BDM40-UA Bench Digital Multimeter Product Manual
Contents
1. BDM40 UA Bench Digital Multimeter AMPROBE BDM40 UA Bench Digital Multimeter User Manual PN 1675449 March 2007 2007 Amprobe Test Tools All rights reserved Printed in Taiwan Limited Warranty and Limitation of Liability Your Amprobe product will be free from defects in material and workmanship for 1 year from the date of purchase This warranty does not cover fuses disposable batteries or damage from accident neglect misuse alteration contamination or abnormal conditions of operation or handling Resellers are not authorized to extend any other warranty on Amprobe s behalf To obtain service during the warranty period return the product with proof of purchase to an authorized Amprobe Test Tools Service Center or to an Amprobe dealer or distributor See Repair Section for details THIS WARRANTY IS YOUR ONLY REMEDY ALL OTHER WARRANTIES WHETHER EXPRESS IMPLIED OR STAUTORY INCLUDING IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY ARE HEREBY DISCLAIMED MANUFACTURER SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES ARISING FROM ANY CAUSE OR THEORY Since some states or countries do not allow the exclusion or limitation of an implied warranty or of incidental or consequential damages this limitation of liability may not apply to you CONTENTS CERTIFICATIONS AND PRECAUTIONS see enne 3 SYMBOLS USED IN THIS2. Blue Neutral Brown Live Phase As the colours of the wires in main leads may not correspond with the colours marking identified in your plug appliance proceed as follows The wire which is coloured Green amp Yellow must be connected to the Earth terminal marked with the letter E or by the earth symbol or coloured Green or Green amp Yellow The wire which is coloured Blue must be connected to the terminal which is marked with the letter N or coloured Blue or Black The wire which is coloured Brown must be connected to the terminal marked with the letter Lor P or coloured Brown or Red If in doubt consult the instructions provided with the equipment or contact the supplier This cable appliance should be protected by a suitably rated and approved HBC mains fuse refer to the rating information on the equipment and or user instructions for details As a guide cable of 0 75 mm should be protected by a 3A or 5A fuse Larger conductors would normally require 13A types depending on the connection method used Any moulded mains connector that requires removal replacement must be destroyed by removal of any fuse amp fuse carrier and disposed of immediately as a plug with bared wires is hazardous if engaged in live socket Any re wiring must be carried out in accordance with the information detailed on this instruction INTRODUCTION This instrument is a line powered bench type digital multimeter with a 4 1 2 digit LED display The DMM
3. 200mV 2V 1000Vrms for no longer than 15 sec 2A DC or mA 20A and Fuse protected F 2A 250V A ALL RANGES 204 AC COMMON Not fused V Q and kQ ALL RANGES 250VDC or VAC rms COMMON MEASUREMENT TECHNIQUES The information provided here describes techniques in measurement and interpretation of measurements that may extend the usefulness of your DMM These techniques common throughout the electronics industry have been tailored specifically for this instrument AC Measurement Techniques When making precise measurements of AC signals there are special parameters that must be considered such as the type of AC converter the meter uses average rms etc crest factor bandwidth noise etc True RMS In order to compare dissimilar waveforms calculate Ohm s law statements or power relationships you must know the effective value of a signal If it is a DC signal the effective value equals the DC level If the signal is AC however we have to use the root mean square or rms value The rms value of an AC current or AC voltage is defined as being numerically equal to the DC current or voltage that produces the same heating effect in a given resistance that the ac current or voltage produces In the past average responding converters were the type of converter most widely used Theoretically the rms value of a pure sine wave is 1 V2 of the peak value and the average value is 2 pi of the peak value Since the meters conv
4. following procedure to gain access to the calibration adjustments of this DMM 1 on wm Set the POWER switch to the OFF position and remove the power cord plug from the receptacle in the rear of the instrument Remove the Phillips screw from the Bottom of your DMM Grasp the front panel and slide the instrument out of the case Turn the instrument upside down as viewed from the front panel All adjustments necessary to complete the calibration procedure are now accessible For reassembly reverse the procedure be careful to align the grooves in the sides of the front panel with the guides located inside the case and to bend the flexible interconnect inwards and out of the way Main PCB Access Use the following procedure to gain access to all the components and test points ON THE MAIN PCB ASSEMBLY FOR TROUBLESHOOTING AND REPAIRING 17 1 Complete the calibration access procedure 2 Remove the front panel using the following procedure a The V Q input line and the COMMON input line are attached to the front panel by a snap connector Unplug these lines b Slide the fuse spring forward to the edge of the slide panel c Pull the wire up through the slot in the fuse holder barrel d Pullthe spring and the fuse contact up through the hole in the fuse holder barrel e Reinstall the fuse and fuse holder f Turn the instrument component side down g Carefully pull the front panel free of the switches 3 Toinstall
5. one black two spare fuses 2A two spare fuses 0 08A 230V and 0 125A 117V and 2 power cords 1 115V and 1 230V Check the shipment for damage A CAUTION This meter has dual operating voltages It can be operated from 117VAC or 230VAC source The unit is shipped in the 230VAC configuration with an 0 08A 250 V fuse installed If you plan to use the BDM40 UA on a 117 V source unplug the power cord switch to the 0 125A 250V fuse supplied with instrument and set the rear panel Switch to 117V If the meter maybe damaged if is not setup properly for the source voltage being used The label on the top side of your instrument is marked with the line voltage and frequency required for proper operation Refer to Maintenance section if a change in the input power configuration is desired GETTING ACQUAINTED Your meter is light weight with a low profile and requires little space on the work bench The black case is made of rugged high impact plastic The handle can be rotated to eight positions The right side of your DMM contains two rows of switches and LED display The power cord receptacle is located on the rear panel of your DMM The meter inputs are the 4 inputs on the front panel and are marked for the functions USING YOUR METER The following paragraphs describe each of the controls on your DMM and how these controls can be used for each instrument function Exercises are included to help you familiarize yourself w
6. test leads cracked case display not reading etc do not use Never ground yourself when taking measurements Do not touch exposed metal pipes outlets fixtures etc which might be at ground potential Keep your body isolated from ground and never touch exposed wiring connections test probe tips or any live circuit conductors Do not operate instrument in an explosive atmosphere flammable gases fumes vapor dust Do not use this or any piece of test equipment without proper training SYMBOLS USED IN THIS MANUAL N Refer to the manual gt Alternating Current Dangerous voltage Direct Current Complies with EU E Double Insulation directives 4 Earth Ground Diode This meter is shipped with two power cords The 117 230 volts power switch on the rear panel has been set to 230 volts and the 0 08A fuse installed Please verify the switch and fuse for your location before installing the power cord To change to 117 V operation install proper fuse at back panel see manual and set switch to 117V This instrument is shipped configured for 230 volt operation Operation at 117 VAC requires that the fuse be changed and the proper power cord used FOR UNITED KINGDOM ONLY NOTE This lead appliance must only be wired by competent persons WARNING THIS APPLIANCE MUST BE EARTHED IMPORTANT The wires in this lead are coloured in accordance with the following code Green Yellow Earth
7. the Main PCB reverse this procedure being careful to install the PCBs and the shields in their respective guides Display Access Use the following procedure to remove or replace the LED 1 Carefully lay the display PCB to one side Both the Main and Display PCBs should now be flat on your workbench component side up Tilt the Display PCB towards the Main PCB and remove the shield plate connecting the Display PCB SELLOS PS For reassembly reverse this procedure Performance Tests The performance tests are used to compare the performance of this instrument to the specifications listed in Section 1 of this manual If the instrument fails any portion of the performance tests calibration and or repair is indicated Throughout the tests your DMM will be referred to as the UUT Unit Under Test NOTE Allow the UUT to warmup a minimum of 5 minutes and conduct the tests at an ambient temperature of 23 5 c 73 9 f Display Test Complete the following procedure to verify proper operation of the display annunciators and each segment of each digit in the display 1 Select kO 2000 range with an open circuit input 2 Verify that for over range indication the LED will flash in all digit locations 3 Shortthe input select each range listed in Table 4 and verify that the decimal point is positioned as indicated 4 Select DC V 200V range 5 Connect the DMM Calibrator to the UUT HI to the V O terminal and LO to the CO
8. to 2 0 Figure 2 Crest Factors Your instrument has a crest factor range of 1 0 to 3 0 at full scale Going down from full scale the crest factor capability increases from 3 0 to Full Scale x 3 i e 6 at half scale RMS Value If an input signal has a crest factor of 3 0 or less voltage measurements will not be in error due to dynamic range limitations at full scale If the crest factor of a waveform is not known and you wish to know if it falls within the crest factor of your meter measure the signal with both your meter and an ac coupled oscilloscope If the rms reading on your meter is 1 3 of the peak voltage on the waveform or less then the crest is 3 0 For readings at less than full scale use the preceding formula to determine the maximum crest factor At half scale the maximum crest factor is 2x 3 1 The waveforms in Figure 2 show signals with increasing values of crest factor As you can see from the series of waveforms a signal with a crest factor above 3 0 is unusual For an ac coupled pulse train Crest Factor J 1 D 1 Where D duty cycle or the ratio of pulse width to cycle length Reversing this formula we find that your meter can accurately measure pulse trains at full scale with a duty cycle above 1096 without being limited by crest factor Crest Factor 3 0 J 1 D 1 9 0 1 D 1 10 0 1 0 Bandwidth Bandwidth defines the range of frequencies where the response of the voltmeter s amplifiers is no more than 3
9. voltage to turn on silicon junctions to check for proper forward to back resistance The 2kQ range is preferred and is marked with a large diode symbol on the front panel of the instrument Maximum Input Signal Limits FUNCTION SELECTED RANGE SELECTED INPUTTERMINALS MAXIMUM INPUT OVERLOAD DC ALL RANGES 1200VDC or Peak AC V Qand 20V 200V 1000 1000VDC or Peak AC AC COMMON 200mV 2V 1000Vrms for no longer than 15 sec 2A DC or mA 20A and Fuse protected F 2A 250V A ALL RANGES 20a COMMON Not fused V Qand kQ ALL RANGES 250VDC or VAC rms COMMON OPTIONAL ACCESSORIES DL243D Basic Test Lead Set DL248D Deluxe Test Lead Set TL245A Standard Replacement Test Leads TL36A Test leads with alligator clips TC 253B Temperature Converter 27
10. volts output to the COM terminal For each step in Table 8 select the listed range program the calibrator for the corresponding UUT input and make the specified adjustment or check Table 8 DC Calibration Step Range Input Adjust Display Limits 1 200mV Short VR303 Less than 00 04 2 2V 1 9000V VR302 1 9000V exactly 3 200mV 190 00mV VR304 190 00mV exactly 4 200V 190 00V VR202 190 00V exactly 5 1000V 1000 0V VR203 1 000 0V exactly 21 Ohms Calibration On the UUT select Q 2000 range and connect the V O terminal to the calibrator ohms output and COM to the calibrator LO ohms output For each step in Table 9 select the listed range program the calibrator for the corresponding UUT input and make the specified adjustment or check Table 9 Ohms Calibration Step Range Input Adjust Display Limits 1 20 10 MQ VR402 9 995 to 10 005 2 20 kQ 10 KQ VR401 9 998 to 10 002 DC Current Calibration On the UUT select DC 20 A range and connect the 20A terminal to the calibrator amps output and COM to the calibrator LO amps output For each step in Table 10 select the listed range program the calibrator for the corresponding UUT input and make the specified adjustment or check Table 10 DC Current Calibration Step Range Input Adjust Display Limits 1 20A 1 9A VR206 1 898 to 1 902 2 2 A 2000mA 1 9A VR205 1899 8 t
11. 100 65 13 2V 1 9VAC rms 100Hz 1 8890 to 1 9110 19 14 15 16 17 18 19 20 21 10kHz 1 8890 to 1 9110 50kHz 1 8020 to 1 9980 100Hz 18 890 to 19 110 20V 19VAC rms 10kHz 18 890 to 19 110 50kHz 18 020 to 19 980 190VAC rms 100Hz 188 90 to 191 10 200V 100VAC rms 10kHz 99 35 to 100 65 100Hz 993 5 to 1006 5 100V 1000VAC rms 1kHz 993 5 to 1006 5 Current Test Use the following procedure to verify proper operation of both the AC and DC mA measurement functions 1 2 Select DC mA 200A range Connect the calibrator HI amps output to the V Q terminal and the calibrator LO amps output to the COM terminal For each step in Table 6 select the listed range program the calibrator for the corresponding UUT input and verify that the UUT display value lies within the indicated limits Set the FUNCTION switch to the AC mA position and select the 20 mA range Program the calibrator for a UUT input of 19 000 mA rms at a frequency of 100 Hz Verify that the UUT display value lies between 18 890 and 19 110 Table 6 Direct Current Test STEP ME INPUT DISPLAY READING 1 200uA 190A 189 61 to 190 39 2 2mA 1 9mA 1 8961 to 1 9039 3 20mA 19mA 18 961 to 19 039 4 200mA 190mA 189 61 to 190 39 5 2000mA 1900mA 1894 1 to 1905 9 6 20A 19A 18 941 to 19 059 Resistance Test Use the following procedure to verify the accuracy of the measur
12. ATOR INJURY MAY RESULT IF THE FUSE BLOWS WHILE CURRENT IS BEING MEASURED IN A CIRCUIT WHICH EXHIBITS AN OPEN CIRCUIT VOLTAGE GREATER THAN 600 VOLTS Burden voltage error When a meter is placed in series with a circuit to measure current you may have to consider an error caused by the voltage drop across the meter in this case across the protective fuses and current shunts This voltage drop is called burden voltage The maximum full scale burden voltages for your instrument are 0 3V for the four lowest ranges and 0 9V for the 2000mA 20A ranges These voltage drops can affect the accuracy of a current measurement if the current source is unregulated and the resistance of the shunt and fuse represents a significant part 1 1000 or more of the source resistance If burden voltage does present a problem the percentage error can be calculated using the formula below This error can be minimized by selecting the highest current range that provides the necessary resolution 14 Calculating Burden Voltage Error m Es 4 AMMETER SHUNT E Source voltage R Load resistance Source resistance I Measured current display reading in amps E Burden voltage calculated i e Readin Display reading expressed as a of full scale 100 gc E FullScale times full scale burden voltage for selected range See table RANGE F S BURDEN VOLTAGE 200pA to 200mA 0 3V max 2000mA 1V max 20A 2V max Maximum current err
13. MANUAL ssseeeem eene 3 FOR UNITED KINGDOM ONLY sse enne 4 INTROBUGTION as t te E dete et ett nad 4 UNPACKING YOUR INSTRUMENT esee enne 5 GETTING AGQUAINTED itd rm rre f nates 5 USING YOUR METER B ttn bett tn ted ptc d de o RAT ad 5 OPERATING GUIDELINES 2 riri e tite i Rer he e dea ed 7 MEASUREMENT TECHNIQUES essere 8 VOLTAGE MEASUREMENTS sse 10 CURRENT MEASUREMENT S sse nennen 14 RESISTANCE MEASUREMENTS nee ener rennen 15 DIODE MEASUREMENT ith ede e e a Ra EP 16 MAINTENANCE AND REPAIR sse meer 22 SPEBGIFICATIONS 1 1 e pier i teinte ede eee de aca p eee d ere aet depen 24 OPTIONAL ACCESSORIES sse neret trn 27 CERTIFICATIONS AND PRECAUTIONS This instrument is EN61010 1 certified for Installation Category 1200V Pollution Degree Il Class 2 It may only be used to make measurements on energy limited circuits within equipment All inputs are protected against continuous overload conditions up to the limits of each function s stated input protection see specifications Never exceed these limits or the ratings marked on the instrument itself Always inspect your Multimeter test leads and accessories for signs of damage or abnormality before every use If an abnormal condition exists broken or damaged
14. MMON terminal 6 Apply 188 88VDC and adjust the calibrator until the UUT displays 188 88 exactly 18 Table 4 Display Test SELECT RANGE DISPLAY 2000 00 00 0000 20kQ 0 000 200kQ 00 00 2000kQ 000 0 20MQ 0 000 The least significant digit s may change by several digits from zero depending on your test lead resistance Linear Voltage Test Use the following procedure to verify the proper operation of both the AC and DC V functions 1 Select DC V 200mV range 2 Connect the calibrator HI volts output to the V O terminal and the calibrator LO volts output to the COM terminal 3 Foreach step of Table 5 set the ACV DCV switch to the indicated position select the listed range program the calibrator for the corresponding input to the UUT and verify that the UUT display value lies within the indicated limits Table 5 Linear Voltage Test UUT SWITCH POSITIONS UUT INPUT STEP DISPLAY READING FUNCTION RANGE LEVEL FREQUENCY 1 190mVDC 189 90 to 190 10 200mV 2 190mVDC 189 90 to 190 10 3 5 1 9VDC 18990 to 1 9010 4 1 9VDC 1 8990 to 1 9010 DCV 5 20V 19VDC 18 990 to 19 010 6 200V 190V DC 189 90 to 190 10 7 1200V 1000VDC 999 3 to 1000 7 8 2V Short 0020 ACV 100 Hz 188 90 to 191 10 10 190mVAC rms 10kHz 188 90 to 191 10 200mV 11 50kHz 180 20 to 199 80 12 100mVAC rms 1kHz 99 35 to
15. T DC LEVEL ov Figure 5 RMS Values Insignificance of inherent meter offset If you short the input of your meter while the AC voltage function is selected you should have a reading of less than 10 digits on the display This small offset is caused by the action of amplifier noise and offset of the true rms 13 converter This offset will not significantly affect any readings until you try to measure signals almost at the lower limit of the meter For example Given An offset of 40 digits Given An offset of 20 digits 0 40mV in 200 mV range 0 20mV in 200 mV range Input signal 10mV in 200 mV range Input signal 10mV in 200 mV range Total rms 102 0 42 Total rms v1 02 0 22 4100 0 16 4100 0 04 4100 16 4100 04 10 01 mV 10 00 mV The error will be about 0 01mV the error is not significant CURRENT MEASUREMENTS All of the controls and terminals used to make current measurements are located on the front panel The AC mA and DC mA function switches determine the measurement function The colored area around the 20A switch extends up and to the right to enclose the six range values for the 20A measurement function Push the range switch immediately above the value to be measured As the colored areas around the terminals indicate the red test lead should be plugged into the 2A or 20A terminal and the black test lead should be plugged into the COMMON terminal AA WARNING INSTRUMENT DAMAGE AND OPER
16. ance source impedance is small compared to the input impedance of the meter the error is not significant For example when measuring voltage with your meter as long as the source impedance is 1 or less the error will be lt 01 96 If circuit loading does present a problem the percentage of error can be calculated using the appropriate formula in Figure 4 1 DC Voltage Measurements Loading Error in 100 x Rs Rs Rin Where Source resistance in ohms of the circuit being measured Rin Meter input resistance 1 x 10 ohms 2 AC Voltage Measurements First determine input impedance as follows 107 1 2 Where Zin effective input impedance Zin Rin 10 ohms 100 x 10 Farads F Frequency in Hz Then determine source loading error as follows Zs Zs Zin Loading Error in 100 x Where Zs Source impedance Zin input impedance Vector algebra required Figure 4 Circuit Loading Error Combined AC and DC signal measurements The waveform shown in Figure 5 is a simple example of an AC signal riding on a DC level To measure waveforms such as these first measure the rms value of the AC component using the AC function of your meter Measure the DC component using the DC function of your instrument The relationship between the total rms value of the waveform and the AC component and the DC component is RMS Total Jac component rms DC component AC COMPONEN
17. ature that allows accurate measurement of common waveforms like distorted or mixed frequency sine waves square waves sawtooth waves noise pulse trains with a duty cycle of at least 1096 etc In the past the methods used for AC measurement have introduced large errors in readings Unfortunately we ve all grown used to these erroneous voltage readings and depend upon them to indicate whether or not a piece of equipment is working correctly The data contained in Table 2 should help you convert between measurement methods 11 AC COUPLED INPUT PK WAVEFORM PK PEAK VOLTAGES METERED VOLTAGE AC COMPONENT ONLY DC AC COMPONENT TRUE RMS TRUE RMS ONEX dc DC AND AC TOTAL RMS RMS CAL SINE PK PK PK RECTIFIED SINE FULL WAVE 2723 0 SQUARE WAVE Ai EE A aa 1 414 1 414 PK PK 0 RECTIFIED SINE HALF WAVE Beane 2 000 2 000 SQUARE WAVE RECTIFIED TRIANGLE SAWTOOTH DISPLAY RMS FOR DINE WAVES Your Digital Multimeter ERSEN 1 414 1 414 RECTANGULAR PULSE Pr ab x PK PK o IYI D X Y K o o RMS CAL IS DISPLAYED VALUE FOR AVERAGE RESPONDING METERS THAT ARE CALIBRATED TO Tahle 2 Voltage Conversion 12 Circuit loading error Connecting most voltmeters to a circuit may change the operating voltage of the circuit if it loads the circuit down As long as the circuit resist
18. can measure AC DC volts AC DC current and resistance Among other features e True RMS Measurements of AC or AC DC Signals True RMS measurement is the only accurate way to directly measure AC or AC DC signals that are not noise free pure sine waves This instrument measures AC voltage frequencies up to 50 kHz Five measurement functions e AC and DC VOLTS Standard linear voltage measurements from 10 uV to 1200 VDC and 10 mV to 1000 VAC or AC DC true rms e _ ACand DC Current Standard current measurements from 10 nA to 20 ADC and 10 pA to 20 AAC or AC DC true rms e Resistance Standard resistance measurements from 10 mQ to 20 MQ Each measurement range has Autopolarity operation Overrange indication Effective protection from overloads and transients Dual slope integration measurement technique to insure fast accurate noise free measurements Diode test Ranges of the resistance function that will turn on PN junctions allowing testing of diodes and transistors These ranges are marked with a diode symbol on the front panel of your DMM The preferred 2kO range is marked with the largest diode symbol Improved test leads Finger guards on the probes and shrouded contacts on the input terminals decrease the possibility of accidental contact with circuit voltage Long term calibration accuracy 1 year UNPACKING YOUR INSTRUMENT The shipping box should contain this manual your multimeter test leads one red and
19. dB down half power levels Your instrument has a bandwidth of greater than 200kHz Slew rate Slew rate is also called the rate limit or the voltage velocity limit It defines the maximum rate of change of the output of the amplifiers for a large input signal Slew rate limitations are not a factor in measuring voltages within specified frequencies and amplitude limits of this DMM Rise and fall time effect on accuracy The rise and fall time of a waveform are the length of time it takes a waveform to change between the points that are 10 and 90 of the peak value When discussing these periods we ll only mention rise time Errors due to rise to fall time can be caused either by bandwidth or slew rate limitations Slew rate should not affect your measurement with this DMM Ideal aff fs EM uds DC Level DC Level 50usec 4 le 1 75usec 77 j Distortion A Lx Al MM DC Level DC Level M cp sl za usec BE Aet DO Zk 1 75 T lt 100 Components Example Figure 3 Waveform Distortion An approximate way of converting bandwidth to rise time limit is to divide 0 35 by the 3 dB down frequency For your instrument this will be 0 35 200kHz 1 75 usec The following example will help you calculate errors due to this limitation when measuring rectangular pulses These calculations will be rough because ideal waveforms are used in the analysis Ideally t
20. ement function 1 2 Select 2000 range Connect the calibrator HI ohms output to the V O terminal and the calibrator LO ohms output to the COM terminal 20 3 Foreach step in Table 7 select the listed range program the calibrator for the corresponding input to the UUT and verify that the UUT display is within the indicated limits Table 7 Resistance Test STEP d INPUT DISPLAY READING 1 2000 Short 00 00 to 00 07 2 2000 1000 99 86 to 100 14 3 2kO 1ko 9988 to 1 0012 4 20kQ 10kQ 9 988 to 10 012 5 200kQ 100kQ 99 88 to 10 012 6 2000kQ 1000kQ 997 3 to 1002 7 7 20MQ 10MQ 9 973 to 10 027 Calibration Adjustments The calibration adjustment procedure should be used any time your instrument has been repaired or fails to pass the Performance Test Adjust R306A R336A if U301 U308 are replaced or if VR302 VR304 do not have enough adjustment range Replace U501 if VR502 does not have enough adjustment range The RMS Converter Offset Adjustment should not normally need to be done Adjust only if VR501 AC does not have enough adjustment range or if the display reads 0010 or greater with AC V 2V range selected and the input shorted NOTE Allow the UUT to warm up a minimum of 5 minutes and conduct the calibration at an ambient temperature of 23 5 C 73 9 F DC Voltage Calibration On the UUT select DC V 2V range and connect the calibrator HI volts output to the V Q terminal and the calibrator LO
21. erted to the average value the rms value was 1 2 2 pi pi 2 V2 1 11 of the average value when measuring a sine wave Most meters used an average responding converter and multiplied by 1 11 to present true rms measurements of sine waves As the signal being measured deviated from a pure sine wave the errors in measurement rose sharply Signals such as square waves mixed frequencies white noise modulated signals etc could not be accurately measured Rough correction factors could be calculated for ideal waveforms if the signal being measured was distortion free noise free and a standard waveform The true rms converter in your meter provides direct accurate measurement of these and other signals Since this DMM is AC and DC coupled refer to the section on Voltage Measurement Techniques for combined AC and DC signal measurements Crest Factor Crest factor range is one of the parameters used to describe the dynamic range of a voltmeter s amplifiers The crest factor of a waveform is the ratio of the peak to the rms voltage In waveforms where the positive and negative half cycles have different peak voltages the higher voltage is used in computing crest factor Crest factors start at 1 0 for a square wave peak voltage equals rms voltage WAVE FORM CREST FACTOR WAVE FORM CREST FACTOR SQUARE WAVE SCR OUTPUT 1 414 to 3 0 WHITE NOISE 3 0 to 4 0 SINE WAVE TRIANGLE AC COUPLED SAWTOOTH PULSE TRAIN Ee SPIKE FREQENCIES 1 414
22. he rectangular pulses would have zero rise and fall time and would be the right angled waveform shown in Figure 3 In practice every waveform has a rise and fall time and looks more like the waveform in Figure 3 When calculating the error caused by the bandwidth of your Instrument we will assume that the rise and fall time 9 equals the slew rate of 1 75 usec To do this we will calculate the values for the theoretical signal with zero rise and fall time then calculate the values for a signal with the same period but with total slope periods equal to 1 75 usec A comparison of the results will show the measurement error due to the finite bandwidth Using Figure 3 for a reference the total rms and DC levels are 3t 21 to t V Total rms A 9 1 VDC A 9 1 Y 3T T Since we can calculate two values to find what your meter measures use the formula VAC rms 4 V total rms V DC Let s look at the waveform in Figure 3 When using your meter to measure the AC component of the signal the display will indicate the rms value of the AC signal riding on the DC level This DC level is the average value of the waveform relation to the baseline The total rms value of the waveform can be calculated using the relationship V Total rms Jvac rms V DC For our example let s use a 10kHz pulse train of 50 usec pulses with a peak value of 1 V Ideally the pulses would have a zero rise time as shown in Figure 3 V Total
23. in the specification limits listed in SPECIFICATIONS Section A calibration cycle of 1 year is recommended to maintain the specifications given in SPECIFICATIONS Section of this manual The test equipment required for both the performance test and the calibration adjustment procedure is listed in Table 3 If the recommended test equipment is not available instruments having equivalent specifications may be used Service Information This DMM is warranted for a period of 1 year upon delivery to the original purchaser Conditions of the warranty are given on the first page of this manual and Service instructions are in the Maintenance Section 16 Cal Procedures NOTE avoid contaminating the pcb with grease from the fingers handle the pcb by its edges or wear gloves If the pcb does become contaminated refer to the cleaning procedure given later in this section Table 3 Recommended Calibration Miis REQUIRED CHARACTERISTICS ne Calibrator DC Volts 0 to 1000V 0 006 AC Volts 100Hz 0 to 750V 0 06 200Hz 0 to 2V x 0 06 1 kHz 0 to 750V 0 06 10 kHz 0 to 100V 0 06 20 kHz 0 to 100V 0 1 9o Fluke 5500 50 kHz 0 to 20V 0 5 DC Current 0 to 2000mA 0 05 AC Current 0 to 19mA 100 Hz x 0 1 96 100 Q 1 kQ 0 01 Resistance 10 100 0 005 1MQ 10MO 0 05 24 shielded cable with a double banana plug at both ends Pomona 2BC 24 Calibration Access Use the
24. ions to avoid misleading results when making measurements in the presence of electronic interference 24 Electrical The electrical specifications apply for an operating temperature of 18 C to 28 C 64 4 F to 82 4 F relative humidity up to 90 and a 1 year calibration cycle DC VOLTS RANGE RESOLUTION ACCURACY for 1 year 200 mV 10uV 2V 100uV 20V 1mV 0 03 of reading 4 digits 200V 10mV 1000V 1000mV Input Impedance 10MO in parallel with 100pF all ranges Normal Mode Rejection Ratio gt 60dB at 60Hz or gt 50dB at 50Hz Common Mode Rejection Ratio gt 90 dB at dc 50Hz or 60Hz 1 unbalanced Common Mode Voltage Maximum 500V DC or peak AC Response Time to Rated Accuracy 1 second maximum Maximum Input 1200V DC or peak AC continuous less than 10 seconds duration on both the 200mV and 2V ranges AC VOLTS True RMS Responding AC or AC DC Voltage Readout Accuracy 9o of reading no of digits between 5 of range and full range INPUT RESOL VOLTAGE Range 20Hz 45Hz 1kHz 2kHz 10kHz 20kHz 50kHz 10mV 200mV 10 200mV 0 1V 2V 100uV 2V 1 0 5 1 2 5 1V 20V imV 20V 15 15 15 15 15 10V 200V 10mV 200V 100V 1000V 100mV 1000V NOT SPECIFIED Typically 3 to 5 digits of rattle will be observed at full scale at 20Hz 25 DC CURRENT RANGE RESOLUTION ACCURACY f
25. ips and sequentially select all ranges starting with the 2000 range The decimal point for each should be as follows Range Display 2000 199 99 2kQ 1 9999 20 kQ 19 999 200 KQ 199 99 2000 1999 9 20 MO 19 999 Display value will show lead resistance Automatic test lead compensation When measuring low resistances test lead resistance interferes with low resistance readings and usually has to be subtracted from resistance measurements for accuracy DIODE MEASUREMENT The five resistance ranges bar with a diode symbol beside the range value have a high enough measurement voltage to turn on a silicon junction These ranges can be used to check silicon diodes and transistors The 2kO range is preferred It is marked with the largest diode symbol CALIBRATION AA WARNING THESE SERVICING INSTRUCTIONS ARE FOR USE BY QUALIFIED PERSONNEL ONLY TO AVOID ELECTRICAL SHOCK DO NOT PERFORM ANY SERVICING OTHER THAN THAT CONTAINED IN THE OPERATING INSTRUCTIONS UNLESS YOU ARE QUALIFIED TO DO 50 Introduction This section contains the maintenance information for this Digital Multimeter This information is divided into service information general maintenance a group of performance tests a calibration adjustment procedure and troubleshooting The performance tests are recommended as an acceptance check when the instrument is first received and should be completed as necessary to verify that your DMM is operating with
26. ith your DMM and to verify that your instrument is functional The LED Display The high contrast 4 1 2 digit LED display is easily read from across the room It can register from 0000 to 19999 counts For ease of discussion the 19999 will be rounded to 20000 in the remainder of this text For example we will refer to the 2V range not the 1 9999V range In all linear functions the decimal point position is determined by the range selected Polarity of the input signal is indicated by a sign at the center of the left side of the LED The sign is disabled in the AC V AC mA and measurement functions The sign may appear in any measurement function but is normally not meaningful when making AC V AC mA and kO measurements You 5 will only get this indication of an energized circuit if the power in the circuit is negative with respect to the COMMON input terminal If the power in the circuit is positive with respect to the COMMON input terminal an erroneous resistance will be displayed If there is any doubt about whether there is energy remaining in the circuit you are reading read the resistance then reverse the test lead positions If the minus sign is displayed in either case the remaining energy must be removed from the circuit before correct resistance readings can be made If you apply an input signal that exceeds the limits of the range selected the LED display will flash All decimal point positions appear in
27. lease contact your distributor SPECIFICATIONS General Temperature Coefficient 0 1 times the applicable accuracy specification per C for 0 C to 18 C and 28 C to 50 C 32 F to 64 4 F and 82 4 F to 122 F Operating Temperature 0 C to 50 C 32 F to 122 F Storage Temperature 10 C to 70 C 14 F to 158 F Relative Humidity Up to 90 0 C to 35 C 32 95 F up to 70 35 C to 50 C 95 122 F except on 2000kO and 20MQ ranges up to 80 0 C to 35 C 32 95 F Environmental Intended for Indoor use Altitude up to 2000m Maximum Common Mode Voltage 500VDC or peak AC low terminal potential with respect to power line ground Size 223 W x 80 H x 329 D mm Weight 2 2Kg Power requirements Line Voltage 105 to 128Vac 47 to 440Hz 210 to 257V AC 47 to 440Hz specified voltage Power Consumption 15W max Safety meets EN61010 1 Cat 1200V Class 11 Pollution degree 2 C EMC Meets EN61326 1 This product complies with requirements of the following European Community Directives 89 336 EEC Electromagnetic Compatibility and 73 23 EEC Low Voltage as amended by 93 68 EEC CE Marking However electrical noise or intense electromagnetic fields in the vicinity of the equipment may disturb the measurement circuit Measuring instruments will also respond to unwanted signals that may be present within the measurement circuit Users should exercise care and take appropriate precaut
28. o 1900 2 3 200 mA 190 00 mA VR204 189 98 to 190 02 AC Volts Calibration On the UUT select AC only 2 V range and connect the V Q terminal to the calibrator HI volts output and COM to the calibrator LO volts output For each step in Table 11 select the listed range program the calibrator for the corresponding UUT input and make the specified adjustment or check Table 11 AC Voltage Calibration Step Range Input Freq Adjust Display Limits 1 2N Short VR501 Less than 0010 2 VR502 1 8995 to 1 9005 2V 1 9000V 400Hz 3 SVC202 203 ADJ to mechanical center 4 a 200V 100 00V 1 kHz SVC201 99 90 to 100 10 b 20V 19 000V 10 kHz SVC202 18 990 to 19 010 5 a 1000v 1000 0v 1 kHz SVC201 999 5 to 1000 5 b 20V 19 000V 10 kHz SVC203 18 990 to 19 010 MAINTENANCE AND REPAIR Changing Input Power Configuration This meter was shipped with power cords and fuses for 117V USA and 230V European operation The initial configuration is for 230V 22 Fuse Replacement This DMM has two fuses The main power fuse is 0 08A or 0 125A 250V for line protection The current measurement fuse is 2A 250V for below 2A current measurements unscrew the mA 2A input jack 117 Line Fuse T 0 125A 250V Bussmann GDB 125mA Littel Fuse 218 125 230V Line Fuse T 0 08A 250V Bussmann GDB 80mA Littel Fuse 218 080 2A Current Input Fuse F 2A 250V Bussmann GMA 2A Littel Fuse 216 002 Maintenance If there appears t
29. o be a malfunction during the operation of the Multimeter the following steps should be performed in order to isolate the cause of the problem Review the operating instructions for possible mistakes in operating procedure Inspect and test the Test Cables for a broken or intermittent connection Inspect and test the fuse See Fuse Replacement Cleaning AACAUTION DO NOT USE AROMATIC HYDROCARBONS OR CHLORINATED SOLVENTS FOR CLEANING THESE SOLUTIONS WILL REACT WITH THE PLASTIC MATERIALS USED IN THE INSTRUMENT Clean the front panel and case with a mild solution of detergent and water Clean dust from the circuit board with clean dry low pressure air 20 psi or less Contaminants can be removed from the PCB using demineralized water and a soft brush remove the display assembly before washing the Main PCB and avoid getting excess amounts of water on the switches Dry with clean dry low pressure air and then bake at 50 to 60 C 122 to 140 F for 24 hours Repair All test tools returned for warranty or non warranty repair or for calibration should be accompanied by the following your name company s name address telephone number and proof of purchase Additionally please include a brief description of the problem or the service requested and include the test leads with the meter Non warranty repair or replacement charges should be remitted in the form of a check a money order credit card with expiration date or a purchase order made pa
30. or 1 Year VOLTAGE BURDEN 200uA 0 01 pA 1mV 1 pA 2mA 0 1 pA 100 mV 1 mA 0 2 of reading 2 digits 20mA 1 pA 10 mV 1mA 200mA 10 pA 1mV 1mA 2000mA 100 pA 200 mV 1A 0 3 of reading 2 digits 20A 1mA 14 mV 1A Overload Protection 5 ranges 200A 2mA 20mA 200mA 2000m4A with fuse protection 20A range no fuse AC CURRENT True RMS Responding AC or AC DC INPUT RESO 10kHz VOLTAGE CURRENT Lurion Range 20Hz 43Hz ees 20kHz BURDEN 200uA OlgA 200 ImV 1nA 1000A 2mA 01A 2mA 100mV 1 mA 1mA 20mA 1 20mA 1 0 5 2 10 mV 1 mA 10mA 200mA 10 200mA 15 15 15 imV 1 mA 100mA 2000mA 100 pA en 200 mV 1A 2000mA 20A 1 20A Not Specified 14mV 1A Typically 3 to 5 digits of drift will be observed at full scale at 20Hz Crest Factor Range Waveforms with a Peak RMS ratio of 1 1 to 3 1 at full scale RESISTANCE FULL SCALE VOLTAGE ACROSS RANGE RESOLUTION ACCURACY for 1 Year UNKNOWN RESISTANCE 000 0 010 0 196 reading 4 digits 0 2V 0 10 2V 20kQ 100 0 1 reading 4 digits 2V 200kQ 10Q 0 2V 2000kQ 100Q 2V 0 25 reading 4 digits 20MQ 1kQ 2V Overload Protection 250V DC AC rms on all ranges 26 Response Time To Rated Accuracy 5 seconds maximum on 20 range 2 seconds maximum on all other ranges Diode Test The 200 2k and 20kQ ranges have enough
31. or due to Burden Voltage E Ep I in96 2100 x B in milli Amps 100 x B M Es Eg Es Eg Examples Es 14V RL 90 IM 1497 mA Eg 100 x x1 0 274 996 of 1 0 0 749V 2000 0 Maximum error in 100 x 149 100 x 13 5 06 14 749 13 251 Increase displayed current by 5 65 to obtain true current Maximum error _ 749x1497 1121 2 in milli Amps 14 749 13251 84 6mA Increase displayed current by 84 6mA to obtain true current RESISTANCE MEASUREMENTS The controls and terminals used to make resistance measurements are located on the front panel The measurement function is selected by pushing the switch to the IN position The colored area enclosing the function switch extends up and to the right enclosing the six range values for the resistance function To select a particular resistance range push the range switch immediately above the value to be measured Connect the test leads red to the V O terminal and black to the COMMON terminal Use the following procedure to familiarize yourself with the resistance function and to see how the range switches affect decimal point position on the LED 15 1 With the test leads held apart select the 2000 range The LED should display an over range indication all digits are flashing 2 Make a firm connection between the probe tips of the test leads The LED should count down to 000 0 3 Maintain a firm contact between the probe t
32. rms SEWER 150 0 5 0 707 3 100 300 vpe 50 0 50 _ 05 100 100 V AC rms 0 707 2 0 5 2 0 50 0 25 0 25 0 5 When the maximum distortion in rise time of 1 75 usec is assumed the signal becomes the isosceles trapezoid waveform shown in Figure 3 In this case VTotal rms 348 25 2 1 75 135 3 100 300 300 ype 48253175 50 5 100 100 V AC rms 4 0 703 2 0 5 2 0 494 0 25 0 244 0 494 Note that the V DC stayed the same So the errors are V total rms 0 6 V AC rms 1 2 VOLTAGE MEASUREMENTS Your DMM can make either linear voltage or AC DC TRUE RMS voltage measurements For both types of measurements plug the black test lead into the COMMON terminal and the red test lead into the V O terminal Linear Voltage Measurements The controls and terminals used for making linear voltage measurements are located on the front panel Starting at the top left is the ACV DCV switch This pushbutton is interlocked with the other two white function selection switches A and If the DCV function switch is in the IN position DCV selected and any other function selection switch is pushed the DCV pushbutton will be released to the OUT position Push the DCV switch to the IN position 10 The light grey area around the ACV DCV switch is extended up and to the right to enclose the five range values of the voltage function P
33. tes present the capabilities and limitations of this instrument and routine operator maintenance instructions Everyone using an DMM should be familiar with the operating notes Input Overload Protection A CAUTION Exceeding the maximum input overload limits can damage your instrument The transient overload protection circuit is intended to protect against short duration high energy pulses The components used limit the protection to approximately five pulses per second for 6kV 10 microsecond pulses and about 0 6 watts average for lower amplitude pulses Each measurement function is equipped with input overload protection Table 1 lists the overload limits for each function Input Connections to Common AA WARNING TO AVOID ELECTRICAL SHOCK AND OR INSTRUMENT DAMAGE DO NOT CONNECT THE COMMON INPUT TERMINAL TO ANY SOURCE OF MORE THAN 500 VOLTS DC OR PEAK AC ABOVE EARTH GROUND This instrument may be operated with the common input terminal at a potential of up to 500V dc or ac peak with respect to earth ground If this limit is exceeded instrument damage or an operator safety hazard may Occur Operating Power This instrument is available in a universal version that uses 117V or 230V AC at 47 to 440Hz Table 1 Maximum Input Signal Limits FUNCTION INPUT SELECTED RANGE SELECTED TERMINALS MAXIMUM INPUT OVERLOAD DC ALL RANGES 1200VDC or Peak AC and V 20V 200V 1000V 1000VDC or Peak AC AC COMMON
34. the display to indicate certain illegal combinations of front panel switch settings For example if you select the DCV function and the 20M range all four decimal points will appear on the display POWER Switch The green POWER switch is located in the right corner of the DMM front panel To turn the meter ON push the POWER button in To turn the meter OFF push the POWER button in DC 1200V 4 AC 1000V 200mV 2 20 200 DO NOT OPERATE INSTRUMENT WITH COVER REMOVED o TO PREVENT FIRE REPLACE FUSH WITH SAME AND RATING MAINS SUPPLY FUSE A ANS SUPPLY FUSE TIT VAC 250 OVAC 70 08 7250 MADE IN TAIWAN o SERIAL Voltage Ohms Diode COM inputs Current mA to 2A and 20A inputs Reading display 0000 to 19999 Power button green Range selection switches The pushbuttons are interlocked with the other ranges Function selection switches The pushbuttons are interlocked with the other two white function selection switches A and Line Power connector Line Voltage selector switch Line Power Fuse AOAO N Figure 1 BDM40 UA Controls 6 OPERATING GUIDELINES To use your multimeter fully there are some additional factors to be considered such as measurement techniques the maximum signal input levels that will not damage your instrument and common applications Operating Notes The operating no
35. ush the range switch immediately above the value to be measured The range selection switches are interlocked in the same manner as the function switches Perform the following procedure 1 If the test leads not connected plug them into your DMM red test lead to the V O terminal and black to the COMMON terminal 2 Selectthe 0 2V range 3 Pushthe function switch to the DCV position 4 With the POWER switch set to the OFF position connect your DMM to a line power outlet rated at the operating voltage and frequency of your instrument Keep the probe tips apart and not connected to a circuit 5 Push the POWER switch to the ON position The LED should count down rapidly to a reading of lt 0020 6 Select the ACV and 1000V range A A WARNING LOCAL LINE VOLTAGE IS MEASURED IN THE FOLLOWING STEP BE CAREFUL NOT TO TOUCH THE PROBE TIPS WITH YOUR FINGERS OR TO ALLOW THE PROBE TIPS TO TOUCH EACH OTHER 7 Insertthe probe tips of the test leads into the slots of a power outlet The LED should display the true local line voltage 8 Push the DCV push button switch The LED should display near zero volts but there may be some residual dc voltage on the power line due to non linear loads such as SCR light dimmers 9 Remove the test leads from the line power outlet Converting voltage measurements Your instrument is one of a family of DMMs that actually measure the true rms value of an AC or AC DC signal This is a fe
36. yable to Amprobe Test Tools In Warranty Repairs and Replacement All Countries Please read the warranty statement and check your battery before requesting repair During the warranty period any defective test tool can be returned to your Amprobe Test Tools distributor for an exchange for the same or like product Please check the Where to Buy section on www amprobe com for a list of distributors near you Additionally in the United States and Canada In Warranty repair and replacement units can also be sent to a Amprobe Test Tools Service Center see below for address 23 Non Warranty Repairs and Replacement US and Canada Non warranty repairs in the United States and Canada should be sent to a Amprobe Test Tools Service Center Call Amprobe Test Tools or inquire at your point of purchase for current repair and replacement rates In USA In Canada Amprobe Test Tools Amprobe Test Tools Everett WA 98203 Mississauga ON 147 1X9 Tel 877 AMPROBE 267 7623 Tel 905 890 7600 Non Warranty Repairs and Replacement Europe European non warranty units can be replaced by your Amprobe Test Tools distributor for a nominal charge Please check the Where to Buy section on www amprobe com for a list of distributors near you European Correspondence Address Amprobe Test Tools Europe P O Box 1186 5602 BD Eindhoven The Netherlands Correspondence only no repair or replacement available from this address European customers p
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