actual unsteady sound levels The equation for it is D Lrwa s Let ghog io NOTE This definition applies only for a Criterion Duration of 8 hours Standard ANSI S12 19 The level of a constant sound over a specific time period that has the same sound energy as the actual unsteady sound over the same period ia pp oat 2 L ae 10Lo0g 19 Pot e where p is the sound pressure and the Measurement Duration specific time period T T T See Sound Exposure Level It is defined in ANSI S1 25 as the change in sound level corresponding to a doubling or halving of the duration of a sound level while a constant percentage of criterion exposure is maintained The rate and the factors are given in the table below Standard ANSI S12 19
171. l Tools Screen 3 17 Selection of an item is done by highlighting the icon representing the desired function and pressing the D key To highlight a particular icon the Left and Right Softkeys and the O CZ and US keys are used as indicated by the arrows in FIGURE 3 9 Highlighting a Tools Icon Data Calibrate CJ and CH Keys or Explorer Left and Right Softkeys Ee H System Voice Properties Recorder ck and O Keys FIGURE 3 9 Highlighting a Tools Icon Data Explorer For a detailed description of the The Data Explorer is used to examine data which had been Data Explorer see Chapter 10 Data stored following previous measurements It is also used to Explorer on page 10 1 manage stored measurements such as rename or delete files 3 18 Tools Screen LxT Manual System Properties For a detailed description of the System Properties Pages see Chapter 11 System Properties on page 11 1 System Property Pages are used for general instrument bookkeeping Functions such as setting the instrument date and time display contrast adjustment date format etc are located here These are single section pages There are four System Property Pages e Device instrument identification is entered here e Time the date and time are set on this page e Power controls that affect power consumption are located here Preferences regional characteristics are configured here e Displays set displays to appear or be
172. lowing table references sections and tables in this manual where information called for in specific sections of IEC61672 1 can be found In certain instances the requested information is not applicable as noted in the Comments column Further information called for in section 9 3 for testing as appropriate for a sound level meter can be found in Section 9 3 on page B 10 Section LxT Manual Comments 5 1 4 LxT Components on page 1 13 5 1 6 Standard Accessories on page 1 9 and Optional Accessories on page 1 10 5 1 7 Connecting the Microphone and Preampli fier on page 2 3 and Connecting the Preamplifier to the LxT on page 2 4 5 1 8 Computer software is not an integral part of the LxT 5 1 10 LxT Main Characteristics on page A 3 5 1 12 The Model LxT measures sound level using a single range 5 1 13 General Specifications on page A 4 5 1 14 RESET Key on page 3 8 and Maximum Minimum and Peak Sound Levels on page 5 9 LxT Manual LxT Manual B 1 Section LxT Manual Comments 5 1 15 AC DC Output Specifications on page A 5 and g Electrical Insert Signals on page B 11 5 1 16 i Highest Sound Pressure Level on page B 11 5 1 17 The Model LxT is a single chan nel instrument 5 1 18 Start up Period on page 7 2 5 2 1 Calibrator on page 13 3 5 2 3 Calibrating The LxT on page 13 7 5 2 4 9 2 4 d Frequency R
173. me the display will change to a 1 3 octave display and the text message will change to read Enter gt By Time Time History Display LxT Manual LxT Manual LxT_ Data ETA Time History gt 1 00kHz Leg 40 6 dB max 43 6 dB min 39 0 dB d 2 21 2006 Jun 08 15 28 48 Enter gt By Time FIGURE 9 14 Enter gt By Time To Display Time History From this display 1 3 octave data are displayed and the 6 and keys can be used to scroll forwards or backwards in time respectively As indicated by the text message press the Enter key again to return to a time history display as shown in FIGURE 9 12 Time History Display 9 17 Markers Markers Setup 9 18 Markers are used to annotate portions of the time history especially for the purpose of identifying sound sources as they become dominant in the measurement The LxT offers ten separate user definable markers Markers are setup using the Markers tab page of the Measurement Setup View as shown in Figure 9 15 view 1 5 06 10 ruck Automobile Motorcycle Aircraft xclude FIGURE 9 15 Markers Setup Window Markers 1 5 There are five markers with names predefined for convenience shown in this figure Any of these names can be changed by the user To view markers 6 10 use the O key to highlight the 6 10 text line and radio button and Markers LxT Manual Naming a Marker The process of naming markers is simplified by
174. me History Display To return to the time history display press the Enter key as indicated in the test message near the bottom of the display shown in FIGURE 9 11 9 14 Time History Display LxT Manual 1 1 and 1 3 Octave Spectra When both 1 1 and 1 3 octave spectra are being logged the time history display will begin by displaying the text message Enter gt By 1 1 Octave as shown in FIGURE 9 12 LD 0 00 18 7 i LxT_Data W SSEN Time History d 2 21 4 2006 Jun 08 15 28 48 Text Message Enter gt By 1 1 Frequency WJ FIGURE 9 12 Enter gt By 1 1 Frequency To Display 1 1 Octave Spectrum From this display the single parameter time history data are shown and the 3 and keys can be used to scroll forwards or backwards in time respectively LxT Manual Time History Display 9 15 By pressing the key the display will change to a 1 1 octave display and the text message will change to read Enter By 1 3 Octave as shown in FIGURE 9 11 60 00 18 7 i LxT_Data DH A Time History al e Hitt E gan gt 1 00kHz Leq 48 6 dB 53 2 dB 47 8 dB d 2 21 2006 Jun 08 15 28 48 Text Message Enter gt By 1 3 Frequency H FIGURE 9 13 Enter gt By 1 3 Frequency To Display 1 3 Octave Spectrum From this display 1 1 octave data are displayed and the 6 and keys can be used to scroll forwards or backwards in time respectively By pressing the key one more ti
175. me Weighting Integration EN Y Dosimeter 1 and 2 Pages Y Predefined Setups 0 Parameters Individually Defined L Name Field Parameter Fields L Exchange Rate Y Threshold and Criterion Y Auto Calculate FIGURE 1 2 Bookmarks Expanded E E E Thumbnails 7 2 E o o 7 d 2 Z i KO Left click on any text field Chapter name Appendix name Table of Contents Index or any sub heading and the page displayed on the right will jump to the page associated with that text field To return to the page which was displayed previous to clicking on a bookmark text line click the View Menu in the menu bar Click the Goto and then Previous View on the pop up menus LxT Manual Special Features of the Electronic Version 1 5 Links Click a Link to Display a Page Return to Previous View Cross References Click Cross Reference Return To Previous View 1 6 The Table of Contents and the Index have a page number associated with each item For the Table of Contents left click on the text line and that page will be displayed For the Index left click on the page number itself to display the page associated with that entry To return to the page which was displayed previous to clicking on an item in the Table of Contents or a page number in the Index click the View Menu in the menu bar Click the Go to and then Previous View on the pop
176. ment Property Screens 4 22 Chapter5 Basic Data Display Date Label uniones 5 1 Tabbed Page Structure ccccoccccccnnncccnnncns 5 1 Eve e e e otra 5 2 ii iv 1 1 Octave Band Analyzer Optional 5 4 CUTSOT isc siii o 5 5 1 3 Octave Band Analyzer Optional 5 5 TRIG OSTA Gs E 5 6 Time Battery Voltage and Memory 5 7 Overal Fage iras raid 5 8 Eeer Ae 5 8 Maximum Minimum and Peak Sound Levels 5 9 1 1 Octave Band Analyzer Optional 5 11 AAA A E E E asa che iakks 5 12 A E EE A A id iaa 5 12 EMAK O NE 5 12 1 3 Octave Band Analyzer Optional 5 13 Dosimeter 1 and 2 5 14 Sound Exposure E 5 15 e EE 5 16 En Ge 5 17 A a e gl ERE 5 18 8 ele EE 5 19 Number of Measurements occccccccnoocccnnccncnicos 5 20 Equivalent Levels ANN 5 21 Session Log Page ERR 5 22 Adjust Graph Scale oooccooccccccnocccccnnccnnconos 5 23 Chapter6 Run Control Run Control Getup Nk 6 1 RUN lee E 6 3 Manual Timed Stop Stop When Stable or Contmuous 6 3 Single Block Time or Daily Time 0 0 0 cc ececsseeceeeceeceeeeeeeeeeeeaeeeees 6 3 Manual Stop Mode ooccccccccocccccccccnnocccnnnnnnnnnncnnos 6 3 Timed Stop Mode cccccssecceeeeeeesseseeeeeeneees 6 4 Entering Run Le tia asista 6 4 Stop When Stable Mode nnnnnnnnnenanneeenneeeennn 6 5 Entering Delta Level cin iii tica 6 5 Entering Tine ata 6 5 Continuous Run Mode oooocccccccccnoo
177. meters for the measurement of sound exposure and noise dose Ln used to define the parameters for the measurement of Ln statistics e OBA optional used to setup the real time octave band frequency analysis e Control use to setup the mode of measurement timing e Time History optional Permits the automatic logging of up to xxx parameters as a function of time e Triggers used to setup the triggers which define noise exceedance events e Markers optional Use in conjunction with time history measurements this feature permits the user to annotate portions of a time history record to identify noise sources or make other notes Screens LxT Manual Softkey Selection of Setup Pages lt p General Control Time History Triggers Markers Optional Feature FIGURE 3 7 Measurement Properties Screen Changing Setup Pages As indicated in the diagram to switch between setup pages use the Left and Right Softkeys Since each page has only one section vertical scrolling is not required Tools Screen For a detailed description of the The Tools Screen uses icons to represent the different Tools Screen see Control Panel functions available as shown in FIGURE 3 8 Tools System Properties on page 11 1 Screen Control Panel y Data Calibrate Explorer Voice Recorder E FIGURE 3 8 Tools Screen LxT Manua
178. n FIGURE 2 4 Push Button to Release Preamplifier If the LxT is switched ON when the preamplifier is disconnected the Preamp Disconnected message box will appear for several seconds lt gt 0 00 00 0 Session Log TiQ ENTERAN css 110 F Preamp Disconnected FIGURE 2 5 Disconnect The Preamplifier Press the key to clear the message box LxT Manual Disconnecting the Preamplifier from the LxT 2 5 Inserting Alkaline Batteries Note There are 2 tabs on the bottom of the battery door that engage the case of the LxT The LxT is designed for use in areas requiring Intrinsic Safety approval as well as use in safe atmospheres By the standards it is required that access to the battery compartment be secured to deter opening in a hazardous atmosphere and batteries cannot be changed in a hazardous atmosphere A hex screw is provided to secure the battery door in these uses Extra screws were provided when the unit was shipped The battery compartment of the LxT is located on the back of the unit There is a clip on the battery door and a hex screw holding the door in place To remove the battery door first remove the screw if installed Then pull the clip towards the battery door while lifting The battery door will pivot away from the unit 2 6 pa an oF 33 22 EE Ge GLI AD ONNOS FIGURE 2 6 Battery Door Insert 4 fresh AA alkaline batteries as shown in FIGURE 2 7 Ensure correct alignment of t
179. n Switchcraft female 100 feet long 18 pF equivalent Y Microphone with BNC Connector input ADP008 Adapter for 1 microphones ADP040 Microphone Signal Tee ADP043 Adapter for 1 4 microphones ADP068 Preamplifier holder for Y preamplifiers on microphone stand Table A 23 Optional Accessories In the interest of constant product improvement specifications are subject to change without notice Larson Davis provides a complete line of acoustic measurement tools including dosimeters sound level meters real time analyzers preamps calibrators and microphones A 44 Technical Specifications LxT Manual O Preamplifier Model PRMLxT2 Serial Number 0182 Larson Davis Certificate of Electrical Conformance Frequency response of this model PRMLxT2 preamplifier was tested at a level of 5 356 Vrms with 18pF microphone capacitance and driving a short cable Output level at 1kHz is 1 0039 Vrms 0 034 dBV uncertainty 0 035 dB Output is 3 454 V DC uncertainty 0 001 Results are displayed relative to the level at 1kHz 0 5 50 100 200 501 1000 1995 5012 10000 19953 50000 100000 Frequency Hz Freq Hz Measured dB Uncert dB Tolerance dB Freq Hz Measured dB Uncert dB Tolerance dB 16 0 06 058 0 09 0 21 794 33 00 016 0 10 0 10 98 0 04 058 0 10 0 18 1000 00 00 016 0 10 0
180. n time and the Criterion Level The remainder of the display shows the parameters used for the measurement Frequency Weighting Exchange Rate Threshold and Criterion time and level Sound Exposure 0 00 33 7 i LxT_Data Sound Exposure Level LASE 82 0 dB Sound Exposure Eas 17 76u Pa2h Eass 15 18m Pa2h Eas40 75 90m Pa2h EAS 63 94m Pa s EAS8 54 646 Pa s EAS40 273 23 Pa s Run Time 0 00 33 7 FIGURE 5 12 Overall Page Section 7 Section 7 shows the Sound Exposure metrics in this instance for A weighted Slow L sg is the sound exposure level previously known as SEL The Sound Exposure metrics indicate the actual and extrapolated 8 and 40 hours exposure accumulated in terms of hours and seconds These are discussed in Sound Exposure SE on page D 17 and Sound Exposure Level SEL LE on page D 17 LxT Manual Overall Page 5 15 SEA SEA Frequency Weighting Z Start Time 2006 Jun 05 17 13 29 End Time 2006 Jun 05 17 15 00 Run Time 0 00 33 7 FIGURE 5 13 SEA Display Section 8 SEA is an integration of 1 second peaks that exceeded 120 dB Both the SEA value and the frequency weighting used for the measurement are displayed 5 16 Overall Page LxT Manual Ln Percentiles Ln Percentiles LASmax 67 1 dB LASS 66 7 dB LAS10 65 9 dB LAS33 3 56 4 dB LAs50 54 0 dB LAS66 6 49 3 dB LAs90 45 3 dB LASmin 32 2 dB Run Time 0 00 17 3 FIGURE 5 14 Overall Page Section 9
181. nable Time Histor FIGURE 9 1 Time History Setup Menu Press key to enable the Time History functionality and to place a check in the Enable Time History check box This will add additional items to the Time History setup menu as shown in FIGURE 9 2 Time History Setup 9 3 ER 0 00 00 0 ZS D Settings AA Time History Enable Time Histor ime History Options C Lmax Lpeak L Lmin L LCSeq L Seq O LAFTMS O Ltwat Close FIGURE 9 2 Time History Setup Menu Enabled Time History Setup LxT Manual Set Time History Period As you scroll downwards when the highlight reaches the bottom of the window the list will scroll upwards to reveal additional values LxT Manual To set the Time History Period use the C key to highlight the Period data field and press the Come key to list all the available values of time as shown partially in Figure 9 3 FIGURE 9 3 Time History Period Menu The following values are available for selection as time increment for the Time History Seconds 1 2 5 10 15 20 30 Minutes 1 2 5 10 15 20 30 Hours 1 24 Time History Setup 9 5 Use the CH and CY keys to highlight the desired increment of time and press the key to make the selection Select Time History Parameters The parameters available for selection are described in Parameters Logged on page 9 1 Exiting Time History Options 9 6 The Time History Options Menu is used to select on
182. naren a EE 12 3 Eo Kk WLAU O OE id Ae EEE Eege 12 3 li ix Lock w Manual Store cccccccccesssccessecessececesecesseceecssecessseeesseess 12 3 Fully Locked ita telar 12 3 Unlock ee EE 12 4 Allow Cal When Locke 12 5 Full LockS donas ir s 12 6 Locked With Auto Store oocoocococcccnccciccnccno 12 9 SS AA A A A 12 11 Locked With Manual Store 12 12 LEES POE eene RT 12 13 Calibration When The LxT Is Locked 12 14 Chapter 13 Calibration Control Panel Calibrate 13 1 Exiting from the Calibration Function 13 2 LS ee 13 2 Elte 13 3 Recommended Calibrator ocooooccnccnonanncninnnnannaninnnnannanococannnonicnns 13 3 Calibrating the LxT1 and 377B02 microphone cesses 13 3 Calibrating the LxT2 and 7052 meropbone 13 4 Adding a Calibrator oooconiconcciococonconconncononnconn cnn E con cron pE 13 5 Calibrating The LXT cccccccssssesseeeeeeenesseees 13 7 HISTON EE 13 9 CEITICAUOM sic sete Bede ede eben 13 10 Chapter 14 About Control Panel About 14 1 ele 8 EES 14 2 Ee E re EE 14 3 EE eg 14 4 REENEN 14 5 Ol EEN 14 6 Chapter 15 System Utilities Control Panel System Utilities 15 1 File SYSIOM EE 15 2 Check File System AAA 15 3 FROM EE 15 3 Format 8 Restore Defaults o cooooo 15 3 Chapter 16 LxT Hardware Components c ooccccnccncnncnnonccnnoncnnonanononannnnanons 16 1 Microphone and Microphone Pr
183. ning the measurement FIGURE 9 5 Time History Display First Point Keypress Beginning Measurement Note that the graph scaling can be The first display labeled Run represents the keypress modified as described in section initiating the measurement with the corresponding data and Adjust Graph Scale on page 5 23 time There will be be no measured data associated with this sample point LxT Manual Time History Display 9 7 Data Display at Cursor Position Time History history interval Graph Leq x where x is the time Press the O key once to display data measured during the first time interval as shown in FIGURE 9 6 Once data are displayed use the O and keys to move the cursor right or left respectively in increments equal to the time history period LO 0 02 04 4 LxT_Data W Time History _ Leq x calculated using the selected interval at position Ist Time Parameter at position Leq instance Data and time at cursor position time cursor 58 5 dB 58 5 dB Total number of points measured Cursor position in multiples of time history period FIGURE 9 6 Measured Data at Cursor Position First Time History Parameter The time history graphs for Leq x and the selected time history parameter are overlaid on the display not visible in FIGURE 9 6 because the selected parameter is the same as the Leq x 9 8 In the above figure the value of the fi
184. o set the digit for that position When the desired value has been entered press the key Triggers Page 4 20 Exceedance Counter Levels SPL 1 de SPL 2 dB Peak 1 dB Peak 2 137 0 dB Peak 3 135 0 dB Close FIGURE 4 20 Triggers Page The Triggers Page is used to define threshold levels associated with exceedance events instances where the Dosimeter 1 and 2 Pages LxT Manual measured sound level exceeds the user defined threshold as shown in FIGURE 4 21 Exceedance Event Example FIGURE 4 21 Exceedance Event Example RMS Trigger Levels There are two threshold levels SPL Trigger Levels 1 and 2 which can be set to initiate an exceedance event when the measured RMS level Slow Fast or Impulse exceeds either of these thresholds LxT Manual Dosimeter 1 and 2 Pages 4 21 Exiting Measurement Property Screens 4 22 To exit the Measurement Properties Screen press the Center Softkey labeled Close If any setup parameters have been changed the Apply Changes message box will be displayed as shown in FIGURE 4 22 Apply Changes sic OBA a Settings Apply Changes FIGURE 4 22 Apply Changes At this point the parameter changes made from the Measurement Properties Screen have not yet been implemented in the instrument Use the O IES keys to select either Yes or No and press the GE key to implement the changes or cancel the changes respectively This will return the Data Display Screen
185. o the front of the instrument and the microphone connected to the end of the preamplifier If desired a microphone extension cable may be connected between the preamplifier and the body of the LxT For more details on the positioning of the LxT and the permitted length of the extension cable see Positioning the LxT on page 7 5 Making a Measurement 7 1 Switching On the LxT DO NOT use the hardware power With fresh batteries installed press the ON OFF switch to turn the LxT OFF This key shown in ON OFF Key on page 3 6 to switch on the may cause data to be lost See LxT Hardware Power Switch on page 2 7 for additional information on the use of the hardware power switch Start up Period The start up period will be less than twenty seconds As the instrument is starting up the display will show the following screen E vis INC Larson Da FIGURE 7 1 Boot Graphic Data View and Data Display screen When the LxT is fully started the Data Display Screen will refer to Live Overall and Session appear as shown in FIGURE 7 2 Data Display Screen Live Log Pages Page 7 2 Switching On the LxT LxT Manual Run Time Overload Icons Power Indicator LD 0 00 50 7 amp amp 4 E lt Measurement LxT_Data Status Live Overall SessionLog CE 140 o Section j lt indicator Live Page Scroll Bar LAeq 1s 86 2 dB Stability Las 86 2 dB Indicator LZpeak 96 9 dB FIGURE 7 2 Data D
186. od begins at 22 00 instead of 23 00 Thus by making this change in the Lpen formula the measured value will represent CNEL Integrated Level Calculations C 11 C 12 Integrated Level Calculations Model 831 Manual APPENDIX Allowed Exposure Time T LxT Manual Glossary This appendix contains technical definitions of key acoustical and vibration terms commonly used with Larson Davis instruments The reader is referred to American National Standards Institute document S 1 1 1994 for additional definitions Specific use of the terms defined are in the main body of the text It is the allowed time of exposure to sound of a constant A weighted sound level given a chosen Criterion Level Criterion Duration and Exchange Rate The equation for it is Le de c g Te l Upea NVO gla a where L is the Criterion Level T is the Criterion Duration Q is the Exchange Rate K is the Exchange Rate Factor and Lavg is the Average Sound Level Example If L 90 T 8 Q 3 and L 95 then 8 EE EE 8 et 1995 90 710 395 90 3 5 656 5 hours and 39 minu This means that if a person is in this area for 5 hours and 39 minutes he will have accumulated a Noise Dose of 100 Standard ANSI 12 19 Glossary D 1 Average Sound Level Layg Community Noise Equivalent Level CNEL Lgen 0700 It is the logarithmic average of the sound during a Measurement Duration specific time period using the cho
187. off When the overload is removed the icon will be removed from the display If a measurement is running and an overload occurs the icon shown below will flash during the overload all SLA When the overload has been removed the icon will still be present not flashing to indicate that an overload has occurred during the measurement A reset will clear the icon from the display If the input to the Octave Band Analyzer optional firmware LxT OBA required becomes overloaded the icon shown will appear to indicate the overload ra OBA Display Sections and Icons 3 3 Measurement Status 3 4 This icon operates similar to the Input Overload Icon shown in the above section Input Overload Icon When the OBA Range property is set to Low the OBA Overload Icon will activate at a level 30 dB lower than it would had the OBA Range been set to Normal Reset Icon DH The Reset Icon indicates that a reset has occurred Run Next Icon ll The Run Next icon appears when the Ei RUN PAUSE key is pressed and the LxT is waiting for filters and detector initialization to complete The LxT will automatically start the run after the wait or warm up state is completed Run Icon Lef The Run Icon moves from left to right to indicate that a measurement is running Pause Icon m The Pause Icon indicates that the present run has been paused Stop Icon m A Stop Icon is displayed when a measurement has been stop
188. oltage is too low When the battery is at the end of life the LxT will stop running save all data and instrument status then turn off When the unit is turned on again with fresh batteries or an external power supply the unit will return to the state it was in when it shut down FIGURE 16 5 External Power Icon If external power is supplied through the USB connector the battery icon is replaced with the External Power icon When external power is connected to the LxT the unit is not dependant on batteries The Estimated Run Time calculation is valid only if there is no external power External Power Supply The LxT cannot be operated under external power USB or from an external power supply if the internal batteries are discharged flat for reasons described in this section If there are no batteries installed in the LxT external power via USB or an external power supply will be utilized without host permission Thus you can remove depleted batteries and run on USB power only or power from an external power supply However LxT Manual The LxT can be powered from batteries or if available from the USB host portion of your computer It can also be powered externally using the PSA029 power supply as described in the section External Power Supply on page 16 7 External power whether provided via USB or an external power supply is negotiated with the host and cannot be utilized until permission is granted
189. on page 7 6 KS Effect of Windscreen on page A 14 7 3 Optional Accessories on page 1 10 7 4 Octave Band Analyzer Page Optional on page 4 13 7 5 No manufacturer provided auxiliary devices are provided 9 2 1 General a Standards Met on page A 1 b Configuration of the System on page 7 1 Sections 5 6 7 and 9 except 9 3 LxT Manual Section LxT Manual Comments c Standard Accessories on page 1 9 and Optional Accessories on page 1 10 d No microphone extension or microphone extension cable is required to meet specified standards e The LxT is a single channel instrument 9 2 2 Design Features a Parameters Measured on page 17 1 b Frequency Response on page A 16 c Table A 11 Sound Level Meter Specifica tions on page 10 d Table A 11 Sound Level Meter Specifica tions on page 10 e LxT Performance Specifications on page A 9 f The LxT measures sound level using a single range g LxT Main Characteristics on page A 3 and LxT Performance Specifications on page A 9 h Table A 10 Model 831 Performance Spec ifications on page 10 i Table A 11 Sound Level Meter Specifica tions on page 10 j Computer software is not an integral part of the LxT k None No optional frequency weightings 9 2 3 Power Supply a Power Supply Specifications on page A 5 and Internal Battery Operating Lifet
190. onds or Pascal squared hours PO is the reference pressure of 20 pPa and T is the reference time of 1 second It is then put into logarithmic form It is important to note that it is not an average since the reference time is not the same as the integration time The physical characteristic of sound that can be detected by microphones Not all pressure signals detected by a microphone are sound e g wind noise It is the amplitude of the oscillating sound pressure and is measured in Pascals Pa Newtons per square meter which is a metric equivalent of pounds per square inch To measure sound the oscillating pressure must be separated from the steady barometric pressure with a detector The detector takes out the steady pressure so only the oscillating pressure remains It then squares the pressure takes the time average and then takes the square root this is called rms for root mean square There are several ways this can be done Moving Average The averaging process is continually accepting new data so it is similar to an exponential moving average The equation for it is EMT t Pins IO t d S Glossary LxT Manual Sound Pressure Level SPL L LxT Manual p The sound pressure is squared and multiplied by a exponential decay factor so that when the time of integration is near the current time t it is essentially undiminished For times older less than the current time the value is diminished and so
191. onocococnnonoononnnonnonn non nonncon non rnon ron nncnncnnonos 9 20 Setting All Markers Of 9 21 Close Marker Control Window oooocccccncncccononnnononnononnonnononncnncanonnon 9 21 Markers Display oooooccccccococccccccccnocnnncnnnnnnnnoos 9 21 Chapter 10 Data Explorer Control Panel Data Explorer 10 1 Data EXplorer cocoa isis 10 2 Menu Softkey usina 10 3 NACW entien EEN 10 4 Delet ns n e A in ERE 10 5 Delete EE 10 5 Kemame iaa dina EENS EES 10 6 Refresh Dibus aci 10 8 Load Z tteg 10 8 Chapter 11 System Properties Control Panel System Properties 11 1 DOCE EE 11 2 Blo CN 11 3 Setting Day and Vedia ara 11 3 Selecting the Month tia 11 3 Sync Data Time with PE deiere ee ee 11 4 11 V111 MEET 11 5 Power Save MMe siren ee as 11 6 Backlight Time ii reren 11 7 Backlight Mode E 11 7 Display Contrast asesora rnnr reee 11 7 A 11 8 Pretoria 11 8 el o 11 9 Decimal Symbol morosidad sites 11 10 Date EE 11 10 e Ee EE 11 11 NONE eege ee Se hk haan ein nid he cS 11 11 PROM PU iss eessen 11 11 SLOPE E ad 11 12 Jack FUNCION e 11 12 USB OOO EE 11 13 Reset Prompting ccccccoonoccnnonoconononononnnos 11 13 Takt Maximal Data 11 13 DISD IAW Stata 11 14 EEN 11 14 Selecting Displays to Appesar 11 14 Tab Page Selection A E A TA 11 14 Display Selection ett atone ace ee 11 15 Chapter 12 Lock Unlock the LxT Control Panel Locke 12 1 Lock Modes EE 12 3 Unlocked nener a
192. ontrol Page is opened the Run Mode field will already be highlighted Press the Dat Enter key to open the Run Mode Menu Hans stop Manual Stop Timed Stop Stop When Stable Continuous Single Block Timer Daily Timer FIGURE 6 2 Run Mode Menu To set the mode use the 3 and keys to highlight the mode desired and press the ren Enter key to make the selection Each of the Run Modes is described in the following sections Run Control Setup LxT Manual Run Modes Manual Timed Stop Stop When Stable or Continuous Single Block Time or Daily Time Manual Stop Mode LxT Manual When the run mode used is Manual Time Stop Stop When Stable or Continuous this single measurement will run continuously from start time to end time However when Daily Auto Store has also been enabled with the Continuous run mode there will also be one or more blocks of data corresponding to 24 hour periods assuming that the measurement time encompassed at least one complete 24 hour period as programmed When the run mode is Single Block Timer or Daily Timer this single measurement will consist of data measured over different blocks of time between the start date and time and the end date and time a 0 00 00 0 Time Hisi Run Mode Manual Stop FIGURE 6 3 Manual Stop Mode The run mode is indicated as Manual Stop no further information is required Run Modes 6 3 Timed Stop Mode Entering Run Time 6 4 e
193. ork the proceedure described here is recommended LxT Manual The CAL200 provides a nominal pressure level of 94 dB or 114 dB The exact levels are printed on the Larson Davis calibration sheet that came with the calibrator When using a free field microphone the pressure level at the microphone diaphragm will be slightly different Thus a free field correction of 0 12 dB should be applied to either of these levels If the calibrator and instrument are near room temperature 23 C and near sea level 101 3 kPa then no other corrections need to be made If the calibration sheet for the CAL200 indicates 113 98 dB for it s level when set to 114 dB then set the Cal Level in the LxT to 113 86 dB and 1000 Hz When the microphone and instrument are at a temperature other than near room temperature or static pressures not near sea level then corrections will need to be added for the ambient temperature and the prevailing static pressure Check the calibration data shipped from Larson Davis with the CAL200 to get these corrections The corrections can be added to the level obtained in the previous paragraph to get the actual level of the CAL200 Calibrate 13 3 The 377B02 microphone s sensitivity varies with static pressure If the instrument is calibrated in one environment and moved to another then the sensitivity will change after stabilization depending on the change of temperature and pressure The coefficient of static pressure is
194. pass A frequency filter that permits signals to pass through that have frequencies above a certain fixed frequency called a lower cutoff frequency and below a certain fixed frequency called an upper cutoff frequency The difference between the two cutoff frequencies is called the bandwidth It is used to discriminate against both lower and higher frequencies so it passes only a band of frequencies Octave band A bandpass frequency filter that permits signals to pass through that have a bandwidth based on octaves An octave is a doubling of frequency so the upper cutoff frequency is twice the lower cutoff frequency This filter is often further subdivided in 1 3 and 1 12 octaves 3 and 12 bands per octave for finer frequency resolution Instruments with these filters have a sufficient number of them to cover the usual range of frequencies encountered in sound and vibration measurements The frequency chosen to describe the band is that of the center frequency Note table in Frequency Filter Frequency Weighting A special frequency filter that adjusts the amplitude of all parts of the frequency spectrum of the sound or vibration unlike band pass filters It can be composed of one or more of the following types A Weighting A filter that adjusts the levels of a frequency spectrum in the same way the human ear does when exposed to low levels of sound This weighting is most often used for evaluation of environmental sounds See table below
195. pecifications Specifications LxT Manual 1 1 and 1 3 Octave Filters The 1 1 and 1 3 octave filters OB1 and OB3 Options comply with all requirements of IEC 61260 1995 including amendment 1 2001 for Class 1 These digital filters are sampled at a rate of 51 200 samples per second with base X10 center frequencies and having real time performance for all filters The 0 dB gain setting is the reference range and the reference input signal is 1 Volt rms at 1 kHz Frequency Range 1 1 Octave Filters 8 Hz to 16 kHz 1 3 Octave Filters 6 3 Hz to 20 kHz Filter Shapes The following figures present the filter shapes for the 1 1 and 1 3 octave bands centered at 1 kHz Overlaid with these curves are the limit curves associated with IEC 61260 1995 Class 1 LxT Manual Technical Specifications A 11 A 12 O Sound Level Meter Model LxT Serial Number 0000033 Certificate of 1000 0 Hz Full Octave Filter Shape Larson Davis This Class 1 Sound Level Meter including attached PRMLXT1 preamplifier and ADP005 18pF input adapter was calibrated with a reference 1kHz sine wave The instrument s 1000 0 Hz filter response was then electrically tested using a 137 00 dBSPL sinewave at selected frequencies as specified in IEC 61260 am1 2001 09 10 00 0 00 10 00 20 00 30 00 40 00 50 00 60 00 70 00 80 00 90 00 100 00 1000 100000 Frequency Hz Measured Uncert Limits Freq Measured Uncert Limits dB d
196. ped Display Sections and Icons LxT Manual Softkeys Changing Views LxT Manual Store Icon When a data file has been stored the Store Icon is displayed Beneath the display on the body of the LxT there are three Softkeys as shown at the bottom of FIGURE 3 1 Data Display Screen Above each Softkey is a label which in this case will look as shown below The label indicates the action which will take place when the key is pressed Softkeys are so named because the role of each key can change depending upon the screen being displayed as indicated by the label In the Data Views the labels of the Left and Right Softkeys are left and right arrow symbols respectively These indicate that the Left and Right Softkeys are used to scroll the selection of the tab page being displayed in the corresponding direction One press of the Right Softkey will bring up the Overall Page and a second press will bring up the Session Log View Then sequential presses of the Left Softkey will bring up the Overall Page then the Live Page Display Sections and Icons 3 5 Keypad ON OFF Key Turn On The LxT Turn Off The LxT 1 See Chapter 3 Power Control View on page 3 7 3 6 The LxT has a 13 button keypad The upper 3 keys are discussed in the section titled Softkeys on page 3 5 The ON OFF key is used to turn the LxT ON and OFF If the instrument is OFF pressing this key will turn ON the instrument There will be a sli
197. posure OSHA Level LosHa Preamplifier Projected Noise Dose Single Event Noise Exposure Level SENEL Lax Sound D 16 _ 1007 4 4 4 T c D 0 L is TWA L is Criteria Level q is exchange rate factor see page D 8 Exchange Rate Q Exchange Rate Factor q Exposure Factor k Standard ANSI 12 19 See Sound Exposure The Average Sound Level calculated in accordance with the Occupational Safety and Health Administration Exchange Rate and Threshold Level A part of the sound level meter that matches a particular model of microphone to the meter It must be chosen in conjunction with a microphone and a cable that connects them It is the Noise Dose expected if the current rate of noise exposure continues for the full Criterion Duration period The total sound energy over a specific period It is a special form of the Sound Exposure Level where the time period is defined as the start and end times of a noise event such as an aircraft or automobile passby The rapid oscillatory compressional changes in a medium solid liquid or gas that propagate to distant points It is characterized by changes in density pressure motion and temperature as well as other physical quantities Not all rapid changes in the medium are sound wind noise since they do not propagate The auditory sensation evoked by the oscillatory changes Glossary LxT Manual Sound Exposure SE Sound Exposure Level SEL Lei
198. prior to performing a measurement The procedure for calibration is described in Chapter 13 Calibration on page 13 1 Positioning the LxT Observer Position The meter will be either mounted upon a tripod or held in the hand In order to avoid the effect of sound reflections from the body of the operator interfering with the measurement the meter should be located as far as possible from the body Thus when actually performing the measurement the operator should place himself at a distance behind the tripod mounted meter or extend the hand held meter as far from the body as is comfortable LxT Manual LxT Setup 7 5 Microphone Extension Cable Use of a Windscreen 7 6 If desired a microphone extension cable may be placed between the meter and the preamplifier microphone No correction is required when using Larson Davis Model EXCXXX microphone extension cables in lengths up to 300 feet XXX is the length in feet XXX 010 020 025 035 050 060 100 200 and 300 available When doing so take care that the preamplifier microphone is held or mounted in such a way to minimize the effect of reflections on the sound field near the microphone Wind blowing across the microphone generates pressure fluctuations on the microphone diaphragm which can produce errors in the measurement As a result when performing measurements in the presence of low level airflows it is recommended that a windscreen be placed over the microp
199. q Lmax Lmin SEL Lpeak Lpeak max 2 Sets of hygiene metrics Lavg TWA x Dose ProjDose Lep d E E8 E40 SEA peak exposure 2 RMS event counters and 3 Peak event counters Ly table displays 6 user selected Ly metrics Auto Store with Auto Reset Run Timer and Stop When Stable Control Real time clock Start time elapsed time and paused time Time stamping for Lmax Lmin Lpeak max metrics Session Log Lock functions Calibration with calibration history and list of calibrators Power management Status bar and About display Multiple languages Data files and Data Explorer Automatic data backup to prevent data loss on power failure Overall measurement Features LxT Manual Available Options Standard Accessories e Real time 1 1 Octave Frequency Analysis LXT OB1 e Real time 1 3 amp 1 1 Octave Frequency Analysis LXT OB3 e Automatic Data Logging with intervals from 1 second to 24 hours LXT LOG e Digital Voice Annotation LXT DVA includes SLM LxT Headset LXT IH e 120 MB Memory LXT MEM120 The LxT is delivered with the standard accessories described below Microphone and Preamplifier The LxT is delivered with one of the following combinations of microphone and microphone preamplifer Microphone Microphone Measurement Instrument P Microphone P Preamplifier Sensitivity Range LxT1 PRMLxT1 377B02 50 mV Pa 38 dB to 140 dB LxT2 PRMLxT2 7052 22 6 mV Pa 37 dB to 139
200. r 05 Time 20 14 41 Run Timer 0 00 10 2 Battery Hr o 0 USB Powered d ZN Memory 98 Free 7168kB of 7249kB 1 Data Files Started 2006 Mar 05 20 10 53 FIGURE 5 6 Live Page Section 5 Note If there is USB power the In Section 5 the status view indicates the current date and estimated battery time will not be a time the run time for the measurement battery voltage true representation of the available calculated run time and memory usage battery life Check this when operating on battery power only The Memory section indicates the amount of memory available as a percentage and in number of kBytes The number of stored data files is also indicated LxT Manual Live Page 5 7 Overall Page In this section we only address those sections of the Overall Page associated with basic sound level measurements Other pages associated with data provided by optional firmware may also appear Although the 1 1 and 1 3 octave spectra require optional firmware LxT OB3 we do include the display of this data in this chapter Leq Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 5 8 The Overall Page may have as many as thirteen sections To scroll between sections use the 7 or CA keys Use the Right and Left Softkeys to scroll between pages Laseg 59 5 dBEJ Las 36 3 dB Started 2006 Apr 21 17 26 01 FIGURE 5 7 Overall Page Section 1 The g
201. raph in Section depicts the average sound level for the last 120 seconds of the measurement The run time for the average calculation is shown at the top of the screen The graph is updated once per second and the calculation of the average sound level is updated approximately four times a second Overall Page LxT Manual The Laseg frequency weighting A and detector response Slow is the equivalent sound level based on the run time of the measurement The Lag is the instantaneous measured level from the RMS detector The time at the bottom of the page is the date and time the measurement was started Maximum Minimum and Peak Sound Levels LxT Manual LxT_Data IHR Overall ESTE Laseq 104 7 dBEJ Las 53 6 dB LZpeak 87 1 dB LZpeak max 127 3 dB 2006 Jun 14 14 35 21 LASmax 113 6 dB 2006 Jun 14 14 35 19 LASmin 47 7 dB 2006 Jun 14 14 35 15 Run Time 0 00 11 4 FIGURE 5 8 Overall Page Section 2 Laseq and the Lag are also shown in Section 2 of the Overall Page The Lzpeak Z frequency weighting is the current measurement from the peak detector The Lzpeak max 18 the highest level the peak detector has measured during the run time of the measurement A date and time of occurrence is recorded with this event Overall Page 5 9 See Chapter 3 RESET Key on page 3 8 5 10 The Lzpeak max S also considered the peak hold Whenever data is reset this parameter is cleared To reset data pre
202. rds there is a linear relationship between the Criterion Level and the Time When Auto Calculate is activated by checking the check box to the left then only one of these need be entered and the other will be automatically set to follow the standard Dosimeter 1 and 2 Pages 4 11 Ln Page 4 12 lt gt 0 00 00 0 0 Dosimeter2 Popa contf Ln Percentiles 1 EI 10 00 33 30 66 60 2 3 4 Yo 5 6 90 00 Close FIGURE 4 9 Ln Page The Ln value is the measured sound level which was exceeded n of the measurement time For example a value of Loy 35 dB means that the measured sound level was above 35 dB for 90 of the measurement period These statistical values are commonly used to describe the characteristics of non steady sound such as environmental noise The LxT can calculate six different Ln values based on user defined values of n which can be in the range 00 01 to 99 99 Using the C 7 and CH keys select the desired Ln percentage to change Press the key Use the C E and 11 keys to adjust the value to the desired Ln percentile Press the key to accept this new value Use the same procedure to modify other values as needed Dosimeter 1 and 2 Pages LxT Manual Octave Band Analyzer Page Optional OBA Range Setting OBA Bandwidth Setting LxT Manual This page will only appear when the LxT has the optional LxT OB1 or LxT OB3 firmware enabled OBA Range Normal O Low 1 1
203. re preferences are enabled in this mode See Chapter 12 Fully Locked on page 12 6 A measurement cannot be reset when the Model LxT is locked in any mode Control Panel Lock 12 3 Unlock Code 12 4 Move the highlight to the Unlock Code Field gt 0 00 00 0 0 Lock Mode Fully Locked e Unlock Code Enter a 4 digit code to use when unlocking this unit WO O llow Cal When Locked FIGURE 12 4 Unlock Code Press the key The 1st character in the field will be highlighted Use the C E O or D keys to select the desired_unlock code To accept the new unlock code press the ED key Press the Close soft key to exit the Lock Page Control Panel Lock LxT Manual Allow Cal When Locked LxT Manual 5 0 00 00 0 0 Lock Mode Fully Locked e Settings Apply Changes ves Mo O allow Cal When Locked FIGURE 12 5 Apply Changes Make the choice whether to le 3 changes using the or keys and then press the res key to complete the process Move the highlight to Allow Cal When Locked Pressing the key will toggle the state of the check boxes shown in FIGURE 12 6 Allow Cal Check Box If the box is checked calibration will be allowed while the unit is locked but not running a measurement Control Panel Lock 12 5 5 0 00 00 0 0 lock Lock Mode Unlocked e Unlock Code Enter a 4 digit code to use when unlocking this unit x Allow Cal When Locked FIGURE 12
204. rement Properties Pages The frequency weighting for RMS and Impulse averaged sound levels will be the same selected independent from the frequency weighting for peak detection RMS and Impulse Weighting The LxT measures RMS and Impulse averaged sound level values using one of the following user selected frequency weightings e A Weighting e C Weighting e Z Weighting LxT Manual Parameters Measured 17 1 RMS Averaging 17 2 Peak Weighting The LxT measures peak sound level values using one of the following user selected frequency weightings e A Weighting e C Weighting e Z Weighting The exponential averaging time for RMS sound levels is set to one of the following e Slow e Fast An impulse detector is also available Basic Sound Level Measurements LxT Manual Sound Level Metrics Measured Metric Instantaneous Sound Level Selected RMS Averaging In Table 17 1 Sound Level Metrics Measured the symbol X is used to represent the user selected RMS and Impulse frequency weighting A C or Z and the symbol Y is used to represent the user selected peak frequency weighting A C or Z The symbol V represents the time weighting Fast Slow or Impulse Impulse Integrated Ly peak Maximum Sound Level Minimum Sound Level Ly peak max Equivalent Level Table 17 1 Sound Level Metrics Measured 1 1 and or 1 3 Octave Frequency Spectra LxT Manual The LxT can perform just
205. rement Setting Screen as shown in Figure 6 1 Run Mode Manual Stop v Close FIGURE 6 1 Control Page The Control Page is used to set the Run Mode for the measurement to be performed There are six modes of measurement duration available e Manual Stop The measurement is initiated manually by pressing the C Run Pause key and it is stopped by pressing the Stop key LxT Manual Run Control 6 1 e Timed Stop The measurement is initiated manually by pressing the Run Pause key and will be stopped automatically after a user defined time period e Stop When Stable The measurement is initiated manually by pressing the Run Pause key The measurement will stop when the measured level has remained within a user defined range and the measurement has run for a user defined time period e Continuous The measurement is initiated manually by pressing the Run Pause key and it is stopped by pressing the Stop key Measurements are made continuously from start to stop e Single Block Timer The measurement is initiated manually by pressing the E Run Pause key and it is stopped by pressing the 22 Stop key Measurements are made only during the time interval defined by the single block timer Daily Timer The measurement is initiated manually by pressing the Run Pause key and it is stopped by pressing the 22 Stop key Measurements are made only during the separate time blocks defined by the setup When the C
206. rophone the incident wave must be reflected since it cannot pass through the microphone This results in the extra force required to reflect the sound and a microphone output that is higher than would exist if Glossary D 13 Near Field D 14 the microphone were not there This is more important at high frequencies and when the microphone is facing the sound source Rules 1 Do not use a microphone at frequencies higher than specified by the manufacturer to increase the frequency response choose smaller microphones 2 Choose a microphone for free field or random incidence to minimize the influence of orientation A microphone measures what is there from any direction Most measurements are intended to measure the sound level of a specific source but most microphones are not directional so they measure whatever is there regardless of source Rules 1 When making hand held measurements keep your body at right angles to the direction of the sound you are interested in and hold the meter as far from your body as possible Use a tripod whenever possible 2 Measure the influence of other sources by measuring the background sound level without the source of interest You may have to correct for the background There are two types of near fields the acoustic near field and the geometric near field Acoustic Near Field The distance from a source of sound is less than an acoustic wavelength In the near field the effect of the
207. rst of the time history parameters in this case Leq is displayed for the cursor position To display the value of this parameter for other samples use the and keys to select a different cursor position Time History Display LxT Manual Displaying Other Time History Parameters When repeatedly pressing the lt 2 key the logged parameter values will be displayed in the same sequence as they appeared in the list when selected as described in Select Time History Parameters on page 9 6 Selected Display Lpeak Time History Leq x where x is the time As explained in section Parameters Logged on page 9 1 the user can select to log up to sixteen different parameters as a function of time setup as described in section Select Time History Parameters on page 9 6 The default value is the first parameter selected during the setup procedure By pressing the gt and C keys the value displayed can be shifted to represent a parameter one later or earlier respectively in sequence in the user created list of parameters to log For example in FIGURE 9 7 we have pressed the lt gt key to select Lpeak the next parameter in the selection sequence at the same cursor position used to graph and display Leq in FIGURE 9 6 LD 0 03 18 6 LxT_Data METIA Time History Parameter cura OT m EE O te Me el eS EE wb history interval FIGURE 9 7 Time History Graph and Value of LApeak at Same Tim
208. s FIGURE 10 6 Delete All Files Highlight the appropriate response using the 6 or O keys and the Enter key Data Explorer 10 5 Rename The Rename menu item enables you to change the name of the selected data file Pressing the as Enter key brings up a message box for editing the file name Eu Rename File FIGURE 10 7 Rename File Highlight the text box with the file name Press the Enter key and the first character in the file name will be highlighted Using the 7 E 6 and O keys modified the file name Press the Ge Enter key to complete the changes Highlight the Yes button to accept the changes or the No button to discard the changes the press the Ge Enter key If your new file name is the same as a file already in the directory an Overwrite message box will appear See FIGURE 10 10 Overwrite Confirmation If you select Yes then the old file will be over written with the newly named file A response of No will return the Rename message box Use the or keys to make a selection and press the as Enter key 10 6 Data Explorer LxT Manual Overwrite an Existing File Another method of renaming a file is to overwrite a stored file Highlight the button and press the as Enter key to display a list of file names as shown in FIGURE 10 8 LxT_Data 002 LxT_Data 003 LxT_Data 004 Lat LxT_Data 005 LxT_Data 006 LxT_Data 007 LxT_Data 008 LxT_Data 009 FIGURE
209. s a unit called Bel is created The decibel stands for deci for one tenth and bel for Bel compare decimeter The relationship between Bel and decibel is thus 1 Bel 10 decibels It is not possible to directly add or subtract decibel values since addition of logarithmic values correspond to multiplication of the original quantity Glossary D 5 Power form squared units Level form Ration of Value to Reference Expenential Fomor EES Ratio 1 10 0 10 10 10 100 10 20 200 10 23 1 000 10 30 10 000 10 40 100 000 10 50 1000 000 10 60 Each time the sound pressure level increases by 6 dB the corresponding sound pressure value is doubled and thus multiplied by 2 Each time the sound power level increases by 3 dB the sound power value is multiplied by 2 Thus it is important to notice that a doubling of the sound power is equal to 3 dB and a doubling of the sound pressure is equal to 6 dB since a doubling of the sound pressure will result in a quadruple increase of the sound power The advantage with using dB is simply that they remain the same even if we use sound pressure or sound power Compare this to the use of voltage and power units in electrical engineering units being related by P V In table 2 an illustration is made of values calculated on sound pressure non squared units The original definition of decibel was intended for power like quantities such as so
210. sability or veteran status Please examine your instrument and record the following information below You may be asked to give this information in any future communications you have with Larson Davis Inc Customer Service In the U S call toll free 888 258 3222 International customers 1 716 926 8243 FAX 1 716 926 8215 Email techsupport LarsonDavis com Worldwide Web www LarsonDavis com 1 11 LxT Manual Record of Serial Number and Purchase Date LxT Model LxTl LxT2 Serial Number Preamplifier Model Serial Number Microphone Model Serial Number Recycling Larson Davis Inc is an environmentally friendly organization and encourages our customers to be environmentally conscious When this product reaches its end of life please recycle the product through a local recycling center or return the product to Larson Davis Inc Attn Recycling Coordinator 1681 West 820 North Provo Utah USA 84601 where it will be accepted for disposal LxT Manual i iii i iv LxT Manual Table of Contents Chapter 1 Introduction About This Manual 1 1 Special Features of the Electronic Version 1 3 BOOK Markt roses as 1 3 Opening Bookmark iaa 1 3 Closing Bookmarks ooocononocnoccnoonoonoononnonncnnnonncnn non non nron nc nnnn nr nanannos 1 4 Expanding Bookmarks 1 4 Click to Display a Page cooooooonnociconoonnocnnononnconnonncon non cono non cnn nocn non nanannnos 1 5 Return to Previous View 1
211. sen Exchange Rate Factor Exposure to this sound level over the period would result in the same noise dose and the actual unsteady sound levels If the Measurement Duration is the same as the Criterion Duration then Lave LTwA LC T 1 Lig qLogio d 10 Ti DN A y where the Measurement Duration specified time period is T T T and q is the Exchange Rate Factor Only sound levels above the Threshold Level are included in the integral Standard ANSI 12 19 A rating of community noise exposure to all sources of sound that differentiates between daytime evening and nighttime noise exposure The equation for it is 1900 2200 2400 1 L 10 10 L 10 L 5 10 L 10 10 Lion 1010810 24 10 D 10 gt 10 gt 10 0000 0700 1900 2200 The continuous equivalent sound level is generally calculated on an hourly basis and is shown in the equation as L The levels for the hourly periods from midnight to 7 a m have 10 added to them to represent less tolerance for noise during sleeping hours The same occurs from 10 p m to midnight The levels for the hourly periods between 7 p m and 10 p m have 5 added to them to represent a lessened Glossary LxT Manual Criterion Duration T Criterion Sound Exposure CSE Criterion Sound Level L Daily Personal Noise Exposure LEP a Day Night Average Sound Level DNL Lan LxT Manual tolerance for noise during evening activities They are energy summed and convert
212. sound level meter There are several speeds used Slow The time constant is 1 second 1000 ms This is the slowest and is commonly used in environmental noise measurements Fast The time constant is 1 8 second 125 ms This is a less commonly used weighting but will detect changes in sound level more rapidly Impulse The time constant is 35ms for the rise and 1 5 seconds 1500 ms for the decay The reason for the double constant is to allow the very short signal to be captured and displayed The oscillatory movement of a mechanical system generally taken to be solid It is used as a broad descriptor of oscillations The distance between peaks of a propagating wave with a well defined frequency It is related to the frequency through the following equation E EE Glossary LxT Manual Wavenumber k LxT Manual where c is the sound speed and fis the frequency in Hz It has the dimensions of length A number that is related to the wavelength of sound and is used to compare the size of objects relative to the wavelength or the time delay in sound propagation It is related to wavelength through the following equation 2n _ 2nf o ETI c c where A is the wavelength c is the sound speed f is the frequency in Hz and o is the radian frequency It has the dimensions of inverse length Glossary D 23 D 24 Glossary LxT Manual APPENDIX Warranty Customer Satisfaction A Total Customer Satisfaction Larson
213. ss the 5 RESET key The Lagmax is the highest level the RMS detector has measured during the run time of the measurement A date and time of occurrence is recorded with this event The L Asmax S also considered the max hold Whenever data is reset this parameter is cleared To reset data press the gt RESET key The Lasmin 18 the lowest level the RMS detector has measured during the run time of the measurement A date and time of occurrence is recorded with this event Overall Page LxT Manual 1 1 Octave Band Analyzer Optional The 1 1 Octave Band Analyzer display appears only when the optional firmware LxT OB1I or LxT OB3 has been enabled and this measurement mode has been selected in the setup Lmax Values Leq Values Lmin Values Frequency Spectrum Bandwidth p A am 1 Ma Frequency Weighting and Time__y 2 Fast Leq 85 6 dB Averaging for Spectral Measurements Lmax 99 7 dB Lmin 46 0 dB Run Time 0 00 08 0 Spectral Measurements Leq Lmax and Lmin Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 LxT Manual FIGURE 5 9 Overall Page Section 3 The data displayed in in Section 3 shows Leq Lmax and Lmin sound levels in 1 1 octave frequency bands calculated for the duration of the measurement The right most bar on the graph is the sum of the Leq values for the total spectrum The bar for the displayed frequency band is highligh
214. sured Data at Cursor Position First Time History Parameter 9 8 Time History Graph and Value of LApeak at Same Time as FIGURE 9 6 111 111 9 9 Time History Display with Frequency Spectrum Data Logged 9 11 Time History Display with Frequency Spectrum as Displayed Parameter EE 9 12 1 1 Octave Leq Spectrum Time Sample 2 9 13 1 1 Octave Leq Spectrum Time Sample 5 9 14 Enter gt By 1 1 Frequency To Display 1 1 Octave Spectrum 9 15 Enter gt By 1 3 Frequency To Display 1 3 Octave Spectrum 9 16 Enter gt By Time To Display Time History ooooooiccccncnoccccccccccncnnnnn 9 17 Markers Setup Window Markers 1 P 9 18 Markers Setup Window Markers 6 10 9 19 Marker H 9 19 Menu Options A iiO 9 20 Time History Display with Markers seseeeeeeeeeeeeereeeeesesserreereee 9 20 Marker Indication on Time History Display ooooooooonocnnnnnnnncnnncnns 9 21 Data Explorer nus ia iio 10 1 Control PAMELA nd aa a ee 10 1 Data EXPO A NEE 10 2 Data Explorer Men osa iene EEN 10 3 Data View Pages tee 10 4 A EE 10 5 Delete AMES ais Ee Ee 10 5 Rename FG A ANTAS A A 10 6 Pile Name List A A a 10 7 Selection of File to be Overwritten ooooooooooonnnconoconnnnccnnononons 10 7 Overwrite Confirmation ai 10 8 System Properties circos eege 11 1 Control Panel anar 11 1 Device Pag usais ibi ae 11 2 MMe EE 11 3 Monta Fists cis o rara o e od ral N as 11 4 Power Page aria e
215. ta to replace a data file already saved in the LxT instead of highlighting Yes_or No highlight the box with the title and press the key This will open a window listing all the data files already saved in the LxT as shown in FIGURE 7 10 J ixT_Data 002 LxT_Data 003 LxT_Data 004 LxT_Data 005 LxT_Data 006 LxT_Data 007 LxT_Data 008 FIGURE 7 10 Saved Data Files Use the 7 and CH keys to select the file which is to be overwritten and press the key This will replace the file name and number which previously appeared with this one as shown in FIGURE 7 11 EAJ Save File Yes No Kc Laeq 1s 51 9 dBEL Las 51 6 dB L2peak Started 2006 Jun 14 16 06 46 Storing the Measurement 7 15 Low Level Sound Fields 7 16 FIGURE 7 11 Overwriting a Saved File To continue with the overwrite operation use the O key to highlight Yes and press the key This will open the Overwrite Confirmation menu shown in FIGURE 7 12 0 00 00 0 LD LxT_Data 001 Overwrite File FIGURE 7 12 Overwrite Confirmation Highlight Yes and press the key to implement the overwrite operation To abort the overwrite operation use the O key to highlight No and press the key To select a different previously saved file to overwrite use the key to highlight the box with the title and press the key to repeat the overwrite procedure As long as the sound level being measured is within the measurement r
216. tatic Actuator WS Wind Screen 0 Free Field 0 Free Field 0 Free Field Corrections 0 Free Field Corrections expanded Corrections with WS Corrections with WS uncertainty from from from from of Corrections B amp K 4226 B amp K 4226 B amp K UA0033 B amp K UA0033 95 Frequency Calibrator Calibrator EA EA confidence Hz dB dB dB dB dB 31 62 0 2 0 2 0 0 0 1 0 25 63 10 0 1 0 2 0 0 0 1 0 25 125 89 0 0 0 1 0 0 0 1 0 25 251 19 0 1 0 1 0 0 0 1 0 25 501 19 0 0 0 0 0 1 0 1 0 25 1000 00 0 0 0 0 0 0 0 0 0 25 1995 26 0 6 0 9 0 6 0 9 0 30 3981 07 1 1 1 1 1 0 1 0 0 35 7943 28 2 3 1 9 2 9 2 6 0 40 12589 25 5 2 4 4 6 8 6 0 0 50 15848 93 5 4 4 3 8 1 7 0 0 60 add numbers in this column to levels read on the LxT to correct to the 0 Free Field level e Linear Operating Range A weighted sound levels for the LxT1 at the upper and lower limits of the linear operating ranges 31 5 Hz 1 kHz 4 kHz 8 kHz 12 5 kHz 78 dB to 100 6 dB 36 dB to 140 dB 35 dB to 139 dB 37 dB to 138 9 dB 40 dB to 135 7 dB f Linear Measurement Starting Level The starting point for measuring level linear errors on the reference range is 114 dB LxT Manual LxTl B 11 g Electrical Insert Signals The electrical design of the input device to insert electrical signals into the preamplifier is a series 18pF 5 capacitor The Larson Davis ADP0OS is used for this purpose The ADP005 can b
217. ted The highlight can be moved using the O and keys Overall Page 5 11 Leq Lmin Lmax 5 12 Leq is the energy average sound level of the frequency band for the duration of the measurement Linin 18 the minimum sound level of the frequency band for the duration of the measurement The value of Lmax depends upong the choice of Max Spectrum Mode selected in the OBA setup described in OBA Max Spectrum Mode on page 4 15 Bin Max When the Max Spectrum Mode is Bin Max then the value of Lmax for each frequency band is the maximum value which occurred in that band during the entire measurement period Since individual frequency bands may reach their maximum levels at different times this spectrum might be one which never occurred at any instant during the measurement period At Max When the Max Spectrum Mode is At Lmax the Lmax spectrum is the actual spectrum which was measured at the instant that the measured sound pressure level achieved its maximum value As a result this is an actual spectrum which occurred during the measurement period and it represents the frequency content of the signal which produced the maximum instantaneous sound pressure level Overall Page LxT Manual 1 3 Octave Band Analyzer Optional The 1 3 Octave Band Analyzer display appears only when the instrument is loaded with the optional LxT OB3 firmware and this measurement mode has been selected in the setup Note th
218. tee EE Ee ee ebe 13 1 e EE 14 6 Criterion nit sd A RN Bente Bee eee D 3 RL D 3 Gross References iii er a 1 6 a 2 LxT Manual Current Date and Time svc ie er eee oe ea ee ee 5 7 RTE e TT e nd i ii D D ta E 7 2 Data Display 1 1 Octave Band Analvzer E EEE E E EE 5 4 1 3 Oct v Bandt Analy Ze ecnin E a eee 5 5 RE 5 1 ES oes A ee th es a 5 18 E A EEE EE E E A 5 23 LG EE 5 8 Ee 3 14 A a e E 5 2 En e AAEE EEE NE E EAEN E EEE DAE IE E EE A 5 17 Max Min and Peak Sound Levels 5 9 No Of Measurements rre e EE TE EAE EE E E E e 5 22 Number of Measurements ranee Ee S EA E a o aeS 5 20 Octave Band Adal Zi E ease ee eege 5 11 5 13 Overa eases E caches E E N te custo css Doane name N eb aha E NE 3 14 RN EE 5 19 SESSION LOS Ee E AW Ei A ee ie eas 3 14 5 22 Sound Level Prol ee eege a EEN E IOIA 5 3 Tabbed Page Structure ennei horde a 5 1 Time HAStOry s 25 eess spose e e ad dane e eee 3 14 Time Battery Voltage and Memor 5 7 TAG BOTAN ee cadence shasta eege ees de 5 6 Data Display akeeft eegene ee E 3 1 3 13 3 14 Data EXPO AE e A sia 10 1 e 10 1 Ee E e Mestad sean 10 1 Control Haneboesch reese e eege ee 10 1 Data View A onran i e a E aao i a EA a E aaae stae 10 4 Delete AMES eet eh a eu Eege 10 5 elteren RR EEA E EN 10 5 End Dataand MM Seege Ee ee E 10 2 Lee IN rte ege ee Eed EE 10 2 Load Sieten Metin Rll AG NEA ek eh i eh a ado 10 8 Refresh File List 10 8 Rename des rt aa 10 6 Start Date atid ne ii ie EE 10 2 Test Descr
219. tes how the requirements are met in the LxT LD 0 08 03 9 il The numerical value for the TWA and Proj TWA Time weighted average TWA based on 8 hours The Projected Time Weighted Average for 8 hours The currently selected Frequency Weighting A and Detector Response Slow for SPL The currently selected Exchange Rate Threshold Level Elapsed measurement time shown as h mm ss s Note that the LxT displays the time weighted average as TWA Hr where Hr is the time in hours over which the average is performed FIGURE C 1 TWA The actual equations used within the LxT are based on those for IEC 61672 1 and are implemented according to this equation n Lis Lrwa Lea ke log gt 10 T log n s 1 Model 831 Manual Integrated Level Calculations C 3 Note that the LxT displays SEL as Lyg where X is the frequency weighting X A C or Z C 4 where La is the current SPL at sample s for measurements that include a threshold La is set to x if Lais less than the Threshold Level L k is the exchange rate constant which is equal to 10 00 for an exchange rate of 3 dB Leq 13 29 for an exchange rate of 4dB Lpop 16 61 for an exchange rate of 5dB Losa 20 00 for an exchange rate of 6dB L Avg n is the total number of samples taken in the measurement The sample rate is 32 samples per second Lea is the calibration offset that corrects for various sensitivities of microphones
220. the CT CH 6 or O keys to highlight System Utilities icon on the Control the System Utilities icon as shown in FIGURE 15 Panel 1 Control Panel 0 00 00 0 ZS D Kl ei System Voice Properties Recorder al E System Utilities About FIGURE 15 1 Control Panel Press the key to open the System Utilities Page There is one System Utilities Page File System LxT Manual System Utilities 15 1 File System Warning Using these functions may cause loss of data and restoration of the LxT to default conditions 15 2 The File System page is used to repair or recover from file system problems The functions available on this page are similar to function that would be used to manage a hard drive See FIGURE 15 2 File System ES 0 00 00 0 System Utilities File System Check File System Format Format Restore Defaults FIGURE 15 2 File System The three functions on the File System page are e Check File System e Format e Format amp Restore Defaults Use the C and keys to select the desired function Press the key to initiate this operation The user should only activate these functions if there appears to be a problem File System LxT Manual Check File System Format Format amp Restore Defaults LxT Manual These utilities will detect and repair file system problems When the Check File System button is selected the LxT will check the file system in the LxT similar to Ch
221. the contrast of the display to compensate for temperature changes Press the Left Softkey labeled Off to turn off the LxT Pressing the Right Softkey labeled Setup takes you to the System Properties Device Page See Chapter 11 System Properties on page 11 1 Keypad 3 7 The Center Softkey provides an exit escape or cancel function as well as the function displayed above it on the display RESET Key If desired the LxT can be set to display a Reset Prompt menu prior to the completion of a reset operation as described in Reset Prompting on page 11 13 Pressing the Center Softkey labeled Close will close this screen and return to the Data View screens To reset a measurement in progress press the amp RESET key This will erase all data previously measured and reset the run time clock to zero A reset will not reset stored data files A reset can be initiated when the LxT is running paused or stopped However it must be stopped for the reset operation to be performed Resetting When Running or Paused 3 8 If it is running or paused when the D RESET key is pressed a Stop Required Menu will be displayed as shown in FIGURE 3 3 Stop Required Cancel 32 9 dB EZ ES Las 32 8 dB LZpeak 60 5 dB Started 2006 Apr 21 13 58 10 FIGURE 3 3 Stop Required Prompt The OK response will already be highlighted so simply press the ENTER key to continue Keypad LxT Manual Resetting When S
222. the integration time For long duration measurements both integration methods report the same value in that they both have equivalent energy under the curve although short term metrics may vary Setup Pages LxT Manual Dosimeter 1 and 2 Pages Name Exchange Rate Threshold Be Enabled 090 0 de Criterion 090 01 de Hr O Auto Calculate d Close FIGURE 4 5 Dosimeter 1 The Dosimeter 1 and Dosimeter 2 Pages are provided to permit the evaluation of two independent noise dose data sets Other than being on separate pages they are identical LxT Manual Dosimeter 1 and 2 Pages 4 7 Predefined Setups In most cases measurements of this type are setup to conform to a specific standard The LxT permits the user to create such a setup in a single step by simply selecting the applicable standard The standards addressed by the LxT and the corresponding parameters are as shown in Table 4 1 Predefined Noise Dosimeter Setups Standard Pechange Threshold Criterion Rate Level Hours OSHA 1 5 90 90 8 OSHA 2 5 80 90 8 ACGIH 3 80 85 8 NIOSH 3 80 85 8 IEC 3 Not Enabled 85 8 Table 4 1 Predefined Noise Dosimeter Setups The Name field will already be highlighted when Dosimeter View is opened If this has been changed use the CY key to move the highlight back to the Name field 4 8 The names of the predefined setups can be accessed from the Name field at th
223. this standard e Appendix C Integrated Level Calculations provides information on TWA Leq SEL Dose and Projected Dose calculations e Appendix D Glossary Contains technical definitions of key acoustic and vibration terms e Appendix E Warranty Customer Satisfaction A presentation of warranty and customer satisfaction policies Special Features of the Electronic Version There are a variety of special techniques for navigating through pdf documents which can greatly simplify finding specific items in this manual Three of these bookmarks links and cross references are discussed below Bookmarks Opening Bookmarks Bookmarks are clickable navigation tools in pdf files To open a bookmark left click the upper tab on the left of the screen labeled Bookmarks These will appear as shown FIGURE 1 1 LxT Manual Special Features of the Electronic Version 1 3 Closing Bookmarks Expanding Bookmarks L Table of Contents L List of Figures L List of Tables L Introduction L First Use L Overview L Basic Measurement Setup L Basic Data Display z Run Control L Making a Measurement L Voice Recording L Time History L Data Explorer Y System Properties L Lock Unlock the LxT L Calibration L About L System Utilities L LxT Hardware Y Parameters Measured L Technical Specifications L Testing to IEC61672 1 L Integrated Level Calculations L Glossary L Warranty
224. tically When the recording has been stopped the Save Prompt shown in FIGURE 8 4 will appear 0 00 00 0 d voice 2006 Mar 05 20 41 53 Save Recording FIGURE 8 4 Save Recording Prompt Select Yes to save the recording or No to close the recording session without saving the recording Playback Button L gt To playback a highlighted voice record press the Right Softkey With a headset attached to the headset jack on the bottom of the case you will hear the voice recording in the headset speaker Voice Recorder LxT Manual LxT Manual ES 0 00 00 0 FIGURE 8 5 Playback The meter indicates the relative amplitude of the recorded sound The progress bar indicates the elapsed time of the playback of the recording The progress bar length represents the actual recording time Press the key to stop the playback At the end of the voice record the playback will stop automatically Voice Recorder 8 5 Voice Recorder LxT Manual CHAPTER Time History This chapter describes the measurement features associated with the optional data logging firmware LxT LOG Parameters Logged Acoustical Parameters Sound Pressure Level Values LxT Manual Using the Time History mode the LxT can automatically log up to sixteen parameters both acoustic and non acoustic at time intervals ranging from one second to twenty four hours RMS Levels The following RMS sound pressure level values measur
225. time during the first seven years of the product life from date of manufacture The customer s sole remedy pursuant to this extended warranty is to receive free labor for any repairs required during the period in which the extended warranty is effective This extended labor warranty is subject to the limitations as outlined in Paragraph J Service amp Repair Limited Warranty In addition to the limited warranties set forth above LD offers a 90 day parts and labor limited warranty for all repair work performed at the factory This warranty is limited to parts repaired or replaced at the factory by LD This warranty is also subject to the limitations as outlined in Paragraph J C Shipping Charges The buyer will return the product freight prepaid by the Buyer to an authorized service center The product will be returned to the buyer freight prepaid by LD D Products Manufactured by Others This Limited Warranty does not cover any products manufactured by others Such products are subject to the warranty if any of their respective manufacturers and to be repaired only by a respective authorized service person for such products LD shall have no obligation to undertake repairs of products manufactured by others LxT Manual Warranty Customer Satisfaction E 1 E NO SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES LD S SOLE OBLIGATIONS UNDER THIS LIMITED WARRANTY ARE SET FORTH ABOVE IN PARAGRAPHS A B C AND D IN NO EVENT SHALL LD ITS CONTRACTORS
226. tive listed under Sales on the Larson Davis web site www LarsonDavis com 14 4 The Options Page lists available options for the LxT A check mark next to an option indicates that the option is enabled See FIGURE 14 4 Options Page ay 4 12 11 2 2 Ka DEE Options DN Enabled Option Name 1 1 Octave 1 3 Octave Voice Annotation Time History Industrial Hygiene Close FIGURE 14 4 Options Page Options LxT Manual User This page displays any identifying information the user may have entered on the System Properties Device Page or using Blaze software See FIGURE 14 5 User Page 0 00 00 0 MH System Properties Device Instrument Identification FIGURE 14 5 User Page LxT Manual User 14 5 Credits 14 6 Just like a major motion picture it takes a large staff of experienced professionals working long hours behind the scenes to produce a product like the LxT We are pleased to present a rolling list of credits to acknowledge these individuals for their valuable contributions Product Specification Alain deLandsheer Alan Rasmussen Craig Smith Ken Cox Rob Brauch Hardware Desiqn Alan Rasmussen Curtis Thompson Leroy Harbaugh FIGURE 14 6 Credits Credits LxT Manual System Utilities Control Panel System Utilities Note It is necessary to press the CI To activate the System Utilities Page press the A key one time in order to see the TOOLS key Use
227. to a USB memory device instead of to internal memory Use the C3 and CU keys to highlight the USB Storage field and press the key to obtain a listing of the choices as shown in FIGURE 11 11 FIGURE 11 12 USB Storage Preferences To have data stored to the USB memory device use gt CJ and keys to highlight Auto and press the key to make the selection To have data stored to internal memory use the 7 and CH keys to highlight No and press the key to make the selection If the Reset Prompting check box is checked the user will be prompted with an Are You Sure message box whenever the gt RESET key is pressed If it is not checked this prompt will not appear prior to the reset action taking place Use the CJ and CH keys to dee the Reset Prompting check box Pressing the GE key toggles the state of the check box When this is checked the parameter LAFTMS is also measured and displayed on the Community Noise Page of the Overall Screen and as a parameter of a Time History measurement Preferences 11 13 Displays Start The Displays page permits some customization of the displays The user can select to have one of the following displays appear when the LxT is switched On With the Start field highlighted press the key to obtain a list of options as shown in FIGURE 11 13 Display Start Options Use the 7 and C keys to highlight the Display Start option and press the key to make the selection
228. to highlight the Data Explorer icon as shown in FIGURE 10 1 Control Panel FIGURE 10 1 Control Panel Press the key to open the Data Explorer Page Press the Close Softkey to exit from this page LxT Manual Data Explorer 10 1 Data Explorer 10 2 There is one Data Explorer Page It shows a directory of all the stored data files There is a scroll bar to indicate the relative position in the list of data files There may be more data files in the directory than are displayed on this page All files may be viewed by scrolling through the list LD LxT_Data 001 2006 Jun 14 14 47 26 2006 Jun 14 14 47 31 00 00 04 27kB LD LxT_Data 002 LD LxT_Data 003 LD LxT_Data 004 LD LxT_Data 005 LD LxT_Data 006 LD LxT_Data 007 LD LxT_Data 008 LD LxT_Data 009 Close Menu FIGURE 10 2 Data Explorer Using the CJ and lt gt keys you can scroll the list of data files As each file is selected you get an expanded view of the directory entry showing File name Description of measurement Start date and time of measurement End date and time of measurement Run time of measurement Data Explorer LxT Manual Menu Softkey LxT Manual Press the key to view the data file or press the Right Softkey labeled Menu for more options Data Explorer LD LxT_Data 001 Menu Delete Delete All Rename Save to USB Refresh List Load Settings LD LxT_Data 008 LD LGT Data 009 Close Menu FIGURE 10 3 Data Explorer
229. to the desired section and press the key to make a selection 4 14 Dosimeter 1 and 2 Pages LxT Manual OBA Max Spectrum Mode Note that the Max Spectrum data does not appear when making a basic sound level measurement It is only included here for completeness For more information on this feature see 1 1 and 1 3 Octave Spectra on page 9 2 OBA Time Averaging LxT Manual When using the Measurement History feature the user can select one of the following forms of the Max Spectrum to be measured and stored At Lmax Mode When the At Lmax mode has been selected the Max spectrum which is stored is the spectrum which was measured at the instant that the overall sound pressure level reached its maximum Bin Max Mode When the Bin Max mode has been selected each frequency band represents the largest value which occurred during the measurement interval Since the maximum levels for the frequency bands may have occurred at different times during the measurement this may not be a spectrum which actually existed Use the key to highlight the OBA Max Spectrum Mode data field and press the key to open the OBA Max Spectrum Mode Menu OBA Max Spectrum Mode FIGURE 4 13 OBA Max Spectrum Mode Menu Use the ED and C3 keys to move the highlight to the desired section and press the key to make a selection The time averaging used for the 1 1 and 1 3 octave frequency analysis depends upon the integration method s
230. to the display Exiting Measurement Property Screens LxT Manual Basic Data Display In the previous chapter the setup procedure for a basic sound level measurement was described This chapter describes how this data would be displayed during or following a measurement sequence The LxT can measure many additional sound parameters simultaneously with these basic sound measurements as described in subsequent chapters Data Labels The labels for sound metrics in the LxT are designated by international standards For many displayed values the frequency and time weighting are indicate in the name of the metric Example Las is the A weighted sound pressure level measured using the Slow detector Sound pressure level is often referred to as SPL Tabbed Page Structure Only a few of these horizontally Measured data are displayed using a number of tabbed pages arranged tab pages three in Figure arranged horizontally across the screen as shown in Figure 5 1 can be seen at one time To see 5 1 Depending on the firmware options loaded in the LxT those off screen to the right use the there may be as many as seven different data display pages Right Softkey beneath the display To in the Data Display Screen each identified by a title on a tab scroll back to the left use the Left at the top Softkey beneath the display LxT Manual Basic Data Display 5 1 Live Page 5 2 FIGURE 5 1 Tabbed Page Structure When the LxT is t
231. to the physical phenomenon of sound The descriptor should be used only when negative effects on people are known to occur Unfortunately this word is used also to describe sounds with no tonal content random Ambient The all encompassing sound at a given location caused by all sources of sound It is generally random but need not be Background The all encompassing sound at a given location caused by all sources of sound but excluding the source to be measured It is essentially the sound that interferes with a measurement Pink It is a random sound that maintains constant energy per octave Pink light is similar to pink noise in that it has a higher level at the lower frequencies red end of the spectrum White It is a random sound that contains equal energy at each frequency In this respect it is similar to white light It is the percentage of time a person is exposed to noise that is potentially damaging to hearing Zero represents no exposure and 100 or more represents complete exposure It is calculated by dividing the actual time of exposure by the allowed time of exposure The allowed time of exposure is determined by the Criterion Duration and by the sound level the higher the level the shorter the allowed time The sound levels must be measured with A frequency weighting and slow exponential time weighting See Projected Noise Dose where T is Measurement Duration T is Criteria Time Glossary D 15 Noise Ex
232. tomatically reset so a new measurement may begin Preferences 11 11 Store Jack Function The jack function setting becomes active as soon as it is selected 11 12 In this mode when the 22 STOP STORE key is pressed a data file is automatically saved The default file name is assigned to the file There is no user interaction in this process Pressing the 1 RUN PAUSE key the instrument will automatically reset so a new measurement may begin The AC DC Out Headset Jack on the bottom of the instrument can be configured to provide one of the following Asan AC DC output of the signal from the detector Use with the optional AC DC Output Cable CLBL139 AC signal is output via the red BNC and DC signal via the white BNC The AC output is typically directed to a frequency analyzer or oscilloscope and the DC output is typically directed to a strip chart recorder As a microphone and speaker connection when used with the optional headset for voice recording playback ACC003 It can also be set to Off Use the 7 and Z keys to highlight the Jack Function field and press the key to obtain a listing of the choices as shown in FIGURE 11 11 FIGURE 11 11 Jack Function Preferences Use the 7 and E keys to highlight the desired Jack Function press the key to make the selection Preferences LxT Manual USB Storage Reset Prompting Takt Maximal Data LxT Manual This can be used to cause data to be stored
233. topped Starting a New Measurement LxT Manual Otherwise press the O key to highlight Cancel and then the ENTER key to cancel both the Stop and the Reset operations After selecting to Stop the measurement the Save File Menu shown in FIGURE 7 9 Save File Menu on page 7 14 will appear to provide a choice of saving the measured data prior to the reset or not as described in Storing the Measurement on page 7 14 If the LxT is stopped when the D RESET key is pressed the Stop Required Menu will not appear but the Save File Menu will appear to provide a choice of saving the measured data prior to the reset or not After the reset has been performed the CR STOP STORE key will produce a steady red light to indicate the measurement state as Stopped Reset The Cay key RUN PAUSE key must be pressed to start a new measurement Keypad 3 9 TOOLS Key Note that there is one more icon System Utilities which does not appear in FIGURE 3 4 It is necessary to scroll down below the Lock and About icons in order to see it Pressing the A TOOLS key will bring you to the Control Panel screen Properties FIGURE 3 4 Control Panel Table 3 lindicates the chapter in which each of these functions is described Function Chapter Number Voice Recorder 8 Data Explorer 10 System Properties 11 Lock 12 Calibrate 13 About 14 System Utilities 15 Table 3 1 Chapters Describin
234. tware on page 1 12 5 15 8 The LxT uses no alternative dis play devices 5 16 1 AC DC Output Specifications on page A 5 and Jack Function on page 11 12 5 17 1 Control Page on page 4 16 and Time on page 11 3 5 17 1 NOTE 2 General Specifications on page A 4 5 17 2 Timed Stop Mode on page 6 4 5 18 1 Connectors and Interfaces on page 16 5 5 18 2 o AC Power and Radio Frequency Sus ceptibility on page B 13 5 19 1 The LxT is a single channel instrument LxT Manual Sections 5 6 7 and 9 except 9 3 Section LxT Manual Comments Microphone Extension Cable on page 7 6 and Use of a Windscreen on page 7 6 5 20 1 Power Indicator on page 3 2 5 20 2 Power Supply Specifications on page A 5 5 20 3 Power Supply Specifications on page A 5 and Internal Battery Operating Lifetime on page A 6 5 20 4 Table A 4 Power Supply Specifications on page 5 5 20 5 The LxT is not intended to be powered by a public source of AC power 6 1 2 l Typical Stabilization Time on page B 12 6 2 2 Calibrating The LxT on page 13 7 6 5 2 General Specifications on page A 4 6 6 1 o AC Power and Radio Frequency Sus ceptibility on page B 13 6 6 3 No detectable increase in any direction with application of 74 dB A weighted sound level 6 6 9 0 AC Power and Radio Frequency Sus ceptibility on page B 13 7 1 Microphone Extension Cable
235. uct improvement specifications are subject to change without notice Larson Davis provides a complete line of acoustic measurement tools including dosimeters sound level meters real time analyzers preamps calibrators and microphones LxT Manual Technical Specifications A 49 O Preamplifier Model PRMLxT2L Serial Number 0104 Larson D vis Certificate of Electrical Conformance Frequency response of this model PRMLxT2L preamplifier was tested at a level of 1 157 Vrms with 18pF microphone capacitance and driving a short cable Output level at 1kHz is 1 0018 Vrms 0 016 dBV uncertainty 0 035 dB Output is 3 586 V DC uncertainty 0 001 Results are displayed relative to the level at 1kHz 0 5 50 100 200 501 1000 1995 5012 10000 19953 50000 100000 Frequency Hz Measured dB Uncert dB Tolerance dB Freq Hz Measured dB Uncert dB Tolerance dB 16 0 51 058 0 32 0 73 794 33 00 016 0 10 0 10 EI 0 35 058 0 22 0 50 1000 00 00 016 0 10 0 10 01 0 23 036 0 12 0 36 1258 90 00 016 0 10 0 10 EN 0 16 036 0 04 0 28 1584 90 00 016 0 10 0 10 94 0 11 036 0 01 0 21 1995 30 00 016 0 10 0 10 00 0 07 016 0 03 0 17 2511 90 00 016 0 10 0 10 59 0 05 016 0 05 0 15 3162 30 00 016 0 10 0 10 BER 0 04 016 0 06 0 14 3981 10 01 016 0 10 0 10 95 0 03 016 0 07 0 13 5011 90
236. uld help for example 100 000 would be equal to 50 and 1000 would be Glossary LxT Manual LxT Manual equal to 30 and so on This is the basic principal of the dB measure All dB values are unit free and therefore the dB value is not the value of the quantity itself but the ratio of that quantity to an actual reference quantity used Thus for every level in decibels there must be a well defined reference quantity Sound versus vibration uses different references but the dB principal is the same When the quantity equals the reference quantity the level is zero To keep dB values above zero the reference is generally set to be the lowest value of the quantity that we can imagine or normally wish to use Before explaining the calculation of dB values it is useful to remember the following rules of thumb when dB values are used for sound levels Doubling of the Sound Pressure 6 dB Doubling of the Sound Power 3 dB Doubling of the Perceived Sound Level approx 10 dB Note The latter is frequency and level dependent but the value 10 dB is a good rule of thumb especially around 1 kHz Table 1 shows the actual value of a specific item such as sound power for which the sound level is calculated First the sound power value is divided with the reference used and then the ten based logarithm is applied This value is then multiplied by 10 to create the decibel value see equation D 1 below For every 10 decibel
237. und power If we consider sound pressure levels instead usually denoted P in acoustics the equation will be the same since the two in the squared units will move from within the bracket and become a 20 log instead of a 0 Jog and thus compensate for using linear or quadratic units Please note that it is not allowed to use 20 log for squared units since that expression assumes that we use linear units like sound pressure in acoustics or voltage in electrical engineering This is illustrated in equation D 1 below Glossary LxT Manual 2 dB 10Log 5 20Lo8 gt Po 20uPa Po Po Table 2 illustrates how a a tenfold increase of the sound pressure will result in an increase in 20 dB steps while sound power increases in 10 dB steps See the linear form Table 2 and compare with equation D 1 In conclusion dB values are always the same independent of using sound power or sound pressure as the base unit A 6 dB increase implies four times the sound power or two times the sound pressure Linear form non squared units Level form i Exponential Form of 20 Exponent Ration of Value to Reference p Ratio 1 10 0 10 10 20 100 10 40 200 107 46 1 000 10 60 10 000 10 80 100 000 10 100 1000 000 10 120 Department of Defense Level Lpop Dose Detector LxT Manual The Average Sound Level calculated in accordance with Department of Defense Exchange Rate and Threshold Leve
238. ure Metrics Measured the symbol X is used to represent the user selected RMS and Impulse frequency weighting A C or Z and the symbol Y is used to represent the user selected peak frequency weighting A C or Z 17 4 Sound Exposure Metrics Measured LxT Manual The symbol V is used to represent the user selected time weighting F S or I Metric Symbol Sound Exposure Level SEL Lxve Average Sound Level Lavg Lxavg Time Weighted Average Level TWA x TWAQ Noise Dose DOSE Projected Noise Dose Daily Personal Noise Exposure Lep d ProjDose Sound Exposure E Projected 8 Hour Sound Exposure Projected 40 Hour Sound Exposure SEA Table 17 2 Sound Exposure Metrics Measured Statistical Metrics Measured See Ln Page on page 4 12 Exceedance Counters See Triggers Page on page 4 20 Six Ln statistical parameters are measured using the frequency weighting A C or Z and exponential averaging Slow or Fast selected when setting up the LxT for a sound level measurement These six values are user selected over the range Lan to Log 99 The LxT has three exceedance event counters two RMS event counters and three peak event counters For each exceedance there is a threshold level event counter and duration The thresholds L or L are the levels that the XV Ypeak parameter must exceed to increment the counter and LxT Manual Statistical Metrics Measured 17 5 duration
239. urned ON the user is presented with the Live Page The measurements displayed on the Live Page are always active real time measurements The displayed values are not controlled by the Ei RUN PAUSE key This allows you to view the current SPL without disrupting any overall data For example suppose you are making a measurement and an unwanted event takes place causing you to stop the measurement With the measurement stopped you can monitor the actual level on the Live Page to be certain that the residue effects of the unwanted event have died down before beginning a new measurement There are five sections to the Live Page To scroll between sections use the CI or keys The Right and Left Softkeys beneath the display scroll between pages Live Page LxT Manual Sound Level Profile Note that the graph scaling can be modified as described in section Adjust Graph Scale on page 5 23 LxT Manual lt gt 0 00 46 9 E LxT_Data Live EAS TA Laeq 1s 49 2 dB EZ Las 48 1 dB LZpeak Started 2006 Jun 05 16 32 51 FIGURE 5 2 Live Page Section 1 Section 1 presents a recent history of Lagg calculated for each second The graph presents the last 120 seconds of the measurement The La eg 15 is the numeric presentation of the most recently graphed 1 second value The Lag is the instantaneous measured level from the RMS detector The Lzpeak is the current measurement from the 1 s peak detector The time
240. using the LxT Utility software LxT Manual press the key to obtain the display shown in Figure 9 16 gt 0 00 35 3 i Wb Markers View O1 5 6 10 Close FIGURE 9 16 Markers Setup Window Markers 6 10 To name a marker use the 5 and C keys to highlight the field of the marker to be named and press the key This will produce a cursor which can be moved left and right to different digit positions in the data field using the and keys as shown in Figure 9 17 1 5 06 10 FIGURE 9 17 Marker Name Field At any horizontal position use the 3I and CH keys to select a an alphanumeric character When the desired name has been entered press the key to conclude the process Markers 9 19 Using Markers Setting Markers On Off 9 20 The Time History page of the Data Display View is used to display the data as shown in FIGURE 9 5 Time History Display First Point Keypress Beginning Measurement Before or after the measurement is begun press the Menu softkey to bring up the display shown in Figure 9 18 Settings Mark Sound Type Adjust Graph FIGURE 9 18 Menu Options Use the key to highlight Mark Sound Type and press the key which will modify the Time History display as shown in Figure 9 19 TT Motorcycle C Aircraft C Exclude O 6 FIGURE 9 19 Time History Display with Markers At any time during a measurement any of the markers can be set On or Off Use the gt and
241. valent Electrical Impedance Adaptor Cables LxT Manual An equivalent electrical impedance adapter can be used in place of the microphone when the instrument is being measured electrically The adapter is simply a series capacitor with the same capacitance as the microphone it is replacing The following adapters will be available for sale e ADP002 6 8pF Adaptor for 1 4 in 7pF microphone 377B01 e ADP005 18pF for 1 2 in 18pF microphone 7052 Direct Input Cable or Adaptor e Microphone Extension Cable EXCXXX where XXX is the length in feet XXX 010 020 050 066 100 and 200 available e USB Cable CBL138 e AC DC Output Cable CBL139 e Universal AC Power Adaptor PSA029 Features 1 11 Software Other 1 12 Blaze software SWW_BLAZE_LXT for setup control and high speed data download DNA Data Navigation and Analysis software for instrument control high speed data download data streaming with real time data display on PC advanced data graphic presentations and powerful report generation features Headset with microphone for voice recording playback LXT HS Note this is included with the optional accessory LXT DVA Storage Case LXT CCS Tripods TRP001 Instrument Camera Tripod with ADP032 1 2 in microphone clip TRP002 Microphone Stand with adjustable height and boom angle Calibrators CAL150 CAL200 Features LxT Manual LxT Components gt Microphone Preamplifier
242. y lt 0 05 dB from 0 to 90 RH non condensing at 40 C 104 F Dimensions 2 7 mm diameter x 125 mm length 0 50 dia x 4 92 length Microphone Thread 11 7 mm 60 UNS 0 4606 60 UNS LxT Manual Technical Specifications A 47 Cable Driving Capability LxT SLM 1 V rms output signal To 20 kHz with 200 60 m cable All values are at 23 C 50 RH 7 5 Volt supply 3 m 10 cable and equivalent microphone of 18pF unless otherwise stated Output Connector Switchcraft TA5M 5 Pin male Pin Signal 1 Signal Ground 2 Signal Output 3 Power Supply 7 Volts 4 Preamp sense 5 No Connection Shell Connect to preamp housing Table A 24 Input Connector Compatibility Use with ACO 7052 or any 4 electret microphone having about 20 mV Pa sensitivity and meeting the mechanical requirements of IEC 61094 4 It can be used with either the Larson Davis ADP043 or ADP008 adapters for 1 4 or 1 electret microphones A 48 Technical Specifications LxT Manual Optional Accessories EXCXXX Extension Cable 5 Pin Switchcraft male to 5 Pin Switchcraft female XXX feet long ADP005 18 pF equivalent Y Microphone with BNC Connector input ADP008 Adapter for 1 microphones ADP040 Microphone Signal Tee ADP043 Adapter for 1 4 microphones ADP068 Preamplifier holder for 2 preamplifiers on microphone stand Table A 25 Optional Accessories In the interest of constant prod
243. z dB dB dB dB dB 251 19 0 0 0 0 0 0 0 0 0 0 316 23 0 1 0 1 0 0 0 1 0 1 398 11 0 1 0 1 0 1 0 0 0 0 501 19 0 0 0 0 0 1 0 1 0 1 630 96 0 0 0 0 0 1 0 1 0 1 794 33 0 1 0 1 0 0 0 1 0 1 1000 00 0 2 0 2 0 1 0 1 0 1 1059 25 0 2 0 2 0 1 0 1 0 1 1122 02 0 3 0 3 0 2 0 1 0 1 1188 50 0 4 0 4 0 2 0 2 0 2 1258 93 0 4 0 4 0 3 0 1 0 1 1333 52 0 4 0 4 0 3 0 1 0 1 1412 54 0 3 0 3 0 2 0 1 0 1 1496 24 0 4 0 4 0 3 0 1 0 1 1584 89 0 2 0 2 0 2 0 0 0 0 1678 80 0 3 0 3 0 3 0 0 0 0 1778 28 0 1 0 1 0 3 0 2 0 2 1883 65 0 1 0 1 0 3 0 2 0 2 1995 26 0 1 0 1 0 4 0 5 0 5 2113 49 0 2 0 2 0 4 0 6 0 6 2238 72 0 2 0 2 0 4 0 6 0 6 2371 37 0 0 0 0 0 5 0 5 0 5 2511 89 0 0 0 0 0 4 0 4 0 4 2660 73 0 0 0 0 0 5 0 5 0 5 2818 38 0 1 0 1 0 4 0 5 0 5 2985 38 0 3 0 3 0 5 0 2 0 2 3162 28 4 2 0 2 0 3 0 1 0 1 3349 65 0 3 0 3 0 2 0 1 0 1 3548 13 0 6 0 6 0 2 0 4 0 4 3758 37 0 3 0 3 0 1 0 2 0 2 3981 07 0 1 0 1 0 1 0 2 0 2 4216 97 0 2 0 2 0 1 0 3 0 3 4466 84 0 0 0 0 0 1 0 1 0 1 4731 51 0 0 0 0 0 3 0 3 0 3 Continued on next page B 14 LxT2 LxT Manual 5011 87 0 2 0 2 0 4 0 6 0 6 0 6 5308 84 0 0 0 0 0 5 0 5 0 5 0 6 5623 41 0 3 0 3 4 3 0 6 0 6 0 6 5956 62 0 4 0 4 0 2 0 2 0 2 0 6 6309 57 0 0 0 0 0 3 0 3 0 3 0 6 6683 44 0 1 0 1 0 1 0 0 0 0 0 6 7079 46 0 2 0 2 0 1 0 3 0 3 0 6 7498 94 0 4 0 4 0 2 0 6 0 6 0 6 7943 28 0 5 0 5 0 2 0 7 0 7 0 6 8413 95 0 5 0 5 0 3 0 8 0 8 0 6 8912 51 1 0 1 0 0 7 1 7 1 7 0 6 9440 61

LxT User Manual.book - Pegasus Consultores SAC

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