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PSM1735-User-manual

1. shunt value purpose normal 1000 general purpose all frequencies high 10kQ higher impedance low to medium frequency very high 1MQ impedance gt 100kQ low frequency only Ensure the LCR Active Head option is enabled in the AUX menu The active head contains high impedance buffer amplifiers that help to reduce the effect of stray capacitance and inductance The active head is usually supplied with Kelvin clip leads but Kelvin test probes are also available for in circuit testing Part numbers 500 056 LCR active head 510 013 Kelvin clip lead set 510 014 Kelvin test probe set A 4 PSM1735 NumetriQ user manual Transformer analyser fixture TAFO1 The transformer analyser fixture TAFO1 consists of a relay switching base unit that accepts plug in module to interface to transformers It connects to the BNC connectors on the front of NumetriQ and is controlled by NumetriQ via the extension port It supports transformers with 2 single windings or with 1 single winding and one split winding The winding s to be used for a measurement may be controlled by the front panel or by communications The connections to the transformer may be made either by a plug in pcb with suitable ZIF socket and resistors or by flying leads with cable clips To use the latter plug in a resistance carrier board with appropriate source and load resistors NB it is essential that a source resistor be fitted for
2. The high linearity of NumetriQ allows real time measurements be made on waveforms with periodic bursts such as low standby power PSUs Use autorange up to find the range NumetriQ blanks the results when either of the measured rms signals are low compared to the full scale range This function can be disabled if desired in the SYSTEM menu The ZOOM function can be used to select any combination of up to four parameters from the display The integrator is started or reset by pressing the START key The Watt hour integration and the Ampere hour integration can be selected to be signed or magnitude To integrate the total power in terms of heating effect choose magnitude If signed integration is selected then the rms current is given the sign of the power before integration The Ampere hours and Watt hours then reflect the power 13 3 PSM1735 NumetriQ user manual taken by the load less any power generated by the load such as during regenerative braking in battery systems PSM1735 NumetriQ user manual 13 1 Power meter specification current input external shunt display 5 digits measurement W VA PF fundamental rms phase coupling ac or ac dc frequency dc to 1MHz 1MHz to 35MHz fundamentals only ac coupling cut off 1 5Hz 3dB max input 10V peak input ranges 10V 3V 1V 300mV 100mV 30mV 10mV 3mV 1mV ranging full auto up only or manual input impedance 1M 30pF exc leads accuracy ac 0 15 rang
3. 10 True RMS Voltmeter The RMS voltmeter measures the total rms of the signal present at the input terminals to the bandwidth of the instrument gt 1MHz Care must be taken when measuring low signal levels to minimise noise pick on the input leads The RMS voltmeter measures the elementary values rms dc peak surge and derives the values ac dBm and crest factor The rms value of a periodic waveform v 6 is given by 27 rms y 1 27 v 4 d 0 For a sampled signal the formula becomes i n 1 rms y 1 n vi i 0 where n is the number of samples for an integral number of complete cycles of the input waveform These are fundamental definitions that are valid for all waveshapes For a pure sinewave the formulae equate to peak V2 but this cannot be applied to other waveshapes NumetriQ computes the true rms value from the fundamental definition for sampled data 10 1 PSM1735 NumetriQ user manual The dc present is given by 27 dc 1 21 v 6 de 0 For a sampled signal the formula becomes i n l dec 1 n Y vii i 0 where n is the number of samples for an integral number of complete cycles of the input waveform Having computed the true rms and the dc component the ac component can be derived from rms ac de gt ac rms de The ac component is also expressed in dB referred to 1mW into 6000 dBm dBm 20 log Vac Vref where Vref Y 1mW x 6000 or
4. frequency locations used memory points in sweep per sweep capacity up to 50 1 30 51 100 2 15 101 150 3 10 151 200 4 7 201 250 5 6 251 500 8 3 501 1000 15 2 1001 2000 30 1 When storing a sweep a text string may be entered to help identify the data Each stored sweep also saves the instrument configuration along with the sweep results same as program store recall so that the instrument is restored to the same settings when the sweep is recalled The sweep data may be restored manually or via communications for download to a PC To manually access the sweep data store press PROG and select memory type sweep 4 9 PSM1735 NumetriQ user manual 5 Using remote control NumetriQ is fitted with an RS232 serial communications port as standard and may have an IEEE483 GPIB interface or LAN interface fitted as an option All the interfaces use the same ASCII protocol with the exception of the end of line terminators Rx expects Tx sends RS232 Carriage return carriage return line feed ignored and line feed LAN carriage return carriage return line feed ignored and line feed IEEE488 Carriage return or carriage return line feed or EOI with EOI All the functions of the NumetriQ can be programmed via either interface and results read back When the IEEE483 interface is set to remote the RS232 port is ignored The commands are not case sensitive and white space
5. 5 3 PSM1735 NumetriQ user manual 5 2 Serial Poll status byte ESB MAV FDV SDV RDV bit 0 RDV result data available set when results are available to be read as enabled by DAVER bit 1 SDV sweep data available set when sweep results are available to be read as enabled by DAVER bit2 FDV fast data available streaming set when data streaming results are available to be read as enabled by DAVER bit 4 MAV message available set when a message reply is waiting to be read bit 5 ESB standard event summary bit 5 4 set if any bit in the standard event status register is set as well as the corresponding bit in the standard event status enable register set by ESE PSM1735 NumetriQ user manual 5 3 RS232 connections The RS232 port on NumetriQ uses the same pinout as a standard 9 pin serial port on a PC or laptop 9 pin male D type Pin Function Direction 1 DCD in weak pull up 2 RX data in 3 TX data out 4 DTR out 5 GND 6 DSR not used 7 RTS out 8 CTS in 9 RI not used NumetriQ will only transmit when CTS pin 8 is asserted and can only receive if DCD pin 1 is asserted NumetriQ constantly asserts 12V DTR pin 4 so this pin can be connected to any unwanted modem control inputs to force operation without handshaking NumetriQ has a weak pull up on pin 1 as many null modem cables leave it open circuit In electrically noisy environments this pin should
6. Accordingly this manual first describes the general features and specification of the instrument as a whole and then describes the individual functions in detail Each function is described in turn in its own chapter with details of the principles on which it is based how to use it the options available display options specifications etc Detailed descriptions of the RS232 command set is given in the separate manual PSM17xx communications manual Revision 1 48 This manual is copyright O 2005 2009 Newtons4th Ltd and all rights are reserved No part may be copied or reproduced in any form without prior written consent 10 February 2010 PSM1735 NumetriQ user manual CONTENTS 1 Introduction general principles of operation 1 1 1 1 Generator output ah 1 3 1 2 Voltage inputs la 1 4 2 Getting SEAL OO tucan dels da 2 1 2 1 Unai cat asada 2 1 2 2 Keyboard and controls ssssssssssessssrrrrrrrrrrrrrrrersse 2 3 2 3 Basic perati N iS 2 4 3 Using the MEUS cds 3 1 3 1 Selection from a SE ea aa 3 3 3 2 Numeric data entry ii rain 3 4 3 3 TOLLE Yan ana 3 5 4 Special functions as 4 1 4 1 DIS DAY ZOO EN erea opino dorar naar ae ae era AR AEAT EA DENTAN 4 1 4 2 Program store and recall uzssessseenennnnenennnnen nennen 4 2 4 3 Zero compens tion zzsssssenennnnenennnnennnnnnnnnn nennen 4 3 4 4 Alarmi TUN CO Misas kk a ER 4 4 4 5 Analogue output nn 4 6 4 6 Data Roldan SS a 4 7 4 7 Parallel
7. EN 61326 1997 Class A 73 23 EEC relating to safety of laboratory equipment EN 61010 1 January 2005 Eur Ing Allan Winsor BSc CEng MIEE Director Newtons4th Ltd PSM1735 NumetriQ user manual WARRANTY This product is guaranteed to be free from defects in materials and workmanship for a period of 36 months from the date of purchase In the unlikely event of any problem within this guarantee period first contact Newtons4th Ltd or your local representative to give a description of the problem Please have as much relevant information to hand as possible particularly the serial number and release numbers press SYSTEM then LEFT If the problem cannot be resolved directly then you will be given an RMA number and asked to return the unit The unit will be repaired or replaced at the sole discretion of Newtons4th Ltd This guarantee is limited to the cost of the NumetriQ itself and does not extend to any consequential damage or losses whatsoever including but not limited to any loss of earnings arising from a failure of the product or software In the event of any problem with the instrument outside of the guarantee period Newtons4th Ltd offers a full repair and re calibration service contact your local representative It is recommended that NumetriQ be re calibrated annually ABOUT THIS MANUAL NumetriQ has of number of separate measurement functions that share common resources such as the keyboard and display
8. Flow control is RTS CTS see section 5 2 baud rate is selectable via the MONITOR menu A summary of the available commands is given in the Appendix Details of each command are given in the communication command section of the manual Commands are executed in sequence except for two special characters that are immediately obeyed Control T 20 reset interface device clear Control U 21 warm restart To maintain compatibility with some communication systems there is an optional protocol 2 which requires a space between the command and any arguments 5 2 PSM1735 NumetriQ user manual 5 1 Standard event status register PON CME EXE DDE QYE OPC bit O OPC operation complete cleared by most commands set when data available or sweep complete bit 2 QYE unterminated query error set if no message ready when data read bit 3 DDE device dependent error set when the instrument has an error bit 4 EXE execution error set when the command cannot be executed bit 5 CME command interpretation error set when a command has not been recognised bit 7 PON power on event set when power first applied or unit has reset The bits in the standard event status register except for OPC are set by the relevant event and cleared by specific command ESR CLS RST OPC is also cleared by most commands that change any part of the configuration of the instrument such as MODE or START
9. Port en Br 4 8 4 8 Sweep results store and recall cccceeeeeeeeeeeeae eres 4 9 5 Using remote control aiii is a 5 1 5 1 Standard event status registeT ooooccccccccocccconnccnnncnnos 5 3 5 2 Serial Poll status byte can nen 5 4 5 3 RS232 Connections ann 5 5 5 4 Bata streaming ul 5 6 System Options Ar ee sad a 6 1 6 1 User data dad 6 3 7 Measurement Options cccccecceceeeeseeeeeeeseanees 7 1 7 1 ACQU ACQUISITION OPTIONS ccc cece eeee cent essen nennen 7 1 7 2 LB risene O A EN EDR ES 7 4 7 3 SWEEP Frequency sweep options ococccccccconcccnnncnnoo 7 6 7 4 TRIM Trim function sta dl 7 8 87 OUDULCONEFO narrar do 8 1 8 1 Generator specificatiONS oococccccnccocnnconnnconnnnonnanons 8 3 97 LABUE Channels ee eds 9 1 9 1 Trimming x10 oscilloscope PrObeS cccceee cence eene ees 9 5 10 True RMS Voltmeter ccccceeeeeseeeeeeeeseeeees 10 1 10 1 RMS voltmeter specification unsssensseenenennenen een 10 4 11 Frequency response analyser cceceeeee cece ee eee es 11 1 11 1 Frequency response analyser specification 11 5 12 Phase angle voltmeter vector voltmeter 12 1 12 1 Phase angle voltmeter specification 12 4 13 Power Meter ae ia Uca 13 1 13 1 Power meter specification ococcococcccocnnconnnconnnnnas 13 5 14 LCRAM OL Ha 14 1 14 1 LCR meter specification oococcccccnconcnconnncnnnanannnnnos 14 7 15 Harmonic analyser ans en
10. and a heterodyning technique to give high accuracy at high frequencies The NumetriQ has two processors a DSP digital signal processor for data analysis a CPU central processing unit for control and display At the heart of the system is an FPGA field programmable gate array that interfaces the various elements our Ef CPU CH1 LASS FPGA A CH2 G 7 Fr DSP This general purpose structure provides a versatile hardware platform that can be configured by firmware to provide a variety of test functions including 1 1 signal generator two channel true rms voltmeter phase angle voltmeter vector voltmeter frequency response analyser gain phase analyser harmonic analyser With additional external interfaces such as current shunts other functions are possible true rms current meter LCR meter power meter NumetriQ is configured to perform the required test function by simple user menus or can be controlled remotely via a serial interface RS232 or optionally LAN interface or GPIB interface The programmable nature of the instrument means that new functions can be added as they become available or existing functions can be enhanced by simple firmware download 1 2 PSM1735 NumetriQ user manual 1 1 Generator output The output sinewave is generated by direct digital synthesis DDS Amplitude is set in 2 stages a fine control
11. characters are ignored e g tabs and spaces Replies from NumetriQ are always upper case delimited by commas without spaces Only the first six characters of any command are important any further characters will be ignored For example the command to set the generator frequency is FREQUE but the full word FREQUENCY may be sent as the redundant NCY at the end will be ignored Fields within a command are delimited by comma multiple commands can be sent on one line delimited with a semi colon eg AMPLIT 1 5 OUTPUT ON Mandatory commands specified in the IEEE488 2 protocol have been implemented e g IDN RST and all 5 1 PSM1735 NumetriQ user manual commands that expect a reply are terminated with a question mark NumetriQ maintains an error status byte consistent with the requirements of the 1EEE488 2 protocol called the standard event status register that can be read by the mandatory command ESR see section 5 1 NumetriQ also maintains a status byte consistent with the requirements of the IEEE488 2 protocol that can be read either with the IEEE488 serial poll function or by the mandatory command STB over RS232 or IEEE or LAN see section 5 2 The IEEE address defaults to 23 and can be changed via the COMMS menu The keyboard is disabled when the instrument is set to remote using the IEEE Press HOME to return to local RS232 data format is start bit 8 data bits no parity 1 stop bit
12. consultar con su suministrador PSM1735 NumetriQ user manual IMPORTANT SAFETY INSTRUCTIONS This equipment is designed to comply with BSEN 61010 1 Safety requirements for electrical equipment for measurement control and laboratory use observe the following precautions e Ensure that the supply voltage agrees with the rating of the instrument printed on the back panel before connecting the mains cord to the supply e This appliance must be earthed Ensure that the instrument is powered from a properly grounded supply e The inputs must not be connected to signals greater than 10V peak e Keep the ventilation holes on the underneath and sides free from obstruction e Do not operate or store under conditions where condensation may occur or where conducting debris may enter the case e There are no user serviceable parts inside the instrument do not attempt to open the instrument refer service to the manufacturer or his appointed agent Note Newtons4th Ltd shall not be liable for any consequential damages losses costs or expenses arising from the use or misuse of this product however caused DECLARATION OF CONFORMITY Manufacturer Newtons4th Ltd Address 1 Bede Island Road Leicester LE2 7EA We declare that the product Description Phase Sensitive Multimeter Product name NumetriQ Model PSM1735 Conforms to the requirements of Council Directives 89 336 EEC relating to electromagnetic compatibility
13. external source measurement type DFT analysis true rms as appropriate measurements turns ratio turns inductance leakage inductance ac resistance dc resistance interwinding capacitance insertion loss return loss harmonics thd longitudinal balance conditions auto or manual display numeric values table of sweep results graph of any measurement accuracy refer to other functions sweep capability all ac functions sweep step rate 1 20s 1 3s or 2 55 approx 16 13 PSM1735 NumetriQ user manual Appendix A Accessories ACCESSORIES PSM1735 NumetriQ user manual Power meter adaptors The power meter adaptors allow easy and safe connection of the NumetriQ to a mains appliance under test to measure the power or harmonics The appliance under test plugs into an IEC mains outlet on the adaptor which contains an isolating voltage transformer and current transformer with precision low resistance shunt The adaptor is fitted with an IEC mains inlet for use with an appropriate mains lead When the adaptor is plugged into the mains and the mains switched on the appliance is energised and NumetriQ can be used to measure the power or harmonics Leave the NumetriQ generator off OUT menu so that it will synchronise to the mains frequency Part numbers 500 058 IEC 10A power meter adaptor A 2 PSM1735 NumetriQ user manual 750 6000 output adapter The generator output from the NumetriQ has a se
14. 15 1 15 1 Harmonic analyser specification cccceeeeee eee eee 15 4 16 Transformer analyser cc cccceceeee cece onen nenn 16 1 16 1 BUMS A See E ade SENSE Sr 16 3 16 2 Inductance leakage inductance cccc cece eee ees 16 4 16 3 AC resistance and Q factor ccc cece cceceeeeeeeeseeeeeeeees 16 5 16 4 DETESIsante nem 16 5 16 5 Interwinding CAPACITANCE ccc cece cece eee ee eeeeeeneeeeas 16 6 16 6 MagnetiSing current esssssssensenenennennnnnnnnennenen nn 16 7 A A ER En noe a i a a iaa 16 8 16 8 Insertion LOSS 2 ie dtl tienda Oe eee abate nee 16 9 16 9 Harmonics and distortion ersssssssen nenn nenn nenn nenn 16 11 16 10 Longitudinal balance uz22sss220nnenon nenn nennen 16 12 vi PSM1735 NumetriQ user manual APPENDICES Appendix A Accessories Appendix B Serial command summary Appendix C Available character set Appendix D Configurable parameters Appendix E Contact details vil PSM1735 NumetriQ user manual 1 Introduction general principles of operation NumetriQ is a self contained test instrument with one output and two inputs which incorporates a suite of test functions NumetriQ has a wide bandwidth generator output that can be used as signal generator for sine or square waveforms A dc offset may be added to the signal generator output NumetriQ has two differential high bandwidth voltage inputs which use direct digital analysis at low frequencies
15. 20 log lac l ref where Iref Y 1mW 6000 The peak measurement is simply the value with the largest magnitude Positive and negative peaks are independently filtered then the result with the largest magnitude is taken as the peak value In order to measure surge conditions the maximum instantaneous peak value unfiltered is also recorded It is 10 2 PSM1735 NumetriQ user manual important that NumetriQ does not autorange while measuring surge either set the range to manual or repeat the test with ranging set to up only To reset the maximum press START Crest factor is derived from the peak and rms cf peak rms The measurements are computed over rectangular windows with no gaps The processing power of the DSP allows the measurements to be made in real time without missing any samples In this way the measured rms is a true value even if the signal is fluctuating The only occasion when data is missed is when an autozero measurement is requested this can be disabled in the SYTEM OPTIONS menu if required The ZOOM function can be used to select any combination of up to four parameters from the display Note that the wideband nature of true rms measurements prevents the use of heterodyning so the frequency range of the measurement is limited to 1MHz To minimise noise there is a 50kHz filter applied by default To obtain the full bandwidth press ACQU highlight bandwidth and select wide 10 3 PSM1735
16. NumetriQ user manual 10 1 RMS voltmeter specification channels display measurement coupling frequency ac coupling cut off max input input ranges ranging input impedance accuracy ac accuracy dc CMRR typical time constant Conditions 2 differential 5 digits true rms ac dc dBm peak cf surge ac or ac dc dc to IMHz heterodyning not available 1 5Hz 3dB 10V peak 10V 3V 1V 300mV 100mV 30mV 10mV 3mV 1mV full auto up only or manual 1M 30pF exc leads 0 05 range 0 05 reading 0 1mV lt 1kHz 0 05 range 0 05 reading 0 001 kHz 0 1mV lt 10kHz 0 05 range 0 05 reading 0 002 kHz 0 1mV lt 1MHz 0 1 range 0 1 reading 0 5mV 60dB 10V 50Hz 50dB 10V 1kHz 40dB 10V 1MHz 0 2s 1 5s or 12s 23 C 5 C ambient temperature instrument allowed to warm up for 230 minutes sinewave slow speed normal filtering ac dc coupling autoranging or manual ranging gt 1 3 range PSM1735 NumetriQ user manual 11 Frequency response analyser NumetriQ measures the gain and phase of channel 2 relative to channel 1 using a discrete Fourier transform DFT algorithm at the fundamental frequency The DFT technique can measure phase as well as magnitude and is inherently good at rejecting noise it is much more reliable than measuring the rms at one point relative to another point The circuit can be characterised by computing the gain and phase at
17. all tests The fixture contains high impedance buffer amplifiers that help to reduce the effect of stray capacitance and inductance Part numbers 500 017 TAFO1 transformer analyser fixture 500 019 plug in module for modem transformers 500 020 plug in module for longitudinal balance 500 021 plug in resistance carrier 500 044 plug in terminal block module 510 015 TAFO1 Kelvin lead set 509 004 UK mains PSU A 5 PSM1735 NumetriQ user manual Injection transformer When testing the stability of control loops it is necessary to inject a small disturbance signal into the loop NumetriQ output is ground referenced so it is necessary to isolate the output before it can be connected to the loop The standard injection transformer provides an isolated output at a reduced signal level of about 1 6 of the direct output level over a frequency range of about 10Hz to 200kHz The high frequency injection transformer operates over a frequency range from 1kHz to 25MHz Connections are via BNC connectors one is grounded to the case the other is isolated The grounded connector should be connected to the OUTPUT connector of NumetriQ the isolated connector should be wired to the circuit under test Part numbers 500 042 standard injection transformer 500 047 High frequency injection transformer 500 048 High Voltage injection transformer 500 070 Low frequency injection module A 6 PSM1735 NumetriQ user manual CommVIE
18. be driven or connected to pin 4 To connect NumetriQ to a PC use a 9 pin female to 9 pin female null modem cable 1 amp 6 4 2 3 3 2 4 1 amp 6 5 5 7 8 8 7 5 5 PSM1735 NumetriQ user manual 5 4 Data streaming The phase angle voltmeter and power meter modes have the option of high speed data streaming In this operation the window width for the measurement may be specified from 660us to 100ms and the data for each measurement window is transmitted over the communications in a continuous stream The window is adjusted to synchronise to the measured frequency NumetriQ buffers the data and transmits at the fastest rate that is possible The buffer depth is over 8000 data values so more than 5 seconds of data can be captured at the fastest rate of 1500 readings per second even if the data is not read at all If the window size is such that the data can be read out in real time then data streaming can continue indefinitely Once the data streaming window has been setup but before the streaming has been started the display periodically shows the measured value Once streaming has been started the display is blanked to minimise processing overheads Streaming can be stopped either immediately ABORT or may be stopped but remaining data continues to be transmitted until the buffer is empty STOP STREAM ENABLE 0 01 START read data STOP continue to read stored data 5 6 PSM1735 NumetriQ user manual
19. easiest way to connect to the transformer in the various configurations for the different test is to use the transformer analyser fixture see accessories that connects to the NumetriQ BNC connectors via the BNC splitters and also to the NumetriQ extension port Using the fixture with appropriate source and load resistors the test configuration and winding selection is selectable from the front panel Active buffers within the fixture minimise the effects of stray capacitance and inductance For higher frequency operation or if the automatic fixture is not available make the connections manually with x10 oscilloscope probes set the fixture option in the AUX menu to none 16 1 PSM1735 NumetriQ user manual The operating conditions for the component under test may be selected manually or for some tests such as turns ratio NumetriQ will automatically try to find appropriate conditions NumetriQ can operate either in real time mode at a single frequency where the measurements are filtered and updated on the display or it can sweep a range of frequencies and present the results as a table or graphs Before performing a sweep the required test must be selected The ZOOM function can be used to select up to four parameters from the display when in real time mode It has no function following a sweep Although it is most usual to use the NumetriQ generator when performing transformer analysis there may be circumstances where
20. of steps Note that due to compound multiplication it is unlikely that the end frequency will be exactly that programmed The frequency sweep is initiated by the START key and when completed the data can be viewed as a table or graphs or printed out The window over which the measurements are computed is adjusted to give an integral number of cycles of the input waveform In real time mode the results from each window are passed through a digital filter equivalent to a first order RC low pass filter in sweep mode each result comprises a single window without any filtering unless repeat sweep is selected Very good results can be obtained in a reasonable time using the medium speed setting e g 50 points x 1 3s 17s for the very best results use the slow setting 50 points x 2 5s 125s or 2 minutes 5 seconds 14 5 PSM1735 NumetriQ user manual The ZOOM function can be used to select up to four parameters from the display when in real time mode It has no function following a sweep Although it is most usual to use the NumetriQ generator when performing LCR measurements there may be circumstances where this is impractical for example measuring the inductance of a transformer primary winding under load In this case turn off the NumetriQ generator OUT menu and the frequency reference for the analysis is measured from channel 1 Provided that the signal is clean enough for an accurate frequency measurement and for DFT an
21. ok data data data data data freq magl1 mag2 dB phase n lines of GAINPH data freq magl1 mag2 parameter n lines of TXA data 3 CR terminated text strings freq magl mag2 parameter phase a b n lines of VECTOR data datecode cpu dsp fpga boot RMS data followed by SURGE rms1 rms2 dc1 dc2 ac1 ac2 db1 db2 pk1 pk2 cf1 cf2 surgel surge2 level d1 d2 d3 d4 B 3 PSM1735 NumetriQ user manual calibration commands CALAPP CALCOM freq CALFIL index value CALFIL six real data values CALFRQ index freq CALFRQ seven real data values CALI BR index value CALI BR single integer data value CALOUT index value CALPHA index CALRES CALSAV password CALSNO serial number CALSTR string CALSTR string B 4 PSM1735 NumetriQ user manual Appendix C Available character set The following characters can be selected in text entry mode The table is to be read across then down eg starting at space and repeatedly pressing NEXT gives etc i amp 0 1 2 3 4 6 7 8 9 i lt gt O A B C D E F G H J K L M N O P Q R S T U V W xo Y Z De i a b C d e f g h i j k m n O p q r S t u V W x y z PSM1735 NumetriQ user manual Appendix D Configurable parameters All parameters can be accessed using the CONFIG command CONFIG parameter CONFIG parameter data Number Function System parameters 1 operating mode 3 bandwidth auto or wide 4 autozer
22. probe trim probe scaling main inputs probe scaling secondary inputs Connect the instrument output across a convenient resistor anything above 1k using the supplied BNC to crocodile clip output lead Connect the four probes from CH1 CH1 CH2 and CH2 also across the resistor Observe the colour of which probe connects to each of the four input terminals for future use Press OUT and set the generator to 1kHz squarewave with 2V amplitude Press HARM to invoke harmonic analyser mode and select third harmonic Set all probes to x1 To trim the probes connected to the main inputs Select main voltage inputs in the CH1 and CH2 menu the measured third harmonic should read 33 33 0 05 Select x10 on one of the probes and adjust the trimmer in the body of the probe until the third harmonic again reads the same value Switch the probe back to x1 and verify that the third harmonic reads the same Repeat the adjustment if necessary Select x10 on the other probe and adjust in the same way To verify the adjustment at higher frequency select the 25 harmonic for measurement The reading should be 4 00 0 5 in both x1 and x10 settings 9 5 PSM1735 NumetriQ user manual Repeat the procedure for the probes connected to the secondary inputs by selecting secondary voltage inputs in the CH1 and CH2 menu To adjust for the tolerance within the probes typically 1 the main inputs can be scaled and the secondary inputs can be adjus
23. this is impractical for example measuring the turns ratio of a transformer under load In this case turn off the NumetriQ generator OUT menu and the frequency reference for the analysis is measured from channel 1 Provided that the signal is clean enough for an accurate frequency measurement and for DFT analysis the frequency does need to be accurately known then the measurements can be made reliably When using an external frequency reference there can be no sweep function 16 2 PSM1735 NumetriQ user manual 16 1 Turns ratio Turns ratio is computed from the real part of the complex ratio of CH2 divided by CH1 using DFT analysis at the fundamental frequency refer to the chapter on gain phase analysis for the formulae for DFT analysis This technique gives good results even on lossy transformers The polarity of the windings is indicated by a positive turns ratio for in phase windings and negative ratio for inverted windings A nominal number of turns may be entered using the SETUP menu if known and NumetriQ will then also display the computed number of turns As the inputs are independent of the output it is possible to energise a third winding when measuring turns ratio or only two windings may be used To manually connect a transformer for turns ratio connect the NumetriQ output to the winding to be energised and the inputs to the two windings for the ratio Note that when using the transformer analyser fix
24. with your comments E 1 PSM1735 NUMETRIO comments serial main release date number dsp release fpga release boot release press SYS then LEFT your contact details comments detailed description of application or circumstances Please post or fax to Newtons4th Ltd
25. 6 System options Press SYSTEM to access the system options Measurements of phase can be expressed in one of three conventional formats 180 to 180 commonly used in circuit analysis 0 to 360 commonly used in power applications 0 to 360 The measurement is exactly the same it is only the way that it is expressed that changes Blanking can be applied to a number of measurements so that zero is shown when the measurement is below a certain level This blanking can be disabled if desired The graphs on the display and printout may be made up of single points or lines Each key press is normally accompanied by an audible beep as well as the tactile click The beep can be disabled for quiet environments if the feel of the key is sufficient feedback Regular autozero measurements can be suppressed Any measurements that are expressed in units of length eg LVDT can be displayed in metres or inches The shunt value is usually selected automatically when changing function to one that needs a current input such as power meter or LCR meter If the shunt is set to manual rather than default then the shunt value will not be changed When stepping through frequency or amplitude using the cursor keys in real time mode a message is usually 6 1 PSM1735 NumetriQ user manual displayed showing the new value This message can be disabled The 6 main function keys FRA PAV LCR RMS POWE
26. DFT analysis at the fundamental frequency refer to the chapter on gain phase analysis for the formulae for DFT analysis CH2 is forced to be external shunt input enter the value of the external shunt as the source resistance via the SETUP menu To manually connect a transformer for interwinding capacitance measurement connect an appropriate source resistance in series with one winding and connect the NumetriQ output across the transformer from the series resistance to another winding Connect the CHI input across the transformer from one winding to the other to measure the voltage across the windings and CH2 across the series resistance note that the polarity of external shunt input is the opposite of that for voltage When using the transformer analyser fixture the connections for interwinding capacitance are made automatically by relays When measuring small capacitance it may be necessary to zero out stray effects by disconnecting the transformer and pressing ZERO the message ZERO SET will be displayed The transformer analyser fixture TAFO1 has a stray capacitance of around 60pF that can be zeroed out this way To remove the effect of the zero press ZERO followed DELETE within 1 5s and the message ZERO CLEARED will be displayed 16 6 PSM1735 NumetriQ user manual 16 6 Magnetising current The magnetising current is the current drawn by the primary energised under normal operating conditions b
27. M1735 NumetriQ user manual by the scale factor The scale factor can be set automatically by pressing TRIG when in an input channel menu For example with a x10 oscilloscope probe on channel 1 input a x1 probe on channel 2 input and both probes connected to the same voltage press CH1 to invoke the input menu for channel 1 then press TRIG and the scale factor for channel 1 is computed so that channel 1 reads the same as channel 2 Note that when using external divider probes to increase the maximum input voltage it is important to use active probes if accurately measuring dc This because the dc input impedance is different from the ac input impedance When using passive probes the dc would read about 10 high If the channel has been set for use with an external shunt then the value of the shunt can be entered The secondary channel has a control to adjust the gain so that common mode rejection may be maximised when using oscilloscope probes 9 4 PSM1735 NumetriQ user manual 9 1 Trimming x10 oscilloscope probes To minimise the loading effects at high frequencies x10 oscilloscope probes can be used with NumetriQ For optimum performance the probes need to be trimmed to match the input capacitance of the instrument and the probes need to be corrected for gain errors A small plastic screwdriver is provided with each probe for this purpose In all there are three processes that must be carried out to optimise the performance
28. OME and START do not have their normal functions Changing mode also releases hold When HOLD has been activated the DSP continues to sample compute and filter the results but the data is ignored by the CPU When HOLD is released the display is updated with the next available value from the DSP 4 7 PSM1735 NumetriQ user manual 4 7 Parallel port NumetriQ has a logic level parallel port with 8 output lines and 4 input lines which can be used to interface with other parts of a test system or with a PLC The parallel port can be used either as a general purpose I O port under communications control see PPORT and PPORT commands or can be used as a status output 7 6 5 4 3 2 1 0 ALM2 ALM1 ERR DAV bit 0 DAV data available bit 1 ERR data error under or overrange bit 2 ALM1 alarm 1 bit 3 ALM2 alarm 2 The status output is enabled in the ALARM menu By selecting appropriate alarm conditions the status output can be used as a pass fail indicator Parallel port pin connections pin function 2 9 data out DO pin 2 D7 pin 9 10 data in D2 11 data in D3 12 data in DO 13 5V supply 50mA max 15 data in D1 4 8 PSM1735 NumetriQ user manual 4 8 Sweep results store and recall There are 30 non volatile storage locations that can store the results of frequency sweeps Each location can store the sweep results for up to 50 points larger sweeps can be stored in multiple locations
29. PLC interface enable 83 95 96 99 100 101 102 106 107 108 109 116 117 118 119 121 122 123 124 125 126 127 130 131 132 133 PSM1735 NumetriQ user manual Power meter parameters integration type Streaming parameters data streaming data streaming window size Harmonic analyser parameters mode selected harmonic maximum harmonic computation LCR sweep zero parameters sweep compensation compensation start frequency compensation stop frequency compensation steps System parameters dBm level control step message enable display sequence length units Transformer analyser parameters test fixture winding 1 winding 2 source impedance load impedance nominal number of turns TAF control parameters source winding load measure 1 measure 2 D 3 147 148 149 150 151 152 153 154 156 157 158 159 160 161 164 165 167 168 169 170 D 4 PSM1735 NumetriQ user manual LCR meter parameters computation series parallel sweep graph option active head control impedance lin log phase adjust value reference impedance reference type gain phase analyser parameters phase or delay time selection dB offset gain phase margin enable ratio selection System parameters minimum number of cycles delay time IEEE address LAN enable Alarm functions alarm data type high threshold low threshold latching type sounder enable Analogue output parameters a
30. R HARM can be used to load stored configurations as a one touch way of configuring the instrument for specific applications This is particularly useful in a production environment where an operator has a small number of specific tests to perform Levels are usually expressed in volts but can be set and displayed in dBm which is a logarithmic scale referred to 1mW in 6009 often used when testing communications components To save these system settings as default store the setup in program 1 so that they are reloaded on power on Pressing RIGHT from the SYSTEM OPTIONS menu selects the USER DATA screen Pressing LEFT from first SYSTEM OPTIONS menu displays the serial number release versions and calibration date 6 2 PSM1735 NumetriQ user manual 6 1 User data NumetriQ can be personalised by entering up to 3 lines of user data as text see section on text entry User data is displayed every time that the instrument is switched on to identify the instrument The entered text may also be read over the communications to identify the instrument see USER Typical arrangement of the user data might be line 1 company name line 2 department or individual name line 3 unique identifying number eg asset number Any user data may be entered as required as the lines are treated purely as text and are not interpreted by NumetriQ at all For use in a production environment NumetriQ supports two modes of operation su
31. SANAL PSM1735 NumetriQ USER MANUAL Do not be hasty when making measurements The PSM17xx series are precision instruments that provide you with the tools to make a wide variety of measurements accurately reliably and efficiently but good metrology practice must be observed Take time to read this manual and familiarise yourself with the features of the instrument in order to use it most effectively gt gt P pP pP DANGER OF ELECTRIC SHOCK Only qualified personnel should install this equipment after reading and understanding this user manual If in doubt consult your supplier RI SQUE D ELECTROCUTI ON L installation de cet quipement ne doit tre confi e qu un personnel qualifi ayant lu et compris le pr sent manuel d utilisation Dans le doute s adresser au fournisseur GEFAHR VON ELEKTRI SCHEM SCHOCK Nur entsprechend ausgebildetes Personal ist berechtigt diese Ausr stung nach dem Lesen und Verst ndnis dieses Anwendungshandbuches zu installieren Falls Sie Zweifel haben sollten wenden Sie sich bitte an Ihren Lieferanten RISCHIO DI SCARI CHE ELETTRI CHE Solo personale qualificato pu installare questo strumento dopo la lettura e la comprensione di questo manuale Se esistono dubbiconsultate il vostro rivenditore PELI GRO DE DESCARGA EL CTRI CA Solo personal cualificado debe instalar este instrumento despu s de la lectura y comprensi n de este manual de usuario En caso de duda
32. W PC software CommVIEW is a self contained software program for a PC which facilitates communication with NumetriQ over RS232 CommVIEW allows string to be sent and received between a PC and NumetriQ The strings can be viewed in a window and optionally stored in a file Data received from NumetriQ may be displayed in normal scientific notation with an identifying label Strings to be sent to NumetriQ can be stored in a script file and executed automatically The script file is created with any text editor and includes three types of lines interpreted by the first character on each line lines beginning with are sent to NumetriQ lines beginning with are commands for CommVIEW any other line is a comment The commands that are recognised beep sound the beeper on the PC label i string apply a label to data value i pause t wait for time t reply t wait time t for a reply For an example script file look at example scr on the CommVIEW release disc Other functions in CommVIEW Save results results menu set COM port parameters configure menu firmware upgrade instrument menu read store user programs instrument menu A 7 PSM1735 NumetriQ user manual Appendix B Serial command summary command format CLS ESE value ESE ESR IDN OPC RST SRE value SRE STB TRG TST WAI ABORT ACTRIM channel level tol ALARM latch sounder ALARM ALARME value ALARME ALARM 1 type d
33. a number of points over a frequency range This gives results that show the transfer function of the circuit as a graph on the display The DFT analysis yields two components in phase and quadrature or a and b values from which the magnitude and phase can be derived Considering the components at the fundamental frequency The fundamental in phase and quadrature values of a periodic waveform v are given by 21 1 7 v cos o do 0 az 21 bi Ux v sin e de 0 11 1 PSM1735 NumetriQ user manual For a sampled signal the formulae become i n 1 a 1 n DE v i cos 2xci n i 0 i n 1 b 1 n gt v i sin 2xci n i 0 where n is the number of samples for an integral number of complete cycles of the input waveform and c is the number of cycles Having computed the real and quadrature components the magnitude and phase of each channel can be derived mag y ax by 9 tan b a The relative gain and phase of the circuitry under test at that particular frequency is derived from the real and quadrature components by vector division vector gain a jb ch2 a jb chl gain magnitude vector gain phase tan b a vector gain The gain is usually quoted in dB dB 20 log o gain PSM1735 NumetriQ user manual To look at differences in gain from a nominal value an offset gain can be applied either manually or by pressing ZERO o
34. ak if a value of 15V is entered a warning will be given and the amplitude set to the maximum of 10V When the parameter is first selected there is no character cursor visible in this condition a new number may be entered directly and will overwrite the existing number To edit a data value rather than overwrite it press the RIGHT key and a cursor will appear New characters are inserted at the cursor position as the keys are pressed or the character before the cursor position can be deleted with the DELETE key Data values are always shown in engineering notation to at least 5 digits 1 0000 999 99 and a multiplier 3 4 PSM1735 NumetriQ user manual 3 3 Text entry There are occasions where it is useful to enter a text string for example a non volatile program may have some text as a title Text is entered by selecting one of 6 starting characters using the main function keys on the top right hand side of the keyboard FRA etc then stepping forwards or backwards through the alphabet with the UP and DOWN keys The starting letters are A FRA E PAV LCR O RMS U POWER or space HARM Numbers can also be inserted using the number keys The UP and DOWN keys step forward and backward using the ASCII character definitions other printable characters such as or can be obtained by stepping on from the space The available character set is given in the Appendix When entering alphabetic characters t
35. alysis the frequency does need to be accurately known then the measurements can be made reliably When using an external frequency reference there can be no sweep function 14 6 PSM1735 NumetriQ user manual 14 1 LCR meter specification LCR meter frequency 10uHz to 35MHz own generator 20mHz to 35MHz external source measurement type DFT analysis measurements L C R ac Q tans impedance phase admittance series or parallel circuit conditions auto or manual display numeric values table of sweep results graph of any measurement ranges 100pF to 100uF with external luH to 100H shunt 10 to 1MQ ranges 10pF to 1000uF with active head 100nH to 10kH 10mQ to 100MQ basic accuracy 0 1 Tolerance of Shunt sweep step rate 1 20s 1 3s or 2 5s approx Conditions 23 C 5 C ambient temperature instrument allowed to warm up for 230 minutes ac dc coupling autoranging or manual ranging gt 1 3 range using impedance interface adaptor 14 7 PSM1735 NumetriQ user manual 15 Harmonic analyser The NumetriQ harmonic analyser computes multiple DFTs on the input waveforms in real time refer to the chapter on frequency response analysis for the formulae for DFT analysis There are three modes of operation single harmonic difference thd and series thd In single harmonic mode the specified harmonic is displayed both in Volts and as a ratio to the fundamental in either thd mode the computed thd and a
36. ance or leakage inductance are made automatically by relays When measuring small inductance it may be necessary to zero out stray effects by replacing the winding with a good short and pressing ZERO The message ZERO SET will be displayed To remove the effect of the zero press ZERO followed DELETE within 1 5s and the message ZERO CLEARED will be displayed 16 4 PSM1735 NumetriQ user manual 16 3 AC resistance and Q factor AC resistance is measured the same way as inductance with CH1 monitoring the voltage across the winding and CH2 monitoring the current through it via the external shunt source resistance The Q factor measurement is an effective way of detecting a shorted turn either on a transformer or on a choke when using the transformer analyser fixture TAFO2 When using suitable conditions often very different from the normal operating conditions of the device under test the Q factor changes dramatically when a shorted turn is present 16 4 DC resistance DC resistance is measured with the same circuit arrangement as inductance and ac resistance but dc signals are used refer to the chapter on the rms voltmeter for the formulae for dc analysis 16 5 PSM1735 NumetriQ user manual 16 5 Interwinding capacitance The interwinding capacitance of a transformer is computed from the complex ratio of CH1 voltage across the transformer divided by CH2 current through the transformer using
37. and a coarse control to give excellent resolution over the whole range The square wave is generated from the sinewave by a high speed comparator The output has a variable offset added is filtered and is buffered by a high speed high current buffer There is also a TTL Sync output for oscilloscope synchronization etc constantly running at the selected generator frequency The DDS is clocked at 150 MHz The DAC resolution is 12 bit The fine amplitude control is 11 bit 0 05 fsd The coarse amplitude control is 8 bit The maximum output level is 10V peak The maximum output current is 200mA peak The OV of the output is earthed The output impedance is 500 The output frequency range is 10uHz to 35MHz The Sync output is TTL level at generator frequency Sync output attenuate offset square output buffer 1 3 1 2 Voltage inputs Each input consists of a pair of ac or ac dc coupled high impedance buffers one for the main input and one for the secondary The main and secondary inputs can be selected independently to multiplex two signals to the same input or may be used as a single differential input main secondary The secondary input has an adjustable gain accessible from the front panel to trim the CMRR After the selectable heterodyning and filtering there is a series of gain stages leading to an A D converter Selection of the input gain the heterodyning and the sampling of the A D convert
38. ata high low ALARM2 type data high low AMPLIT amplitude BANDWI type BEEP BLANKI on off threshold CONFIG parameter data CONFIG parameter COUPLI channel coupling COUPLI channel DATALO function interval DATALO start records DAV DAVER value DAVER FILTER type dynamics FRA FRA FRA SWEEP FREQUE frequency FSWEEP steps start end reply format single integer data value single integer data value company product serial no version O or 1 single integer data value single integer data value single integer data value single integer data value single integer data value single integer or real data value single integer data value index time data one record per line single integer data value single integer data value freq mag1 mag2 dB phase n lines of GAINPH data B 1 PSM1735 NumetriQ user manual GAINPH GAINPH GAINPH SWEEP HARMON scan para h hmax HARMON or HARMON SWEEP HARMON SERIES HOLD on off INPUT channel type INTYPE channel type INPUT channel KEYBOA value LCR conditions param head LCR or LCR SWEEP or LOWFRE on off MODE type OFFSET offset OUTPUT type sweep PAV parameter scaling PAV PAV SWEEP PHASE PHASE PHASE STREAM window PHCONV convention PHREF channel POWER integration type POWER WATTS POWER RMS POWER INTEGR PPORT value PPORT PROGRAM function number PROGRAM B 2 freq magl1 mag2 dB phase n lines
39. be exactly that programmed The frequency sweep is initiated by the START key and when completed the data can be viewed as a table or graphs or printed out The window over which the measurements are computed is adjusted to give an integral number of cycles of the input waveform In real time mode the results from each window are passed through a digital filter equivalent to a first order RC low pass filter in sweep mode each result comprises a single window without any filtering Very good results can be obtained in a reasonable time using the medium speed setting e g 50 points x 1 3s 17s for the very best results use the slow setting 50 points x 2 5s 125s or 2 minutes 5 seconds The ZOOM function can be used to select up to four parameters from the display when in real time mode It has no function following a sweep 15 2 PSM1735 NumetriQ user manual Although it is most usual to use the NumetriQ generator when making harmonic measurements there may be circumstances where this is impractical for example measuring harmonic currents drawn from the mains In this case turn off the NumetriQ generator OUT menu and the frequency reference for the analysis is measured from channel 1 Provided that the signal is clean enough for an accurate frequency measurement and for DFT analysis the frequency does need to be accurately known then the measurements can be made reliably When using an external frequency referenc
40. d the datalog interval NumetriQ stores the next available measurement after the datalog interval has elapsed the actual elapsed time is attached to each datalog record is displayed with the data on the table or each graph and returned with each record over the communications RS232 LAN or GPIB The data values may be stored to RAM or directly into non volatile memory as each value becomes available The non volatile option is useful for acquiring data over long periods to prevent the loss of data in the event of a power failure Data that has been stored into RAM may be subsequently transferred to non volatile memory using the PROG menu In this mode the data may be viewed in real time as it is being acquired For high speed data acquisition the datalog interval may be set to zero so that each measurement is stored The measurement interval is controlled with the speed option in the ACQU menu Using the window option for speed allows greater control of the measurement interval In this mode the display flashes DATALOG RUNNING and only shows the acquisition time The minimum datalog interval depends on the function but is typically 10ms Note that in all cases the measurement interval is necessarily adjusted to be an integral number of cycles of the measured waveform 7 4 PSM1735 NumetriQ user manual The datalog options are set up with the ACQU menu The datalog is started with the START key and stopped wi
41. d value respectively The repetition rate of the sounder then varies linearly as the value changes between these thresholds 4 5 PSM1735 NumetriQ user manual 4 5 Analogue output The analogue output is a O to 4V dc level that represents the selected measurement To program the analog output first select the functions for the zoom up to four measurements can be selected for the display the alarm is applied to any one of them then press MONITOR to invoke the alarm and analog output menu select which of the zoom functions is to be used set the value for zero volts output set the analog scaling factor The analog output level is computed as output voltage 4 scale measurement zero The output is updated whenever new data is available For maximum update speed select fast analogue output mode in the ACQU menu and enter a window value for 10ms or higher When START is pressed the instrument enters a special mode where all non essential functions are suppressed including the display Press STOP to return to the normal display 4 6 PSM1735 NumetriQ user manual 4 6 Data hold When in real time display mode the data on the display can be held at any time by pressing the REAL TIME key When HOLD is activated a warning message is briefly displayed and the word HOLD appears in the top right hand corner of the display Press the REAL TIME key again or the HOME key or START key to release HOLD in this case H
42. dependent alarms that can be read remotely or can generate an audible sound Each of the alarms can be triggered by comparison to one or two thresholds sound the alarm if the value exceeds a threshold sound the alarm if the value is below a threshold sound the alarm if the value is outside a window sound the alarm if the value is inside a window Additionally one of the alarms can be used to generate a sound which varies linearly between thresholds The value to which each alarm is applied can be any of the measurements selected for zoom The alarm status is also available as a logic output on the parallel port To program an alarm first select the functions for the zoom up to four measurements can be selected for the display the alarm is applied to any of them then press ALARM to invoke the alarm menu select which of the zoom functions is to be used select the type of alarm set the upper limit if appropriate set the lower limit if appropriate select whether the alarm is to be latched select whether the alarm sounder is enabled If the alarm latch is selected then the alarm will continue to sound even if the value returns to within the normal boundaries To clear the alarm press HOME The linear alarm option allows tests to be carried out even if it is not possible to see the display Pressing ZERO in the alarm menu sets the upper and lower threshold to 4 3 and 4 4 PSM1735 NumetriQ user manual 1 3 of the measure
43. e 0 15 reading lt 1kHz 1 5 range 1 5 reading lt 50kHz 2 range 8 reading lt 1MHz accuracy dc 0 2 range 0 3 reading CMRR typical 60dB 10V 50Hz 50dB 10V 1kHz 40dB 10V 1MHz time constant 0 2s 1 5s or 12s Conditions 23 C 5 C ambient temperature instrument allowed to warm up for 230 minutes sinewave power factor gt 0 7 slow speed normal filtering ac dc coupling autoranging or manual ranging gt 1 3 range 0 1 current shunt selected to give 100mV rms 13 5 PSM1735 NumetriQ user manual 14 LCR meter In LCR meter mode channel 1 measures the voltage across the component under test and channel 2 measures the current through it To measure the current channel 2 must be connected across an appropriate external shunt The easiest way to use the LCR meter is with the LCR active head see accessories that fits onto the front of NumetriQ and provides 4 wire Kelvin clip connections to the component under test The active head provides a choice of shunts selectable from the front panel and buffers the signals to minimise the effects of stray capacitance and inductance Measurements can be made without the active head by simply connecting a series shunt set the LCR head option in the SETUP menu to none The shunt chosen must be appropriate for the voltage the current and the frequency of operation There are three manual connection options shunt divider Zx low d
44. e highest range has been determined the range can be set to manual and the measurement made without losing any data due to range changing Pressing the HOME key or sending TRG restarts the autoranging from the selected minimum range When in an input channel menu the ZERO key provides a quick way to lock and unlock the range When no flashing box is visible in the input channel menu and autoranging is selected pressing the ZERO key selects the range that the instrument is currently using and sets the autoranging to manual thus locking the range and preventing further autoranging Pressing the ZERO key again returns to full autoranging from the bottom range For most measurement functions full autoranging is the most suitable option but some applications such as where transient events are occurring are more reliable with manual ranging Manual ranging or up only autoranging is essential for low frequency measurements For measuring signals that are biased on a dc level such as an amplifier operating on a single supply or the output of a dc PSU ac coupling can be used AC DC coupling is the normal option and should be used where possible A scaling factor can be entered for each channel for use with attenuators such as x10 oscilloscope probes A nominal value can be entered or the attenuation factor of the probe can be measured and the precise value entered The measured voltage will be displayed after multiplication 9 3 PS
45. e external shunts From the phase referred fundamental components a jb the following results can be derived magnitude y a b phase tan b a tan o b a in phase ratio a2 al LVDT diff scale a2 al LVDT ratio scale m1 m2 m1 m2 where al and a2 are the in phase components and ml and m2 are the magnitudes of the signals present at chl and ch2 respectively The parameter of interest is selected via the PAV or MODE menu The frequency and phase are always displayed 12 1 PSM1735 NumetriQ user manual A null meter display may be selected via the PAV menu to allow adjustment of a circuit for minimum phase or component The parameter on the display depends on the selected component parameter display null meter in phase in phase quadrature quadrature tan tan tan magnitude magnitude magnitude phase phase rms rms rms2 rms2 1 rms2 rmsl rms2 rmsl in phase ratio in phase ratio in phase ratio LVDT diff LVDT LVDT LVDT ratio LVDT LVDT The null meter may be manually ranged or will automatically range as the signal varies When manually ranging ZOOM and ZOOM adjust the range by a decade There is a phase offset option that applies a vector rotation of a user selectable phase shift to the CH2 input data NumetriQ can operate either in real time mode at a single frequency where the measurements are filtered and updated on the display or it can s
46. e input for the alarm monitoring and analogue output 4 1 PSM1735 NumetriQ user manual 4 2 Program store and recall There are 100 non volatile program locations where the settings for the entire instrument can be saved for recall at a later date Each of the 100 locations has an associated name of up to 20 characters that can be entered by the user to aid identification Program number 1 if not empty is loaded when the instrument is powered on so that NumetriQ can be set to a user defined state whenever it is switched on This is particularly useful to set system options such as phase convention GPIB address etc If no settings have been stored in program 1 then the factory default settings are loaded program number 0 Program numbers 1 6 may be recalled with a single press of the function keys if the direct load option is selected in the system menu see system options The instrument can be restored to the factory default settings at any time by recalling program number 0 The program menu is accessed using the PROG key The program location can be selected either by stepping through the program locations in turn to see the name or by entering the program number directly When storing a configuration in a program there will be a slight pause of about 1 second if the program has previously been written or deleted The process will be very quick if the location has not been used When supervisor mode is disabled se
47. e system options programs can only be recalled not stored nor deleted to avoid accidental modification 4 2 PSM1735 NumetriQ user manual 4 3 Zero compensation There are 3 levels of zero compensation Trim out the dc offset in the input amplifier chain Measure any remaining offset and compensate Measure parasitic external values and compensate The trim of the dc offset in the input amplifier chain is re applied every time that the measurement function is changed or can be manually invoked with the ZERO key or over the RS232 with the REZERO command The measurement of the remaining offset also happens when the offset is trimmed but is also repeated at regular intervals when using a measurement function that requires dc accuracy such as the rms voltmeter This is to compensate for any thermal drift in the amplifier chain This repeated autozero function can be disabled via the SYSTEM OPTIONS menu The compensation for parasitic external values for example to compensate for the capacitance of the test leads when measuring capacitance is invoked manually by the ZERO key Refer to each function section for the function specific operations Any compensation values are stored along with the instrument configuration when a program is stored To restore operation without function specific compensation press ZERO then select the clear option 4 3 PSM1735 NumetriQ user manual 4 4 Alarm function NumetriQ has two in
48. e there can be no sweep function 15 3 PSM1735 NumetriQ user manual 15 1 Harmonic analyser specification Harmonic analyser fundamental frequency harmonic frequency measurement type measurements max harmonic max input input ranges ranging input impedance magnitude accuracy sweep step rate Conditions 10uHz to 500kHz own generator 20mHz to 500kHz external source 10uHz to 1MHz multiple DFT analysis single harmonic differential thd thd by series of harmonics 64 10V peak 10V 3V 1V 300mV 100mV 30mV 10mV 3mV 1mV full auto up only or manual 1M 30pF exc leads 0 1 of fundamental 0 01mV accuracy of fundamental 1 20s 1 3s or 2 5s approx 23 C 5 C ambient temperature instrument allowed to warm up for 230 minutes ac dc coupling autoranging or manual ranging 1 3 range 15 4 PSM1735 NumetriQ user manual 16 Transformer analyser The transformer analyser mode allows a comprehensive set of measurements to be performed on a transformer at a single frequency or automatically swept over a range of frequencies The tests available are turns ratio inductance leakage inductance ac resistance and Q factor dc resistance interwinding capacitance magnetising current insertion loss return loss single harmonic distortion total harmonic distortion longitudinal balance The transformer analyser function is invoked and the test selected by the MODE key The
49. ed out The magnitude of the voltage and current are also computed From the complex impedance the following parameters can be derived ac resistance inductance capacitance impedance phase tans real imaginary Q factor imaginary real Values are displayed for both series and parallel configurations Optionally the values can be expressed as admittance conductance and susceptance instead of impedance resistance and reactance 14 3 PSM1735 NumetriQ user manual If the parameter option in LCR menu is set to auto NumetriQ will display capacitance or inductance according to the phase of the measurement Alternatively the display can be forced to capacitance inductance or impedance Capacitance is displayed with tand inductance is displayed with Q factor and impedance is displayed in its resistive reactive form and as magnitude The phase of the impedance is displayed with all options The operating conditions for the component under test may be selected manually or NumetriQ will automatically try to find appropriate conditions When measuring large electrolytic capacitors it may be necessary to add an appropriate bias voltage to polarise the electrodes In this case it may be necessary to select ac coupling in the CH1 menu in order to reliably measure the small ac voltage present When measuring small inductance or capacitance it may be necessary to zero out the stray effects from the tes
50. ed with the appropriate load resistance and the primary is energised via a source resistance that is equal to the resistance that should be reflected back from the secondary load resistance turns ratio The impedance looking into the primary is measured If z is the complex impedance measured at the primary and R is the source resistance then the return loss is given by return loss z R z R Return loss is usually expressed in dB 20log z R Zz R dB As a figure of merit a higher value of return loss indicates a better transformer The circuit arrangement for return loss is the same as that for inductance measurement except that the secondary is terminated with the appropriate load resistance As the value of the load source resistance R is used in the computation it is important that this value be entered via the MODE menu 16 8 PSM1735 NumetriQ user manual 16 8 Insertion loss Insertion loss is a measure of power loss due to impedance mismatch in signal transformers that are terminated with the design load resistance The secondary winding is terminated with the appropriate load resistance and the primary is energised via a source resistance that is equal to the resistance that should be reflected back from the secondary load resistance turns ratio The voltage energising the series resistance and primary winding is measured and the voltage on the secondary is measured If Rs is the so
51. eed update normal slow time rate time constant constant fast 1 20s 0 25 0 85 medium 1 3s 1 55 6s slow 2 55 12s 48s very slow 10s 48s 192s 7 1 PSM1735 NumetriQ user manual There is also an option to set a specific size of the window to a value other than the preset options In order to synchronise to an integral number of cycles the window size is either reduced by up to 25 or increased as necessary The filter dynamics are usually set to auto reset where the filtering is reset in response to a significant change in data This speeds up the response of the instrument to changing conditions This function can be disabled so that the filtering has a fixed time constant which would have an exponential response to a step change When the generator is not used and so the measurement is synchronised to the input frequency measured on CHI there is a low frequency option that extends the frequency measurement down to 20mHz This low frequency option also applies a digital filter which can be useful when measuring in a low frequency noisy environment The bandwidth of the instrument usually set to auto can be forced to wide or low When not in auto selection heterodyning is disabled and the bandwidth is either 1MHz wide or 50kHz low to minimise noise when making measurements at low frequencies There are three further modes apart from normal Data streaming is a special high speed mode for use wit
52. er are under the control of the DSP There is an autozero switch at the front end for dc accuracy The maximum input is 10V peak The full scale of the lowest range is 1mV peak The input frequency range is dc to 35 MHz The A D converter resolution is 12 bit The A D sample rate is variable to 500k samples s input selection hetero DSP dyning zu amp filtering high Z variable input buffer gain 1 4 PSM1735 NumetriQ user manual 2 Getting started The NumetriQ is supplied ready to use it comes complete with an appropriate power lead and a set of test leads It is supplied calibrated and does not require anything to be done by the user before it can be put into service 2 1 Unpacking Inside the carton there should be the following items one NumetriQ unit one appropriate mains lead four colour coded voltage probes one BNC output lead with clips one null modem cable to connect to a computer this manual Having verified that the entire above list of contents is present it would be wise to verify that your NumetriQ operates correctly and has not been damaged in transit First verify that the voltage rating on the rear of the NumetriQ is appropriate for the supply then connect the mains cord to the inlet on the rear panel of the NumetriQ and the supply outlet Switch on the NumetriQ The display should illuminate with the model name and the firmware version for a few seconds while it performs some in
53. ffset gain measured dB offset dB The filtering is applied to the real and quadrature components individually rather than the derived magnitude and phase values This gives superior results as any noise contribution to the components would have random phase and therefore would be reduced by filtering NumetriQ can operate either in real time mode at a single frequency where the gain and phase are filtered and updated on the display or it can sweep a range of frequencies and present the results as a table or graphs of gain and phase The frequency points to be measured are specified with three parameters number of steps start frequency end frequency NumetriQ computes a multiplying factor that it applies to the start frequency for the specified number of steps Note that due to compound multiplication it is unlikely that the end frequency will be exactly that programmed The frequency sweep is initiated by the START key and when completed the data can be viewed as a table or graphs Following a sweep on a control loop the gain and phase margins can be computed and displayed on the graph The window over which the measurements are computed is adjusted to give an integral number of cycles of the input waveform In real time mode the results from each window are passed through a digital filter equivalent to a first order RC low pass filter in sweep mode each result 11 3 PSM1735 NumetriQ user manual comprises a single windo
54. h communications to a PC see section on RS232 With data streaming the approximate window size is entered and the nearest integral number of cycles is used as the window Fast analogue output mode suppresses the display in order to speed up the processing for analogue output update Single measurement mode makes individual measurements in response to a trigger manually via the 7 2 PSM1735 NumetriQ user manual keypad or TRG over the communications After the measurement the output can be specified to be switched off left on or left on with dc only By setting the measurement window appropriately this mode allows the output to be controlled so that it is only on for the duration of a single measurement Note that the output will always be on for a longer duration than the window period because of settling and ranging time prior to starting the acquisition The duration is typically 25 longer than the requested window for FRA and LCR measurement RMS and POWER have an additional 1 second delay for dc settling 7 3 PSM1735 NumetriQ user manual 7 2 Datalog NumetriQ can store and display measurements recorded at regular intervals over a time period Each data record consists of the elapsed time and up to four data values selected by ZOOM More than 8000 records can be stored if one value is selected more than 3000 if four values are selected The actual interval between data points is governed by the measurement speed an
55. hase can also be independently manually set A vertical marker can be placed on the graph to reference a specific frequency For visual comparison to a reference part with a known response the reference response can be kept on the display drawn with a dotted line while new sweeps are made 1 Set the graph scaling manually 2 Perform a sweep with the reference part 3 Press ZERO to set the reference display 4 Perform a sweep with the part to be compared Each frequency point is an entirely new measurement and autoranging is restarted if enabled For the fastest possible sweeps select manual ranging As each frequency point is a new measurement filtering has no effect on a single sweep but fixed time filtering can be applied 7 6 PSM1735 NumetriQ user manual independently on each frequency point if repeat sweep in selected For maximum sweep speed particularly when using a large number of points there is a fast sweep mode which disables all non essential functions including the display during the sweep In this mode the display is blank except for a flashing message ACQUIRING SWEEP DATA until the full sweep has been completed when normal display functions are restored This mode is automatically selected when a user defined window of less than 100ms has been set Up to 30 sweeps may be stored in non volatile memory using the PROG key Sweeps are stored in blocks of 50 points larger sweeps use contigu
56. he ZOOM and ZOOM keys select upper and lower case respectively for the character preceding the cursor and the next characters to be entered The editing keys RIGHT LEFT DELETE and ENTER operate in the same way as for numeric entry 3 5 PSM1735 NumetriQ user manual 4 Special functions 4 1 Display zoom NumetriQ normally displays many results on the screen in a combination of small font size no zoom and up to 4 values in a larger font size first zoom level There is also an even larger font for up to 4 selected values second zoom level To set the data values for the larger font size first return to no zoom by pressing ZOOM twice if necessary Press ZOOM key to view the presently selected data and press DELETE to clear the selection A flashing box surrounds the first available result The flashing box is moved around the available results using the cursor keys UP DOWN LEFT and RIGHT Pressing the ENTER key selects the result for zoom and the box ceases to flash Further results up to four in total can then be selected using the cursor keys in the same way a Solid box remains around the already selected item and a new flashing box appears Having selected the desired results pressing the ZOOM key invokes the first zoom level pressing it again selects the higher level Pressing ZOOM steps back down one level each time Note that any of the parameters selected for the zoom function can be used as th
57. itial tests It should then default to the RMS voltmeter display Note that the switch on message can be personalised see the User Data section under System Options Note that if there are no leads connected the rms display should read zero If any test leads are connected then 2 1 because of the high impedance of the inputs the rms display may read some random values due to noise pick up If the unit does display any values with no leads connected give the unit thirty minutes to warm up then press ZERO Connect the output lead to the output BNC of the NumetriQ and two input probes to the input BNCs of the two channels Connect the output to both of the inputs by connecting the black clip on the output lead to the OV clip on each of the input probes and the red clip of the output lead to the input probes Note that this is easiest to do by connecting across a resistor any value above 1k Press the OUT key to invoke the output menu then press the UP key to select the output on off control then the RIGHT key to turn on the output Exit the menu by pressing the ENTER button or the HOME button twice The display should now indicate an rms value of about 1 4V on both channels each of which should indicate the 3V range Press the FRA key to select the frequency response gain phase analyser function and check that the gain reads 0 000dB 0 010dB and that the phase reads 0 000 0 010 In the event of any problem with
58. ivider Zx high CH2 ZS GEN CH1 ZX 14 1 PSM1735 NumetriQ user manual For shunt connection shown above the current is measured directly across the shunt using CH2 while the voltage across the Zx is measured by CH1 Notice that the positive inputs to both CH1 and CH2 are connected to the midpoint to minimise common mode loading effects Then ZX ZS x CH1 CH2 For divider Zx low connection shown above the total voltage is measured by CH1 and the voltage arising from the potential divider effect of Zs and Zx is measured by CH2 Notice that all the negative terminals are connected together Then Zx Zs CH1 CH2 1 The connections for divider Zx high are the same as above but with Zx in the high arm of the potential divider and the shunt in the low arm Then Zx Zs x CH1 CH2 1 14 2 PSM1735 NumetriQ user manual NumetriQ measures the real and imaginary components at the fundamental frequency using DFT analysis as described in the section on gain phase analysis The frequency may be taken from its own generator or from the circuitry under test From the fundamental components of voltage a jb and those of the current c jd NumetriQ computes the complex impedance given by Z v i a jb c jd The components of the complex impedance are filtered independently to minimise the effects of noise which would have random phase and would therefore be filter
59. meter The power meter measures the total power and fundamental power of the signal present at the input terminals to the bandwidth of the instrument gt 1MHz Above 1MHz only the fundamentals are measured One of the inputs must be configured as an external shunt input The external shunt may be a simple resistor or dedicated high frequency precision shunts are available as accessories Current transformers and clamps may be used if fitted with a suitable burden resistor For use at mains voltages a mains power adaptor incorporating voltage and current transformers is available The power meter will operate either from its own generator or more normally will use the frequency measured on channel 1 usually voltage The power meter measures the elementary values W V rms A rms V fundamental in phase and quadrature A fundamental in phase and quadrature V dc A dc V harmonic in phase and quadrature A harmonic in phase and quadrature frequency and derives the following values V A fundamental magnitude VA true and fundamental power factor true and fundamental fundamental W harmonic W phase shift 13 1 PSM1735 NumetriQ user manual When the integrator function is activated the following values are available Elapsed time in hours minutes and seconds Watt hours true and fundamental VA hours true and fundamental average power factor true and fundamental Ampere hours true and fundamental The p
60. mpression COMMS communications options RS232 etc ALARM control of audible alarm and analogue output AUX control of auxiliary devices connected to either the front AUX port or rear EXTENSION port OUT signal generator control CH1 channel 1 input control CH2 channel 2 input control SYS general system options such as phase convention keyboard beep etc MODE function control PROG recall store delete of non volatile programs Each menu starts with the currently set parameters visible but no cursor In this condition pressing the menu key again or the HOME key aborts the menu operation and reverts back to normal operation To select any parameter press the UP or DOWN key and a flashing box will move around the menu selecting each parameter In this condition the keys take on their secondary function such as numbers 0 9 multipliers n G etc 3 1 Pressing the HOME key first time reverts to the opening state where the parameters are displayed but the cursor is hidden Pressing the HOME key at this point exits the menu sequence and reverts back to normal operation To abort the menu sequence press the HOME key twice There are three types of data entry selection from a list numeric text 3 2 PSM1735 NumetriQ user manual 3 1 Selection from a list This data type is used where there are only specific options available such as the output may be on or off the graph d
61. nalogue zero analogue scale Alarm functions alarm 2 data alarm 2 type alarm 2 high threshold alarm 2 low threshold 173 174 175 177 178 179 180 181 186 188 190 192 193 194 195 PSM1735 NumetriQ user manual Graph functions graph 2 manual auto graph 2 maximum graph 2 minimum Phase angle voltmeter parameters computation LVDT scaling manual null meter ranging null maximum phase offset Trim parameters ac trim enable ac trim level trim tolerance Other parameters log linear sweep graph scaling manual auto manual graph scaling maximum manual graph scaling minimum D 5 PSM1735 NumetriQ user manual Appendix E Contact details Please direct all queries or comments regarding the NumetriQ instrument or manual to Newtons4th Ltd 1 Bede Island Road Leicester LE2 7EA United Kingdom Tel 0116 230 1066 international 44 116 230 1066 Fax 0116 230 1061 international 44 116 230 1061 E mail address sales newtons4th com office newtons4th com web site www newtons4th com At Newtons4th Ltd we have a policy of continuous product improvement and are always keen to hear comments whether favourable or unfavourable from users of our products An example comment form can be found at the end of this manual if you have any comments or observations on the product please fill a copy of this form with as much detail as possible then fax or post it to us Alternatively send an e mail
62. o manual or auto 5 blanking disable 6 phase convention 7 main output on off 8 line drawing on off 9 keyboard beep on off 11 low frequency mode 12 user window size 13 measurement speed 14 filter type 15 filter dynamics 16 baud rate 17 program step enable 18 sweep steps 19 sweep start frequency 20 sweep stop frequency 21 single sweep continuous sweep 22 auto conditions 23 auto shunt Input parameters 24 enable channel 1 25 enable channel 2 26 input range channel 1 27 input range channel 2 28 input ranging channel 1 29 input ranging channel 2 D 1 30 31 32 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 52 53 54 55 58 59 66 67 D 2 PSM1735 NumetriQ user manual coupling channel 1 coupling channel 2 scale factor channel 1 scale factor channel 2 external shunt channel 1 external shunt channel 2 input connection channel 1 input connection channel 2 General parameters 5 6 digit resolution phase reference output scaling output resolution Display parameters zoom level function zoomed on 1 function zoomed on 2 function zoomed on 3 function zoomed on 4 display type Signal generator parameters generator frequency generator amplitude generator offset generator waveform delta frequency delta amplitude generator amplitude in dBm generator action at end of sweep Datalog parameters datalog memory type datalog interval General parameters program jump enable
63. obe cable screen is driven with the lower source impedance in order to minimise errors at high frequency Note that some modes force the input channels to be voltage or current automatically eg the power meter defaults to channel 1 as voltage and channel 2 as current This automatic selection can be overridden if required 9 1 The input ranges have nominal full scale values set with a ratio of 1 410 from 1mV to 10V When NumetriQ is using selective high frequency measurements heterodyning the ranges extend by approximately 50 This gives the PSM1735 NumetriQ user manual following ranges range reference nominal full scale wideband selective 1 1mV 1mV 1 5mV 2 3mV 3 16mV 5mV 3 10mV 10mV 15mV 4 30mV 31 6mV 50mV 5 100mV 100mV 150mV 6 300mV 316mV 500mV 7 1V 1V 1 5V 8 3V 3 16V 5V 9 10V 10V 10V The maximum input signal that can be accurately measured varies with frequency 9 2 frequency max input level MHz peak V rms V 1 10 7 5 6 4 10 3 2 15 2 1 4 20 1 5 1 25 1 2 0 8 30 1 0 7 35 0 75 0 5 PSM1735 NumetriQ user manual The input ranges may be selected manually or by autoranging default The start range for autoranging may be selected if it is known that the signal will not be below a certain level There is also an option to autorange up only so that a test may be carried out to find the highest range Once th
64. of GAINPH data freq magl mag2 hmagl1 hmag2 h1 h2 freq magl mag2 thd1 thd2 h1 h2 n lines of HARMON data mag1 1 61 mag2 2 62 1 line for each harmonic single integer data value freq magl mag2 impedance phase R L C series R L C parallel tans Q reactance freq magl mag2 impedance phase resistance reactance admittance phase conductance susceptance n lines of data freq QF tand impedance phase L C R freq QF tand admittance phase L C R freq magl mag2 parameter phase a b n lines of VECTOR data freq phase phase phase phase phase phase W W f VA VA f pf pf f Vdc W h freq rms1 rms2 dc1 dc2 fnd1 fnd2 41 42 Wh Wh f VAh VAh f pf pf f Ah Ah f t single integer data value CR terminated text string PSM1735 NumetriQ user manual RANGE ch ranging range RESOLU format REZERO SCALE channel factor SCALE channel SHUNT channel resistance SHUNT channel SINGLE on off SPEED speed window SSWEEP function number START STATUS channel STOP STREAM enable window STREAM disable STREAM SUSPEND on off TFA TFA TFA SWEEP TXA test fixture load source TXA TXA SWEEP TXTEST test windl wind2 USER VECTOR parameter scaling VECTOR VECTOR SWEEP VERSION VRMS VRMS VRMS RMS VRMS SURGE WAVEFO type ZERO ZERO DELETE ZOOM level d1 d2 d3 d4 ZOOM single real data value single real data value range number range text over low
65. onnected across the secondary It is usual to measure harmonic distortion with the secondary loaded Specify the single harmonic or the maximum series harmonic via the SETUP menu NumetriQ analyses for up to 50 harmonics in real time using multiple DFTs refer to the chapter on gain phase analysis for the formulae for DFT analysis Each harmonic is individually phase referenced to the fundamental so that the in phase and quadrature components can be separately filtered As the harmonics are usually very small this technique is important to give adequate noise rejection The series harmonic data is combined to give the thd refer to the chapter on harmonic analysis for the thd formula The single harmonic and the thd are expressed as dB relative to the fundamental 16 11 PSM1735 NumetriQ user manual 16 10 Longitudinal balance Longitudinal balance is a measure of the common mode rejection ratio CMRR of the transformer Longitudinal balance requires external circuitry to give the required accuracy a plug in module is available for the transformer analyser fixture TAFO1 with precision resistors and active buffers adjacent to the transformer pins to minimise stray effects As a figure of merit a higher value of longitudinal balance indicates a better transformer 16 12 PSM1735 NumetriQ user manual Transformer analyser specification Transformer analyser frequency 10uHz to 35MHz own generator 20mHz to 500kHz
66. ous blocks eg steps in blocks per max number sweep sweep of sweeps 2 50 1 30 51 100 2 15 101 150 3 10 151 200 4 7 201 250 5 6 251 500 8 3 501 1000 15 2 1001 2000 30 1 7 7 PSM1735 NumetriQ user manual 7 4 TRIM Trim function The trim function on NumetriQ is a powerful and versatile feature that allows closed loop control of the generator amplitude It allows a specific measurement to be programmed for either CH1 and CH2 and the generator output will be adjusted to maintain the measured voltage or current This allows the excitation level to be controlled over changing conditions such as a frequency sweep At each measurement point the measured level is checked against the specified level and tolerance if an adjustment is needed the data is discarded and a new measurement made at the new output level The user is alerted to the adjustment by an audible beep Particularly important in control loop analysis where it is sometimes referred to as amplitude compression it prevents the control loop being overdriven as the frequency changes It is also useful in a more general case where test levels are specified Note that when dBm mode level control is selected the trim level is entered as dBm but the tolerance remains a linear percentage of the actual voltage not the logarithmic dBm measure 7 8 PSM1735 NumetriQ user manual 8 Output control The output for the signal gene
67. ower dissipated in a load subjected to a periodic voltage v 4 with a current flowing a 6 is given by 21 w 1 2r vid a d dy 0 For a sampled signal the formula becomes i n 1 w 1 n Y vlil ali i 0 where n is the number of samples for an integral number of complete cycles of the input waveform These are elementary definitions that are valid for all waveshapes NumetriQ computes the true watts value from the elementary definition for sampled data Formulae for the components at the fundamental frequency are given in the section on frequency response analysis formulae for the harmonic components are given in the section on harmonic analysis The formulae for the derived results are VA Vims X Arms 13 2 PSM1735 NumetriQ user manual power factor Watts VA fundamental Watts Vreai X Areal Vquad X Aquad harmonic Watts VHrea X AHrea VHguad X AHquad fundamental VA Vrund X Afund fund power factor Wrung VArund In power meter mode the UP and DOWN key do not adjust the amplitude but step the harmonic number The measurements are computed over rectangular windows with no gaps The processing power of the DSP allows the measurements to be made in real time without missing any samples In this way the measured power is a true value even if the signal is fluctuating The only occasion when data is missed is when an autozero measurement is requested this can be disabled in the SYTEM OPTIONS menu
68. pervisor and user When supervisor mode is disabled the stored programs can only be recalled not changed In user mode NumetriQ will also not accept any commands which could change the calibration data After changing the user data or supervisor status execute store to save the data in non volatile memory 6 3 PSM1735 NumetriQ user manual 7 Measurement options 7 1 ACQU Acquisition options In normal acquisition mode the window over which the measurements are computed is adjusted to give an integral number of cycles of the input waveform The results from each window are passed through a digital filter equivalent to a first order RC low pass filter There are four pre set speed options fast medium slow and very slow that adjust the nominal size of the window and therefore the update rate and the time constant of the filter Greater stability is obtained at the slower speed at the expense of a slower update rate Note that at low frequencies the window is extended to cover a complete cycle of the input waveform even if this is a longer period than the nominal update rate There are two time constants for the filter normal or slow or the filter can be deselected The filter applies an auto reset function to give a fast dynamic response to a change of measurement this function can be deselected and the filter forced to operate with a fixed time constant for use with noisy signals The nominal values are sp
69. ponse gain phase analyser frequency 10uHz to 35MHz own generator 20mHz to 35MHz external source max input 10V peak input ranges 10V 3V 1V 300mV 100mV 30mV 10mV 3mV 1mV ranging full auto up only or manual input impedance 1M 30pF exc leads gain accuracy 0 01 dB 0 0001 dB kHz lt 1MHz 0 1 dB 0 04 dB MHz lt 35MHz phase accuracy 0 01 lt 10kHz 0 05 0 0001 kHz lt 35MHz sweep step rate 1 20s 1 3s or 2 5s approx Conditions 232C 52C ambient temperature instrument allowed to warm up for gt 30 Minutes ac dc coupling autoranging or manual ranging gt 1 3 range 11 5 PSM1735 NumetriQ user manual 12 Phase angle voltmeter vector voltmeter A phase angle voltmeter or vector voltmeter or phase sensitive voltmeter measures the signal at one input compared to the phase of the signal at a reference input The results may be expressed as magnitude and phase or as separate in phase and quadrature components NumetriQ measures the in phase and quadrature components at the fundamental frequency using DFT analysis as described in the section on frequency response analysis CH2 the measurement input is phase referred to CH1 the reference input The individual components are filtered separately to minimise the effects of noise which would have random phase and would therefore be filtered out The true rms of the input signals is also computed CH1 and CH2 may be voltage inputs or may us
70. r of menus available to configure the instrument All of these menus are directly accessible with one press of the appropriate menu key The cursor keys allow navigation around the menus and also control the generator when not accessing a menu For example to turn on the output press OUT to bring up the generator control menu press UP to select the output on off option press RIGHT to turn on the output Press ENTER or HOME twice to exit the menu Press FRA to select frequency response analyser mode and the instrument will now display the gain and phase of the transfer function of the circuit under test at the spot frequency specified by the output control menu Press LEFT or RIGHT to adjust the frequency Press UP or DOWN to adjust the amplitude use the OUT menu to change the size of the steps Press START and NumetriQ will start a frequency sweep over the specified range set in the SWEEP menu press TABLE to see the table of results GRAPH to see a graph of the results and REAL TIME to return to the real time data 2 4 PSM1735 NumetriQ user manual 3 Using the menus NumetriQ is a very versatile instrument with many configurable parameters These parameters are accessed from the front panel via a number of menus Each of the main menus may be accessed directly from a specific key ACQU data acquisition parameters such as speed and filtering SWEEP frequency sweep control TRIM generator trim control amplitude co
71. rator is digitally synthesised at an update rate of 150Msamples s With the output filtering this gives a good sinewave waveform even at 35MHz while preserving very accurate frequency control The output amplitude is controlled in 2 stages a fine control with 11 bit resolution and a coarse control with 8 binary weighted steps This gives 5mV resolution at high output levels and very fine resolution at low output levels Peak output level resolution 5V 10V 5mV 2 5V 5V 2 5mV 1 25V 2 5V 1 25mV 0 62V 1 25V 0 62mV 0 31V 0 62V 0 31mV 0 15 0 31V 0 15mV 75mV 150mV 75uV gt 75mV 40uV The maximum output available from the generator is a function of frequency max frequency output level into 500 MHz peak V rms V 5 5 3 5 10 3 2 15 2 1 4 20 1 5 1 25 1 2 0 8 30 1 0 7 35 0 75 0 5 8 1 PSM1735 NumetriQ user manual An offset may be added to any output to bias the signal or to null out any dc present with a resolution of 5mV The LEFT and RIGHT keys adjust the frequency of the generator by a fixed increment stored via the STEP menu the UP and DOWN keys adjust the amplitude except for the harmonic analyser and power analyser where UP and DOWN step the selected harmonic The generator output may be set to be on off or dc only 8 2 PSM1735 NumetriQ user manual 8 1 Generator specifications accuracy frequency 0 05 amplit
72. rawing algorithm may use dots or lines When the flashing cursor is highlighting the parameter the RIGHT key steps forward through the list and the LEFT key steps backwards through the list The number keys 0 9 step directly to that point in the list which provides a quick way to jump through long lists There is no need to press the ENTER key with this data type For example if the speed selection list comprises the options very slow item 0 slow item 1 medium item 2 fast item 3 window item 4 and the presently selected option is medium there are 3 ways to select window press RIGHT twice press LEFT three times press number 4 3 3 3 2 Numeric data entry Parameters such as frequency and offset are entered as real numbers frequency is an example of an unsigned parameter offset is an example of a signed parameter Real numbers are entered using the number keys multiplier keys decimal point key or key if signed value is permitted When the character string has been entered pressing the ENTER key sets the parameter to the new value Until the ENTER key is pressed pressing the HOME key aborts the data entry and restores the original number If a data value is entered that is beyond the valid limits for that parameter then a warning is issued and the parameter set as close to the requested value as possible For example the maximum amplitude of the NumetriQ generator is 10V pe
73. ries impedance of 500 The output adapter fits directly onto the front of the instrument and provides 2 outputs 759 via a BNC connector 6000 via 4mm sockets There are two versions of the adapter that have different spacing between the 4mm sockets 1 12 5mm as commonly used for communications 4 19mm as standard on instruments In both cases the red connector carries the output signal the green or black connector is OV connected to earth via the NumetriQ chassis The impedance conversion is resistive and does not limit the frequencies available from the generator dc coupled When driving into the characteristic impedance 750 or 6000 as appropriate the voltage delivered to the load will be half that delivered into open circuit Matching the source to the load impedance minimises reflections at higher frequencies and improves transient response especially when driving long lengths of cable or transformers Part numbers 500 005 75 6000 adaptor with Y spacing 500 026 75 6000 adaptor with 34 spacing A 3 PSM1735 NumetriQ user manual LCR active head The NumetriQ LCR active head fits onto the front of the instrument making connection to the output and the two inputs to provide four BNC connections for use with Kelvin leads to connect to the component under test A cable from the active head connects to the AUX port on the front of the NumetriQ to allow selection of one of the three internal shunts
74. s is measured from channel 1 Provided that the signal is clean enough for an accurate frequency measurement and for DFT analysis the frequency does need to be accurately known then the measurements can be made reliably When using an external frequency reference there can be no sweep function 12 3 PSM1735 NumetriQ user manual 12 1 Phase angle voltmeter specification Phase angle voltmeter vector voltmeter frequency measurement type measurements max input input ranges ranging input impedance basic accuracy phase accuracy phase resolution tan resolution CMRR typical sweep step rate Conditions 10uHz to 35MHz own generator 20mHz to 1MHz external source DFT analysis and true rms magnitude phase in phase quadrature components tano in phase ratio LVDT diff LVDT ratio rms rms ratio 10V peak 10V 3V 1V 300mV 100mV 30mV 10mV 3mV 1mV full auto up only or manual 1M 30pF exc leads 0 05 range 0 05 reading 0 05mV lt 1kHz basic 0 001 kHz lt 10kHz basic 0 002 kHz lt 1MHz basic 1 6 0 4 MHz lt 35MHz 0 01 lt 10kHz 0 05 0 0001 kHz lt 35MHz 0 001 0 0001 60dB 10V 50Hz 50dB E 10V 1kHz 40dB O 10V 1MHz 1 20s 1 3s or 2 55 approx 23 C 5 C ambient temperature instrument allowed to warm up for 230 minutes ac dc coupling autoranging or manual ranging gt 1 3 range PSM1735 NumetriQ user manual 13 Power
75. specified harmonic are displayed as a ratio to the fundamental In difference thd mode the thd is computed from the rms and fundamental thd 1 h1 V rms2 h 2 In series thd mode the thd is computed from a series of up to 64 harmonics i n thd 1 h V hi where h is the i harmonic i 2 In series mode the magnitude and phase of all the harmonics can be seen as a table or the magnitudes can be displayed as a bargraph which changes in real time with the measurements When viewing the bargraph ZOOM and ZOOM change the vertical axis by a factor of 10 In all cases the harmonics are phase referred to CH1 fundamental so that their in phase and quadrature components may be separately filtered to minimise noise 15 1 PSM1735 NumetriQ user manual The single harmonic and the thd are expressed relative to the fundamental either as a percentage or in dB as selected via the HARM menu NumetriQ can operate either in real time mode at a single frequency where the measurements are filtered and updated on the display or it can sweep a range of frequencies and present the results as a table or graphs The frequency points to be measured are specified with three parameters number of steps start frequency end frequency NumetriQ computes a multiplying factor that it applies to the start frequency for the specified number of steps Note that due to compound multiplication it is unlikely that the end frequency will
76. t connections Press ZERO to access the compensation menu For inductance connect together the test leads to a good short and select short circuit the message SHORT CIRCUIT ZERO SET will be displayed for Capacitance disconnect the test leads and press ZERO the message OPEN CIRCUIT ZERO SET will be displayed To remove the zero press ZERO then press DELETE within 1 5s the message ZERO CLEARED will be displayed For repeated measurements under the same test conditions eg production testing of a batch of capacitors it is possible to compensate for the inherent phase shift of the connection jig Connect a known reference component to the system enter the known phase shift of the component as the phase reference in the ZERO menu 14 4 PSM1735 NumetriQ user manual and select phase adjust NumetriQ then applies a compensating vector rotation to all subsequent measurements NumetriQ can operate either in real time mode at a single frequency where the measurements are filtered and updated on the display or it can sweep a range of frequencies and present the results as a table or graphs Before performing a sweep either series circuit or parallel circuit must be selected The frequency points to be measured are specified with three parameters number of steps start frequency end frequency NumetriQ computes a multiplying factor that it applies to the start frequency for the specified number
77. ted Press OUT and set 1kHz sinewave 2V amplitude and press FRA to invoke frequency response analyser To adjust for tolerance within the probes connected to the main inputs select main voltage inputs in the CH1 and CH2 menu and with both probes set to x1 check that the measured magnitudes of CH1 and CH2 are about the same Set the probe connected to CH1 main input to x10 and set the probe connected to CH2 main input to xl Press CH1 then TRIG the scaling factor for channel 1 will be automatically adjusted to a number about 10 Press HOME to exit the menu and observe that the readings for CH1 and CH2 are again about the same Set the probe connected to CH1 main input to x1 and set the probe connected to CH2 main input to x10 Press CH2 then TRIG the scaling factor for channel 2 will be automatically adjusted to a number about 10 Press HOME to exit the menu and observe that the readings for CH1 and CH2 are again about the same To adjust for tolerance within the probes connected to the secondary inputs select secondary voltage inputs in the CH1 and CH2 menu and with both probes set to x1 check that the measured magnitudes of CH1 and CH2 are about the same and are about the same as when using the probes connected to the main inputs Select differential voltage inputs in the CH1 and CH2 menu and adjust the TRIM potentiometer adjacent to the inverting inputs to obtain the minimum magnitude readings 9 6 PSM1735 NumetriQ user manual
78. th the STOP key unless the store becomes full first The zero reference for the elapsed time is taken as the first data measurement after START The data can be viewed as a table or as individual graphs Pressing GRAPH steps the graph through the stored parameters If more than 250 records have been stored the graph can show the data for the whole period or pressing ZOOM redraws the graph to show 250 records about the cursor The cursor can be moved in single steps LEFT or RIGHT or large steps UP or DOWN Pressing UNZOOM shows the whole data gain Movements of the cursor are synchronised in both the TABLE and GRAPH views 7 5 PSM1735 NumetriQ user manual 7 3 SWEEP Frequency sweep options All ac measurements using the NumetriQ generator can be swept across a frequency range The start frequency stop frequency and number of steps up to 2000 can be specified The measurements are subjected to the same speed constraints set in the ACQU menu but the filtering does not apply on each measurement point If continuous sweep is selected then the filtering is applied to each successive sweep At the end of a sweep the generator may be set to be on off or dc only The settings used are those in the normal generator menu The graph normally sets the y axis automatically to the extremes of the measurements or in FRA mode to 20dB decade of frequency but the axis can be fixed if required The graph of the second parameter usually p
79. this procedure please contact customer services at Newtons4th Ltd or your local authorised representative contact addresses and telephone numbers are given in the appendix at the back of this manual 2 2 PSM1735 NumetriQ user manual 2 2 Keyboard and controls The keyboard is divided into 5 blocks of keys display control 5 keys top left function keys 6 keys top right setup keys 12 keys lower left menu control keys 7 centre keys action keys 4 keys lower right In normal operation the cursor keys give one touch adjustment of various parameters such as generator amplitude and frequency without having to access the menu system The setup keys provide access to the menus and are used for numeric data entry The function keys FRA PAV LCR RMS POWER and HARM are also used for entering the multipliers G M k m u n for date entry and letters for text entry 2 3 2 3 Basic operation Once the unit has powered on and is displaying the default RMS voltmeter screen the required function can be selected by pressing the function key FRA PAV LCR RMS POWER or HARM Pressing the same function key again brings up the menu options specific to that function For example after the unit has powered on in RMS mode press PAV to select phase angle voltmeter mode press PAV again to gain access to the PAV specific menu options Alternatively press MODE to bring up the function specific menus There are a numbe
80. ture the transformer is always energised through the source resistance Pressing ZERO makes the turns ratio read 1 1 and the computed number of turns equal to the value entered via SETUP This allows accurate testing of transformers or chokes against a known good reference Press ZERO followed by DELETE to restore true turns ratio measurement 16 3 PSM1735 NumetriQ user manual 16 2 Inductance amp leakage inductance The inductance of a winding is computed from the complex ratio of CH1 voltage across the winding divided by CH2 current through the winding using DFT analysis at the fundamental frequency refer to the chapter on gain phase analysis for the formulae for DFT analysis CH2 is forced to be external shunt input enter the value of the external shunt as the source resistance via the SETUP menu To manually connect a transformer for inductance measurement connect an appropriate source resistance in series with the winding and connect the NumetriQ output across the series combination of the source resistance and winding Connect the CH1 input across the winding to measure the voltage and CH2 across the series resistance note that the polarity of external shunt input is the opposite of that for voltage Leave all other windings open To manually measure leakage inductance use the same set up as for inductance but short the other windings When using the transformer analyser fixture the connections for induct
81. ude 5 10 lt 35MHz accuracy with amplitude 1 lt 10MHz trim output impedance 500 2 output voltage 10V peak offset 10V peak maximum waveforms sine and square frequency 10uHz to 35MHz output control 5mV to 50uV steps type direct digital synthesis update rate 150MHz DAC resolution 12 bit phase 48 bit accumulator 8 3 PSM1735 NumetriQ user manual 9 Input channels The two input channels each have two separate ground referenced inputs that can be used independently or together as a differential input The two channels are controlled independently but sampled synchronously Each input channel may be selected to use single ended main input single ended secondary input differential main secondary input Each input channel may be selected to be disabled voltage external shunt If the external shunt option is selected the data is scaled by the shunt value entered under the relevant channel menu and the units are displayed in Amps Any resistor can be used as a shunt or precision low inductance current shunts are available as accessories Current transformers can be used if fitted with an appropriate burden resistor Note that the external shunt input polarity is reversed compared to that of the voltage input e the input becomes non inverting and the input becomes inverting This is to be consistent with other instruments having single inputs so that the capacitance to ground of the pr
82. urce resistance the power into the transformer is computed as Win Vin 4 Rs If Rl is the load resistance the power out is computed as Wout Vout RI Insertion loss then is given by Insertion loss Win Wout Vin Vout RI 4 Rs Insertion loss is usually expressed in dB 10 log Vin Vout RI 4 Rs dB As a figure of merit a lower value of insertion loss indicates a better transformer To manually connect a transformer for insertion loss measurement fit the appropriate source resistance in series with the primary winding then connect the NumetriQ 16 9 PSM1735 NumetriQ user manual output and CH1 differential input across the series combination of the source resistance and the primary winding Connect the appropriate load resistance and CH2 differential input across the secondary When using the transformer analyser fixture the connections for insertion loss are made automatically by relays As the values of the load resistance Rl and the source resistance Rs are used in the computation it is important that both values are entered via the MODE menu 16 10 PSM1735 NumetriQ user manual 16 9 Harmonics and distortion Harmonic distortion introduced by a signal transformer may be measured either at a single spot harmonic or as the thd computed from a series of harmonics The primary of the transformer is energised either by the output of NumetriQ or by external means and CH2 is c
83. ut without any secondary load It is typically measured on power transformers rather than signal transformers so although the transformer analyser fixture TAFO1 will select appropriate relays to make the measurement it is more common that a manual connection or a custom fixture would be used The magnetising current is measured as the true rms value refer to the chapter on the rms voltmeter for the formulae for rms analysis so it will include all distortion components To manually connect a transformer for magnetising current measurement connect an appropriate shunt in series with the primary When selecting the shunt bear in mind the current that it must pass the resulting voltage drop across it and the power that will be dissipated in it Connect CH1 directly across the primary winding using a pair of appropriate probes and CH2 across the series resistance with a second pair of probes note that the polarity of external shunt input is the opposite of that for voltage Ensure that all probes and the series resistance are appropriate for the voltage the current and the frequency of operation Energise the primary so that the voltage seen at the primary after the series resistance is the normal operating voltage 16 7 PSM1735 NumetriQ user manual 16 7 Return loss Return loss is a measure of impedance mismatch in signal transformers that are terminated with the design load resistance The secondary winding is terminat
84. w without any filtering unless repeat sweep is selected The top of the vertical axis for the graph is normally set to be the highest measured value during the sweep The bottom of the vertical axis is normally either set to the lowest measured value or the result of the highest value less 20dB decade of frequency The vertical axis can be fixed to a manual scale using the menus The ZOOM function can be used to select up to four parameters from the display when in real time mode It has no function following a sweep Following a sweep the GRAPH key selects between graph of gain v frequency graph of phase v frequency graph of gain and phase v frequency Pressing HOME or TRIG restarts the real time measurement at the selected frequency Although it is most usual to use the NumetriQ generator when performing gain phase analysis there may be circumstances where this is impractical for example measuring across a transformer under load In this case turn off the NumetriQ generator OUT menu and the frequency reference for the analysis is measured from channel 1 Provided that the signal is clean enough for an accurate frequency measurement and for DFT analysis the frequency does need to be accurately known then the gain and phase can be measured reliably When using an external frequency reference there can be no sweep function 11 4 PSM1735 NumetriQ user manual 11 1 Frequency response analyser specification Frequency res
85. weep a range of frequencies and present the results as a table or graphs Before performing a sweep the desired parameter must be selected The frequency points to be measured are specified with three parameters number of steps start frequency end frequency 12 2 PSM1735 NumetriQ user manual NumetriQ computes a multiplying factor that it applies to the start frequency for the specified number of steps Note that due to compound multiplication it is unlikely that the end frequency will be exactly that programmed The frequency sweep is initiated by the START key and when completed the data can be viewed as a table or graphs or printed out The window over which the measurements are computed is adjusted to give an integral number of cycles of the input waveform In real time mode the results from each window are passed through a digital filter equivalent to a first order RC low pass filter in sweep mode each result comprises a single window without any filtering The ZOOM function can be used to select up to four parameters from the display when in real time mode It has no function following a sweep Although it is most usual to use the NumetriQ generator when making Phase Angle Voltmeter measurements there may be circumstances where this is impractical for example measuring LVDT displacement under actual circuit conditions In this case turn off the NumetriQ generator OUT menu and the frequency reference for the analysi

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