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Instruction and Service Manual

1. 0 2 Table 5 3 Analog Meter Calibration Performance Table im j 0 Re 1 Re 40 8 0 50 0 OG pO OY 02 J 9 0 90 O Table 5 4 Isolated Output Calibration Performance Table Range VDC Applied VDC Accuracy Limits VDC 27 15000 to 26 85000 m Table 5 5 Offset Voltage Calibration Performance Table 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 13 TEGAM Section V Maintenance and Servicing TROUBLESHOOTING WARNING Dangerous voltages from the ac power line test instruments and measured source can be present when troubleshooting the avm 2000 Exercise proper safety precautions CAUTION Follow esd electrostatic discharge procedures when handling the AVM 2000 printed circuit boards and their components NOTE The AVM 2000 setup processes must be performed after making any repairs Depending on the observed symptom probable areas for investigation or repair in the AVM 2000 are indicated Refer to disassembly instructions to gain access to the indicated areas as well as reassembly instructions Refer to the theory of operation for the affected section The parts layout test points and control adjustment locations and schematics are found in parts list When replacing any soldered component on one of the printed circuit boards particularly the Isolated Analog Section m
2. 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 8 TEGAM Section Il Preparation for Use and Installation Unpacking amp Inspection Each AVM 2000 is put through a series of electrical and mechanical inspections before shipment to the customer Upon receipt of your instrument unpack all of the items from the shipping carton and inspect for any damage that may have occurred during transit Report any damaged items to the shipping agent Retain and use the original packing material for reshipment if necessary Upon Receipt inspect the carton for the following items Model AVM 2000 RF Power Meter AC Power Module Rechargeable Battery Input Terminal Shield GUARD to LO Nickel Plated Shorting Link 2 UF Filter Block Mounted on Dual Banana Jack Technical Operation and Maintenance Manual Mounting The AVM 2000 is a free standing bench instrument housed in a protective metal enclosure A single unit may be mounted in a standard 19 inch rack using a conventional rack shelf Bail front feet allow the user to tilt the instrument for optimal viewing Use in Proper Environment Normal calibration laboratory practice dictates that the environment should be closely controlled This will minimize errors introduced by temperature and humidity changes A nominal temperature of 15 30 C provides a good working condition CAUTION The AVM 2000 has a specified ambient temperature range 15 30 C Operating b
3. 4 Connect the Digital Multimeter HI and LO INPUT terminals to AVM 2000 rear panel and terminals observe polarity 5 Set the Digital Multimeter FUNCTION for DCV and AUTO range If AVM 2000 LCD OFST indication is not 00 000 00 uV using the INPUT OFFSET knob to select the place value and the OFFSET WV A buttons to select the numerical value set OFST indication to 00 000 00 uV 6 Press AVM 2000 INPUT OFFSET knob until V is displayed Press and hold AVM 2000 INPUT OFFSET knob for approximately 5 seconds 7 Press AVM 2000 INPUT OFFSET knob until I is displayed Press and hold AVM 2000 INPUT OFFSET knob for approximately 5 seconds 8 Press AVM 2000 INPUT OFFSET knob until a padlock symbol is displayed in the lower right of the LCD 9 If required press AVM 2000 OPERATE ZERO button to select IMPEDANCE ZERO as indicated on AVM 2000 LCD 10 Press and hold AVM 2000 RANGE knob for approximately 5 seconds until AVM 2000 LCD indicates METER OFFSET 11 Using AVM 2000 OUTPUT LEVEL knob adjust AVM 2000 meter for a zero indication 12 Turn AVM 2000 RANGE knob one step clockwise and AVM 2000 LCD readout will indicate METER GAIN 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 4 TEGAM Section V Maintenance and Servicing 13 14 15 16 L7 18 19 NOTE Using AVM 2000 OUTPUT LEVEL knob adjust AVM 2000 for a 10 full scale positive indication Turn AVM 2000 RAN
4. The AVM 2000 is delivered with an AC Power Module for operation from 120 10 VAC 60 Hz If the AVM 2000 is to be operated from a 240 10 VAC 50 400 Hz power source or the input power range needs to be changed from a previous selection an alternative AC Power Module is required Contact TEGAM for a selection of input Power Modules CAUTION DO NOT APPLY POWER TO THE INSTRUMENT BEFORE READING THIS SECTION Check the Power Cord Make sure the power cord supplied with the Model AVM 2000 is not frayed broken or cracked A damaged power cord is a fire and electrical hazard If the power cord is damaged it should be replaced Use the Proper Fuse To avoid fire hazard use only the correct fuse type as specified for the AC power supply in the unit The correct fuse for the AVM 2000 is a 1 1 4A 3AG Slow Blow Fuse The fuse is located just below the power cord socket Before replacing the fuse place the Model AVM 2000 front panel power switch to the OFF position and remove power cord on the back of the Model AVM 2000 To replace the fuse gently slide out the fuse drawer Remove the old fuse and snap a new one into the fuse holder Reinstall the fuse by simply pushing the fuse drawer back into its original position The fuse drawer should snap into place Grounding the Equipment ISOLATED OUTPUT Two Red and Black binding posts with banana sockets 4mm are provided to connect the AVM 2000 s ISOLATED OUTPUT to an external device A third
5. A Locations OR 800 666 1010 United States Only The RMA number is unique to your instrument and will help us identify you instrument and to address the particular service request by you which is assigned to that RMA number Of even importance a detailed written description of the problem should be attached to the instrument Many times repair turnaround is unnecessarily delayed due to a lack of repair instructions or of a detailed description of the problem This description should include information such as measurement range and other instrument settings type of components being tested are the symptoms intermittent conditions that may cause the symptoms has anything changed since the last time the instrument was used etc Any detailed information provided to our technicians will assist them in identifying and correcting the problem in the quickest possible manner Use a copy of the Repair and Calibration Service form provided on the next page Once this information is prepared and sent with the instrument to our service department we will do our part in making sure that you receive the best possible customer service and turnaround time possible 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 6 TEGAM EXPEDITE REPAIR amp CALIBRATION FORM Use this form to provide additional repair information and service instructions The Completion of this form and including it with your instrument
6. Below is a summary of these precautions Terms in This Manual CAUTION statements identify conditions or practices that could result in damage to the equipment or other property WARNING statements identify conditions or practices that could result in personal injury or loss of life Terms as Marked on Equipment CAUTION indicates a personal injury hazard not immediately accessible as one reads the marking or a hazard to property including the equipment itself DANGER indicates a personal injury hazard immediately accessible as one reads the marking Symbols As Marked in This Manual This symbol denotes where precautionary information may be found As Marked on Equipment Frame or Chassis Terminal em Earth Ground Terminal Alternating Current 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com TEGAM Purpose and Function The AVM 2000 is a multi range analog DC Voltmeter Nullmeter It has 21 bipolar ranges from 100 nanovolts full scale to 1000 volts full scale in a 1 3 10 sequence The AVM 2000 functions either as an isolated null detector or as an isolated analog voltmeter Key functions of the AVM 2000 The AVM 2000 is a freestanding bench instrument housed in a protective metal enclosure A single unit may be mounted in a standard 19 inch rack using a conventional rack shelf Bail front feet allow the user to tilt the instrument for optimal viewing Voltage readings are displaye
7. I Introduction Purpose and functions s essssssssusnnsessnssnnuennsenunnusnnunsnsanussnnusnnsnsnnnnnnnan 1 1 CASO WIISGS asco cag UIT 1 1 Performance characteristics eseeeeseseeeeee enne nena nnn 1 2 Environmental infOrmation ccccccccccsccsssenetreeceeeccuseeeeetesteseguaaannesesegs 1 3 Power and utility information eeeeeehh nennen nnnm nnn 1 4 List of items Tur nisligQ ss vaa dex ixi krEE hbtRD Gub Ce XAR DRE EXTERN ERA RXYRAN E FETEEYRSP u EE 1 5 List of additional items required for operation and maintenance 1 5 Preparation for calibration or repair and shipping eeeeeeeeeeee 1 6 Expedite Repair FOIIYssisvisaxessvwisssaa es dxetrbridasebasrid vuwil era kePrsrurErrk vedi era 1 7 Wabrgne Irormetiollasssse esed ERPEKEE SM d ETEA d dTX DU NFEIU VEHI WINE EPI EVENTS 1 8 TEGAM contact Inftorrmeatloll eoir dusk cadi XT Evi dran rd eed exl eC EXP daa 1 8 II Preparation for Use and Installation Unpacking amp IpnSBectlOlksbsssesedsesadussaat s ovin Ux I Nau Ta US nU sm Md SE 2 1 Recommended Operating Environment esses nnne 2 1 III Principles of Operation AVMs2000 measurement DEOCGSS caesus derdaxene ate RinerRi EiGserhr ii da f v EXas e iPss 3 1 IV Operating Instructions Front Panel DISDIAYS aeesvcps qibemenbHER via tiers PPS PIN PV ERIT SEEN ET Pd tients US PbsrDI MEA 4 1 Front Panel ControlS ocsessdsasxkasaiet usado Re Pih Ray i ux Ss iota pbi are r
8. Yellow binding post connected to the AVM 2000 case which may be connected to earth ground via other connections to the instrument The ISOLATED OUTPUT red and black binding posts are electrically isolated from the HI and LO input terminals The signal level present at the ISOLATED OUTPUT is adjustable via the OUTPUT LEVEL control from 0 5 V to 1 5 V full scale for the RANGE selected The ISOLATED OUTPUT zero reference is adjusted during the Setup mode using the OUTPUT LEVEL control WARNING To avoid electrical shock or other potential safety hazards plug the power cord into a properly wired receptacle before using this instrument The proper grounding of this instrument is essential for safety and optimizing instrument operation WARNING Applying more than 1100 Volts across the input terminals or from either input terminal to common or ground results in instrument damage not covered by the warranty NOTE Rapid changes in input voltage potentially can result in voltages well in excess of 1100 Volts due to reactive effects in the supply circuit such induced voltage may damage the instrument AN 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 4 TEGAM Items Included with the AVM 2000 AC Power Module PS 107 Rechargeable Battery BA 105 Input Terminal Shield 0600 081 GUARD to LO Nickel Plated Shorting Link J 5 2 uF Filter Block Mounted on Dual Banana Jack 0600 090 Technical
9. and LO terminals to AVM 2000 front panel HI and LO terminals respectively Using AVM 2000 FILTER V A buttons set FILTER to 2 0 Sec Using AVM 2000 RANGE knob select the first AVM 2000 range listed in the Range column of Table 5 1 and set IMPEDANCE to 10 MQ using the INPUT MQ button not required on the 1000 V range Manually Zero Range of AVM 2000 a Manual Range Zero of the AVM 2000 i Set the Meter Calibrator for zero VDC and set the OPR STBY switch to OPR ii If required select AVM 2000 IMPEDANCE ZERO function using the OPERATE ZERO button iii Press AVM 2000 INPUT OFFSET knob until a V indication is displayed iv Adjust AVM 2000 INPUT OFFSET knob for a zero indication on AVM 2000 analog meter v Press AVM 2000 OPERATE ZERO button vi Adjust AVM 2000 INPUT OFFSET knob for a zero indication on AVM 2000 analog meter vii Press AVM 2000 INPUT OFFSET knob until a padlock symbol is displayed in the lower right of the LCD viii Set the Meter Calibrator OPR STBY switch to STBY Set the Meter Calibrator for the first positive value listed in the Applied column of Table 5 1 and set the OPR STBY switch to OPR Edit the Meter Calibrator output amplitude until AVM 2000 analog meter indicates full scale The Meter Calibrator must indicate within the corresponding positive values listed in the Limits column of Table 5 1 Set the Meter Calibrator OPR STBY switch to STBY 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466
10. at the other end of the cable to eliminate a defective interconnection cable 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 14 TEGAM Section V Maintenance and Servicing Symptom AVM 2000 does not operate with line power and internal rechargeable battery does not charge or the battery charge indicator continuously displays ERR AC Power Module is not plugged in or is not connected Action Check the connections at both ends Power Supply Subsystem fuse is blown Action Replace the fuse with one of the same type and value If the Power Supply Subsystem fuse continues to blow the Power Supply Subsystem or one of the subsystems it feeds is defective Action Disconnect the balance of the AVM 2000 from the Power Supply Subsystem by removing connector J4 e If the fuse continues to blow disconnect the battery J3 and measure the open circuit battery voltage If the open circuit battery voltage lies between 5 3 and 7 0 volts the Power Supply Subsystem is defective Action replace the Power Supply Subsystem If the open circuit battery voltage is substantially below 5 3 volts the battery has one or more shorted cells Action Replace the battery If the fuse does not continue to blow the problem lies with either the Front Panel or Isolated Analog Subsystem Action Disconnect the Isolated Analog Subsystem from the Front Panel Subsystem by unplugging connector J2 of the Front Panel Subsy
11. from any non measurement related connections to other apparatus recorders chargers etc is a good way to isolate such problems If the problem persists and all indications point to a problem with the AVM 2000 the problem lies with the Isolated Analog Subsystem Action Replace the Isolated Analog 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 18 TEGAM Section VI Reprogra mming Total Instrument Reset TIR If the instrument basic functions do not seem to operate ranges cannot be selected meter is always pegged the meter is unresponsive to ZERO functions etc a total instrument reset may be needed Before this action is performed ensure a reasonable level of battery charge is shown on the battery charge level indicator at least 2 scale NOTE A TIR does not correct problems with the instrument Front Panel Subsystem Such problems are indicated by incomplete LCD indications missing or partial characters for example If this is the case proceed to TROUBLESHOOTING To perform a total instrument reset Turn the instrument OFF Allow the instrument to remain off for at least 5 minutes with the power adaptor disconnected or any source of charging current disconnected Reconnect the power adaptor Turn the instrument ON Verify the problem continues to exist Depress and hold the RANGE control until the LCD reads METER OFFSET Simultaneously depress and then release both FILTER
12. full scale INPUT IMPEDANCE 1 10 100 MQ 1 GQ or ZERO Shorted input OFFSET 30 000 00 uV in 0 01 uV steps BATTERY STATUS Vertical bar graph showing O Full Charge VARIABLE CONTROL LOCK Status of variable control locks FILTER Filter times from 0 1 s to 100 s in 1 2 5 sequence Power ON indication is also on the LCD display indicating the amount of battery life remaining The LCD blinks CHARGING if the instrument is connected to a charging source with power turned OFF The battery graph indicates ERR if the battery voltage is abnormally low with charging current applied Analog Display Voltage readings are displayed on a taut band 4 1 2 inch zero center mirror backed meter with dual scales 0 3 or O 10 The scale used depends on the range selected AVM 2000 NULL METER Figure 4 1 AVM 2000 Front Panel 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 1 TEGAM Section IV Operating Instructions Front Panel Controls Power Pushbutton Push ON Push OFF RANGE PUSH FOR MENU Rotary Control Pushbutton This is a multi function button and should be thoroughly understood prior to operating any other controls on the AVM 2000 Range In the default position meaning the rotary button was not pressed only rotated the rotary control button selects one of 21 full scale voltage ranges 100 nV 300 nV 1 uV 3 UV 10 UV 30 UV 100 UV 300 LUV 1 mV 10 mV 30
13. of noise thermal drifts and other undesired signals that tend to be of a single polarity Further averaging of these responses also minimizes the impact of drift Amplification of the input signal occurs in a low noise low drift multi stage programmable gain amplifier The input amplifier housing is shielded to ensure minimal impact from external electro magnetic signals and short term temperature changes in the operating environment The amplifier components are chosen to ensure Johnson Noise and other similar noise contributors fall below an equivalent noise resistance of 25Q Early stages of the input amplifier are provided with basic filtering that permits the amplifier to maintain its DC performance characteristics with the simultaneous application of a line frequency 50 Hz or 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 3 1 TEGAM Section III Principles of Operation greater signal up to 80 dB greater than the signal being measured Precise and highly stable offset current is also applied to the input amplifier via a 16 bit DAC whose output value is set by the front panel INPUT OFFSET control The output of the multi stage amplifier is applied to the input of a precision 24 bit analog to digital converter This high precision high stability analog to digital converter samples the input signal including input noise many times per second Various filtering averaging algorithms are applied to
14. pin power cable J1 the 3 pin rear panel J4 and meter J5 connections from the front panel board as well as the 10 pin Isolated Analog Subsystem connector J2 from the front panel board 5 Using a hex key loosen the set screws holding the three front panel knobs on their respective shafts and remove the knobs Additionally the range control is secured to the front panel by a hex nut and flat washer that must be removed An internal tooth lock washer is located on the range control bushing 6 With the front panel board completely disconnected from the balance of the instrument remove the two screws that fasten the base plate to the front panel 7 Remove the captivating screws lock washers from the mounting studs and remove the front panel board from the front panel 8 Installation of a front panel board is performed by reversing the order of the above removal steps Isolated Analog Subsystem 1 Make sure the POWER switch is in the OFF out position 2 Disconnect the AC Power Module or other charging source from the AVM 2000 3 Remove the 8 screws left and right sides of the instrument case that attach the top cover to the front and rear panels Slide the top cover vertically from the instrument 4 With the top cover removed disconnect the 3 pin battery cable J3 from the power supply board 5 Disconnect the 10 pin cable coming from the Isolated Analog Subsystem to the front panel J2 6 Disconnect the 10 pin cable coming
15. pins the ISOLATED OUTPUT binding posts and the fuse wires from the power supply board 7 Remove the power transistor cable J2 8 Remove the captivating nuts lock washers from the mounting studs and remove the power supply board from the back panel 9 Ifthe power transistor is to be replaced remove the transistor by first removing the retaining nut from the mounting stud Clean any residual heat sink compound from the back panel with denatured alcohol and reapply fresh compound prior to the installation of the new transistor Be sure a new isolating shoulder washer is placed over the stud and centered in the power transistor s mounting hole before the nut is tightened CAUTION Many connectors are similar in appearance When re assembling the instrument be sure connector and jack numbers match and those connectors are installed correctly 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 1 Section V Maintenance and Servicing Front Panel Subsystem 1 Make sure the POWER switch is in the OFF out position 2 Disconnect the AC Power Module or other charging source from the AVM 2000 3 Remove the 8 screws left and right sides of the instrument case that attach the top cover to the front and rear panels Slide the top cover vertically from the instrument 4 With the top cover removed disconnect the 3 pin battery cable J3 from the power supply board At the front panel disconnect the 10
16. switch and control knobs are on tight If they are loose tighten with the proper size Allen wrench or a small flat blade screw driver as appropriate Disassembly and Re Assembly Make sure the AC Power Module or any other source of charging current is disconnected and removed from the AVM 2000 before any disassembly or reassembly of the instrument The reader should become familiar with drawings parts identification parts layout and other mechanical information CAUTION The battery must be disconnected as the first step in any disassembly process CAUTION Follow ESD ELECTROSTATIC DISCHARGE Procedures when handling the AVM 2000 printed circuit boards and their components POWER SUPPLY SUBSYSTEM 1 Make sure the POWER switch is in the OFF out position 2 Disconnect the AC Power Module or other charging source from the AVM 2000 3 Remove the 8 screws left and right sides of the instrument case that attach the top cover to the front and rear panels Slide the top cover vertically from the instrument 4 With the top cover removed disconnect the 3 pin battery cable J3 10 pin power cable J4 and the 3 pin ISOLATED OUTPUT interconnect cable J1 from the power supply board to facilitate access 5 With the battery and power supply board completely disconnected from the balance of the instrument remove the two screws that fasten the base plate to the rear panel 6 With the back panel free from the case unsolder the charging jack
17. 000 INPUT OFFSET knob to select the place value and the OFFSET WV A buttons to select the numerical value set AVM 2000 OFST indication for 27 000 00 pV Using AVM 2000 RANGE knob select the 3 mV range Using AVM 2000 INPUT OFFSET knob to select the place value and the OFFSET WV A buttons to select the numerical value adjust TI OFST value for a null indication on AVM 2000 analog meter The AVM 2000 OFST value must be within 27 150 00 to 26 850 00 UV Using AVM 2000 RANGE knob select the 1 mV range Repeat steps 7 and 8 Using AVM 2000 RANGE knob select the 30 mV range Using AVM 2000 INPUT OFFSET knob to select the place value and the OFFSET WV A buttons to select the numerical value set AVM 2000 OFST indication for 00 000 00 uV Set the Meter Calibrator for 27 mV DC Using AVM 2000 INPUT OFFSET knob to select the place value and the OFFSET WV A buttons to select the numerical value set TI OFST indication for 27 000 00 pV Repeat steps 6 through 12 using positive values in step 8 Set the Meter Calibrator OPR STBY switch to STBY Set all POWER switches to OFF STBY disconnect and secure all equipment 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 12 Section V Maintenance and Servicing stu ft 0 980 tO 1 020u 3u__ 3_ 2 940 to 3 0000 et OSRE J 1 Ref 1 REF 1 08 0 6 00 0 0p o 00000000 0 48 2 J
18. 6110 www tegam com 5 7 TEGAM Section V Maintenance and Servicing 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Repeat steps 5 through 8 for the first negative value listed in the Applied and Limits column of Table 5 1 Repeat steps 3 through 9 for each remaining value listed in the Range and Applied columns of Table 5 1 Table 5 1 Using AVM 2000 RANGE knob select AVM 2000 1 V range Perform Manual Range Zero of AVM 2000 leave the Meter Calibrator in OPR Press the Meter Calibrator OFFSET button Set the Meter Calibrator for 1 VDC Edit the Meter Calibrator output amplitude until AVM 2000 analog meter indicates full scale Press the Meter Calibrator SCALE button Set the Meter Calibrator for 0 8 VDC and edit the output amplitude until AVM 2000 analog meter indicates this value The LinError indication on the Meter Calibrator display rounded to the nearest whole percentage must be within 2 to 2 Repeat steps 17 and 18 for 0 6 0 4 and 0 2 VDC Press the Meter Calibrator SCALE button setting the function off Repeat steps 14 through 19 with negative applied voltages Set the Meter Calibrator OPR STBY switch to STBY and press the SCALE and OFFSET buttons setting the functions off Using AVM 2000 RANGE knob select AVM 2000 3 Volt range Repeat Manual Range Zero of AVM 2000 leave the Meter Calibrator in OPR Press the Meter Calibrator OFFSET
19. FFSET Rotary Control Pushbutton until the amp closed padlock changes to V Dial the INPUT OFFSET Rotary Control Pushbutton until zero is attained on the analog display Dial the Range Rotary Control Pushbutton changing the range to 3 uV and repeat step 7 and repeat on every range up to and including 10 V n d 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 7 TEGAM Section V Maintenance and Servicing Maintenance No regular maintenance is required other than to keep the internal battery charged Calibration Verification should be performed yearly or as required The exterior of the Model AVM 2000 should be cleaned periodically as is necessary using a soft cloth dampened with a mild non abrasive water soluble detergent and then rinsed with a water dampened soft cloth DO NOT use alcohol solvents harsh chemicals or abrasive materials to clean the AVM 2000 Meter or other plastic knobs and connectors Clean the AVM 2000 Meter exterior face using a soft cloth dampened with a mild non abrasive water soluble detergent and then rinse with a water dampened soft cloth Wipe dry with another soft cloth DO NOT use common paper towel products in place of a soft cloth as some brands may contain fibers which could scratch the AVM 2000 Meter DO NOT use alcohol solvents harsh chemicals or abrasive materials to clean the AVM 2000 Meter Periodically inspect the AVM 2000 to make sure all the
20. GE knob one step clockwise and AVM 2000 LCD readout will indicate METER GAIN Using AVM 2000 OUTPUT LEVEL knob adjust AVM 2000 for a 10 full scale negative indication Turn AVM 2000 RANGE knob one step clockwise and AVM 2000 LCD readout will indicate OUTPUT OFFSET Using AVM 2000 OUTPUT LEVEL knob adjust for a zero 3 mV indication on the Digital Multimeter Turn AVM 2000 RANGE knob one step clockwise If AVM 2000 LCD indicates ZERO RANGE simultaneously press OFFSET WV A buttons so that AVM 2000 LCD readout indicates ZERO ALL otherwise proceed to next step Auto Zero is a very time consuming process that does not always yield perfect results due to the large number of ranges The user may want to skip to manual zero process CAUTION Do not turn AVM 2000 RANGE switch clockwise again with the short attached AVM 2000 could be damaged if a reference voltage is selected with a short attached 20 21 22 23 24 25 26 Connect a short between AVM 2000 HI and LO terminals Press AVM 2000 OUTPUT LEVEL knob TI LCD will indicate a blinking ZERO ALL When the ZERO ALL indication stops blinking the zeroing process is complete approximately 10 minutes Press AVM 2000 RANGE knob Press AVM 2000 OPERATE ZERO button to select IMPEDANCE a resistance value not ZERO as indicated on AVM 2000 LCD Press and hold AVM 2000 RANGE knob for approximately 5 seconds until AVM 2000 LCD indicates METER OFFSET Tu
21. HI red and LO black terminal of the AVM 2000 NOTE A zero may be accomplished while in a test configuration such as a Kelvin Varley Divider calibration For this type of zero it is important to insure the voltage source is connected and power output is set to O and the output is off This will give you a zero through the entire configuration rather than simply shorting the AVM 2000 at the input Procedure for Zeroing the AVM 2000 in ZERO mode 1 Power On the AVM 2000 and allow for normal instrument warm up 2 Set the Filter to 2 0 sec a Press the Filter push button s until the display shows 2 0 sec b Other Filter ranges may be used but 2 0 sec is the optimal for zeroing 3 Select what Ranges need zeroing NOTE Knowing what ranges to zero can reduce your procedure time exponentially For example to achieve sub part per million results while calibrating a 10 V source the operator would calibrate fro 10 V to 1 uV There would really be no need to calibrate the ranges above 10 V or below 1 pV 4 Place the AVM 2000 in ZERO mode a Press the OPERATE ZERO button until the ZERO appears in the display b Other impedance settings are ignored at this point Dial the Range Rotary Control Pushbutton to the range on the display changes to 1 yV Press the INPUT OFFSET Rotary Control Pushbutton until the amp closed padlock changes to V Dial the INPUT OFFSET Rotary Control Pushbutton until zero is attained on the analog display D
22. Instruction and Service Manual AVM2000 900 Table 1 2 AVM 2000 Packing List Additional items required for operation and maintenance Precision voltage and current source 0 to 1000 Volts DC amp AC RMS and 10 pA 1 A DC such as Fluke model 5100 or 5720 Multi Product Calibrator Precision DMM with range of 0 to 1000 V DC and AC RMS such as Fluke model 8508A Keithley 2002 or Agilent 3458A Oscilloscope such as Tektronix model TDS 1000 Environmental chamber capable of housing the AVM 2000 with ability to regulate temperature from 10 C to 35 C 0 1 C such as Thermotron model S 5 5 3800 Megohmmeter such as PPM model R1M A Low thermal EMF shielded test leads solid copper wire or solid copper wire with gold plated spade terminals Pure copper shorting strap 10 mQ 10 A shunt 0 1 25 Q resistor 4 Watt 1 30 Q resistor V4 Watt 1 10 kQ resistor 4 Watt 1 1 MQ resistor 4 Watt 1 10 MQ resistor Watt 2 100 MQ resistor V4 Watt 2 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 5 TEGAM Preparation For Calibration Or Repair Service Once you have verified that the cause for the AVM 2000 malfunction cannot be solved in the field and the need for repair and calibration service arises contact TEGAM customer service to obtain an RMA Returned Material Authorization number You can contact TEGAM customer service via the TEGAM website www tegam com or by calling 440 466 6100
23. T Make sure the Meter connector J5 see page 49 is properly seated and that a voltage is being developed across the meter terminals approximately 35 mV for a full scale deflection If a voltage is being developed and there is no meter movement the meter movement is defective Action Replace the meter movement NOTE If the meter movement requires replacement the replacement includes special setup instructions required to ensure proper system linearity If there is no voltage present across the meter terminals the Front Panel Subsystem is defective Action Replace the Front Panel Subsystem Symptom Output on AVM 2000 Meter but no signal at ISOLATED OUTPUT Check for the appropriate DC signal i e a scaled 1 volt for full scale meter deflection at connector J4 pin 2 or TP8 of the Front Panel Subsystem If the signal is present at J4 pin 2 or TP8 the output cable is defective Action Replace the output cable If no signal is present at J4 pin 2 or TP8 the Front Panel Subsystem is defective Action Replace the Front Panel Subsystem Symptom Poor 60 Hz AC noise rejection Most frequently poor 50 60 Hz noise rejection is a function of improper measurement configuration Action Carefully check all cable routing ground connections sequencing of connections etc NOTE Ground loops i e multiple paths for ground currents can be a significant source of undesirable interfering electrical noise Disconnecting the instrument
24. TEGAM AVM 2000 HIGH SENSITIVITY ANALOG DC VOLTMETER NULLMETER Instruction and Service Manual PN AVM2000 900 Publication Date October 2010 REV B 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com TEGAM TEGAM is a manufacturer of electronic test and measurement equipment for metrology calibration and production test We also provide repair calibration and other support services for a wide variety of test and measurement equipment including RF power sensor calibration systems RF attenuation measurement systems ratio transformers arbitrary waveform generators micro ohmmeters LCR meters handheld temperature calibrators thermometers humidity and temperature control devices and more TEGAM also repairs and calibrates test and measurement equipment formerly manufactured by Electro Scientific Industries ESI Gertsch Keithley Instruments Lucas Weinschel and Pragmatic Instruments A complete list can be viewed on our Product Service Directory at www tegam com For more information about TEGAM and our products please visit our website at www tegam com or contact one of our customer service representatives at sales tegam com or 800 666 1010 10 Tegam Way Geneva Ohio 44041 Telephone 440 466 6100 Fax 440 466 6110 E mail sales tegam com 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com www fegam com Table of Contents Section Page
25. V and below instrumentation amplifier with isolated output A front panel knob allows operator adjustment of the isolated output amplitude The Front Panel Subsystem control circuits consist of a microprocessor LCD 6 pushbuttons and 3 rotary encoders The microprocessor continuously scans the switches and rotary encoders to detect any changes It also regularly updates the LCD with the current AVM 2000 status as selected by the user with the pushbuttons and rotary encoder The microprocessor regularly poles the Isolated Analog Subsystem via a high speed optically isolated serial communications bus The Isolated Analog Subsystem responds supplying the results of the current analog to digital conversions of the applied input signal In addition to polling the Isolated Analog Subsystem Front Panel Subsystem communications include information such as current RANGE FILTER OFFSET OPERATE ZERO ZIN and ZERO selections When operated in the setup mode special menu on the LCD selected by depressing the Range Control the microprocessor communications are modified to contain special requests such as ZERO GAIN and setting the 2 667 volt reference 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 3 2 TEGAM Section IV Operating Instructions Front Panel Displays LCD Display Instrument operating status is indicated on the front panel LCD Information displayed includes RANGE 21 Ranges from 100 nV to 1 kV
26. ake sure to clean completely away any solder flux residue The AVM 2000 s operation is highly dependent on internal software based functions within the two microprocessor based subsystems Any component level troubleshooting requires access to software development tools and the accompanying interfaces to connect the software development system to the two microprocessors Troubleshooting in this manual is limited to identifying problems with the instrument s major subsystems which can be returned to PPM for repair exchange if a defective subsystem is identified Techniques are presented below to identify a need to replace exchange one of the following AC Power Module Rechargeable Battery Power Supply Subsystem Front Panel Subsystem Isolated Analog Subsystem Meter Movement Interconnection Cables NOTE Failure to keep the Isolated Analog Subsystem Board clean of contaminants may compromise the performance of the AVM 2000 Avoid touching the electrical surfaces of this board unless wearing clean gloves Troubleshooting Tip Always check signals voltages at BOTH ends of the indicated cable connector If the indicated signal is present at one end of the cable but not at the other a defective cable is indicated rather than a defective subsystem In the steps below only one end of the cable is called out in each step If the indicated positive results are not obtained in the step always check the like connection i e red wire 5 pin etc
27. bd ita Lc db irons 4 2 Normal Operat oT TRE TEM 4 5 Setting Zero PrOCCGUIPGscissccidntccinsateerstssoxassaeetisarnsaneindactdaniaainatedseinaan 4 6 V Maintenance and Servicing Maintenance ssssesesesese seen nemacsasaseseskasasasasesessu naa asas uasa nn 5 1 Disassembly and Re Assembly cceessseeeee nennen nnne nnn nnn 5 1 Calibration VerittcdblOllroeescid aiwenpds pav bE ud Vduad qEUa DE 1E dd EE saca 9d a icbuu dpa dara Ao dd 5 4 eese rETNTETNITTURNTIMET mmSmFCBtBtmttt 5 7 WOUE NOOI sss ux TER PF rPUrIA Nau NEM IIa FEMINIS VEI SIE DIS 5 14 VI Reprogramming Total Instrument Reset TIR 22aeseaxxeunva citus 3a xi aS VIDEOR OU UE YR DUC KX R a OA 6 1 MEMO ANZAO eeraa s 6 1 VII Preparation for Shipment Returning power meter for serviCe s ssssssrsrsrsrsrsrrrrnrnrnrnrnrnrnrsnnnnnnnnn 7 1 Repacking for SNIDIMENL viicusssenctasinncacesseisttianidativessrsediannetedeesadoanentesenne 7 1 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com TEGAM www tegam com VIII Storage Temperature and other environmental limitations cccceeeeeeeeeeeeeeeeees 8 1 Safety Information amp Precautions The following safety information applies to both operation and service personnel Safety precautions and warnings may be found throughout this instruction manual and the equipment These warnings may be in the form of a symbol or a written statement
28. button 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 8 TEGAM Section V Maintenance and Servicing 26 2 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Set the Meter Calibrator for 3 VDC Edit the Meter Calibrator output amplitude until AVM 2000 analog meter indicates full scale Press the Meter Calibrator SCALE button Set the Meter Calibrator for 2 VDC and edit the output amplitude until AVM 2000 analog meter indicates this value The LinError indication on the Meter Calibrator display rounded to the nearest whole percentage must be within 2 to 2 Repeat steps 29 and 30 for 1 VDC Press the Meter Calibrator SCALE button setting the function off Repeat steps 26 through 31 with negative applied voltages Set the Meter Calibrator OPR STBY switch to STBY and press the SCALE and OFFSET buttons setting the functions off Disconnect test setup Connect equipment as follows a Connect AVM 2000 HI to Current Shunt Potential and the LO to the Potential b Connect the Meter Calibrator HI to the Current Shunt 10 A c Connect Meter Calibrator LO to the Current Shunt Common Install the Current Shunt shorting plugs in the 10 A holes Using AVM 2000 RANGE knob select the first AVM 2000 range listed in the Range column of Table 5 2 Perform Manual Range Zero of the AVM 2000 except set the Meter Calibra
29. cked by depressing the control once The control s locked unlocked status is shown in an adjacent area of the LCD A amp closed padlock indicates locked status OVER VOLTAGE If a potentially harmful over voltage exists at the instrument s input amplifier the Over Voltage circuit is activated Once activated the instrument is disconnected from the input terminals and an over voltage status is shown on the LCD NOTE The Over Voltage only operates when the instrument Range is 1 mV or below unless an extreme over voltage occurs 1 300 V on the 3 mV and above ranges such voltages are likely to damage the instrument When an over voltage condition occurs the first step is to remove the source of input over voltage After the over voltage source is cleared depressing the OPERATE ZERO pushbutton once returns the instrument to operation in the ZERO mode Depressing the OPERATE ZERO pushbutton once again returns the instrument to the OPERATE mode 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 4 TEGAM Section IV Operating Instructions WARNING FAILURE TO REMOVE THE SOURCE OF INPUT OVER VOLTAGE BEFORE RESTORING NORMAL INSTRUMENT OPERATION MAY CAUSE SERIOUS DAMAGE TO THE INSTRUMENT NOTE Although the over voltage circuits protect the instrument from substantial excessive voltages at its inputs it cannot protect the instrument against damage from extremely high voltage spikes that can occur when
30. d on a taut band zero center 41 inch mirror backed dual scale analog meter A rotary control provides selection of the instrument s 21 ranges Instrument status range offset voltage filter settings battery condition input impedance selection etc are displayed on a front panel LCD The AVM 2000 may be operated from the AC power line an internal rechargeable battery or an external DC source of 12 30 V The instrument s internal battery charger operates any time the AVM 2000 is connected to a power source and the instrument is in a standby mode Voltages to be measured are applied to the AVM 2000 via low thermal EMF front panel input terminals HI and LO A GUARD terminal is provided to connect input wiring shields A FILTER selection feature allows the operator to choose signal filtering from 0 1 to 100 seconds to improve measurements An OFFSET feature allows the user to offset a wide range of input voltages An OPERATE ZERO switch allows the user to disconnect the HI input terminal from the amplifier input and short the amplifier input to input common LO The user may select any one of 4 different input impedances for ranges below 3 mV and either 10 or 100 MQ for ranges of 3 mV to 300 V The 1 kV range input impedance is fixed at 100 MQ A multi mode INPUT OFFSET control allows the user to adjust the instrument s zero voltage for the current range to inject an input offset current of up to 2 5 nA to offset the effects of i
31. dd to meter response time 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 2 TEGAM Section I Introduction Instrument Noise 400 pV peak to peak shorted input3 RTI Equivalent noise source approximately 30 ohms Outputs Isolated yielding 0 5 to 1 5V user adjustable for full scale deflection Isolation Input to case or output gt 100 GQ typically gt 500 GQ Overload Protection 1100 VDC or peak on any range Meter 4 2 Mirror Backed with 3 0 3 and 10 0 10 Scales Status Backlit LCD Range Offset Filter Response Time Input Impedance ZERO OPERATE Mode Input Offset Mode and Isolated Output Mode 22 5 Ibs e Low thermal EMF input terminals plus guard e Two output Binding Posts plus a third for case common e Input terminal cover Power Supply e Internal rechargeable battery e External 12 to 30 V DC 01 25 Ampere e External Power Cube included Environmental Operating Temperature Range 15 30 C Full Specifications Operating Humidity Range 0 50 RH Full Specifications Storage Temp Humidity 20 to 60 C 0 80 non condensing a Inputs shorted by a low EMF strap firmly connected between HI and LO input connections Lesser performance may be experienced when shorted input is accomplished by ZERO switch Constant temperature 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 3 TEGAM Line Voltage Selection
32. e zero operate or input impedance change occurs or if the control s position is reset to the center or neutral position The user can reset the control to the center neutral i e no offset position by depressing and holding the control depressed for 5 seconds 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 3 TEGAM Section IV Operating Instructions When I is displayed the control allows the user to inject currents of 2 5 nA into the input amplifier and its driving source This adjustment allows the user to offset any natural instrument and or measurement bias currents flowing through driving impedances causing an offset voltage Turning the control clockwise injects a positive current and counterclockwise injects a negative current Holding the control depressed for 5 seconds or longer resets the offset current to O NOTE The level of injected offset current does NOT change as ranges are changed thus the input offset current need only be set once however the offset current returns to zero when the instrument power is turned off NOTE When nulling input bias currents the user may find using a 100kQ low noise resistor or a low noise resistor value approximating the source impedance of the device connected between the HI and LO input terminals is beneficial When using a 100 kQ resistor the 30 uV range is a good choice as a starting point The 30 uV range and a 100 kQ resistance shows input b
33. e balance of the instrument to ensure minimum noise introduction into the measurement signals from control digital signals and to ensure that when operating as a floating null meter the impedance to chassis earth ground from either of the two input terminals is extremely high The heart of the AVM 2000 is in the Isolated Analog Subsystem This is where nano volt level signals are amplified via low drift low noise amplifiers to a level where they can drive a wide dynamic range 24 bit analog to digital converter and where initial analog filtering 10 Hz 4 pole Butterworth low pass is applied Once the signal is in digital format it is further filtered scaled and transferred across the isolating boundary for meter display and rear panel output as a high speed serial signal An ISOLATED OUTPUT is available so the AVM 2000 may be operated as a high gain instrumentation amplifier with isolated output When used as an instrumentation amplifier the amplifier s gain is the inverse of the AVM 2000 s range control setting For example at the 1 uV range and with the ISOLATED OUTPUT set to 1 V for full scale response the amplifier gain is 1 V 1 uV 1 000 000 Input signals are applied to the AVM 2000 s low thermal EMF binding posts From here the signals are routed directly to the programmable input attenuator Depending on the selected measurement range the input signal is applied directly to the input amplifier 100 nV 1 mV ranges via a matched set o
34. e input voltage and the indicated OFFSET voltage NOTE This is NOT the button used to zero the meter INPUT MO Pushbutton The INPUT MQ momentary action pushbutton allows the user to select the value of resistance present between the HI and LO input terminals By successively depressing the momentary INPUT M amp pushbutton increments through 1 MQ 10 MQ 100 MQ and 1 GQ for ranges 100nV through 1mV 10MQ 100MQ from 3mV through 300V ranges 100MQ 1 000 V range NOTE This button is not active when OPERATE ZERO button is set to ZERO INPUT OFFSET Rotary Control Pushbutton This is a multi function button and should be thoroughly understood prior to operating any other controls on the AVM 2000 The INPUT OFFSET rotary control is a rotary encoder that when enabled by momentarily depressing the control allows the user to perform a number of zeroing functions When the instrument is first initialized the control is locked This is shown by a amp a padlock icon adjacent to the control in the LCD Depressing the control once changes the padlock icon to V and depressing the control again changes the icon to I When V is displayed the control allows the user to fine tune the current range and mode zero position Turning the control clockwise moves the meter upscale and turning the control counterclockwise moves the meter downscale The control has a range of approximately full scale The zero adjustment setting is stored at anytime a rang
35. e the Front Panel Subsystem If not above rotate the AVM 2000 RANGE control to the 100 mV range and apply a 100 mV DC input Signal to the AVM 2000 Using an oscilloscope or pulse detecting logic probe check for serial communications from the Isolated Analog Subsystem to the Front Panel Subsystem 19 200 baud 10 character bursts should be present at connector J2 Pin 6 If bursts are present the Front Panel Subsystem is not properly detecting and interpreting them Action Replace the Front Panel Subsystem If no bursts are present look for similar bursts from the Front Panel Subsystem to the Isolated Analog Subsystem at connecter J2 Pin 5 of the Front Panel Subsystem If no bursts are present the Front Panel Subsystem is not properly generating them Action Replace the Front Panel Subsystem If bursts are present the Isolated Analog Subsystem is not properly detecting and interpreting them Action Replace the Isolated Analog Subsystem Symptom AVM 2000 does not operate properly in some RANGE control positions but operates correctly on other ranges or the OFFSET function FILTER function Z IN function or ZERO function fails to operate a defective Isolated Analog Subsystem is indicated Action Replace the Isolated Analog Subsystem 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 17 Section V Maintenance and Servicing Symptom No output on AVM 2000 Meter but signal at ISOLATED OUTPU
36. eyond these limits can affect the accuracy of the instruments and damage internal circuitry CAUTION When the AVM 2000 is to be stored for extended periods pack the instrument into a container Place container in a clean dry temperature controlled location If instrument is to be stored in excess of 90 days place desiccant with items before sealing container The safe environmental limits for storage are 20 to 60 C and 0 to 80 non condensing relative humidity Do Not Use in Explosive Environments CAUTION The AVM 2000 is not designed for operation in explosive environments Ensure Power Switch is Accessible CAUTION Ensure that the POWER switch is easily accessible at all times and nothing is in place that would impede proper use Do Not Operate Without Covers WARNING This device should be operated with all panels and covers in place Operation with missing panels or covers could result in personal injury 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 2 1 TEGAM Section III Principles of Operation Understanding the AVM 2000 Measurement Process Basic operation of the AVM 2000 and an understanding of how it achieves its specified levels of performance follow The AVM 2000 architecture consists of three main sections an Isolated Analog Subsystem a Front Panel Subsystem and a Power Supply Subsystem The Isolated Analog Subsystem is optically and therefore electrically isolated from th
37. f low thermal EMF polarity reversal relays or is attenuated to be compliant with the input amplifier s dynamic range and then applied to the input amplifier 3mV 1000V On all ranges all stages of the input amplifier allow sufficient head room so peak noise does not cause limiting and very high loop gains ensure low distortion This allows the AVM 2000 to make full use of the digital filtering technology to eliminate unwanted noise from the measured signals Before signals are applied to the input amplifier they pass through input protection circuitry This protects the input amplifier from the direct application of excess voltage up to 1 100 VDC peak on any input range Additionally the AVM 2000 input attenuator can be configured in the 100 nV to 1 mV full scale ranges as a 1 MO 10 MO 100 MQ or 1 GQ input termination resistance user selectable Input impedances for ranges between 3 mV full scale and 300 V full scale are 10 MQ or 100 MQ The 1 kV range input impedance is fixed at 100 MQ Signals that are to be applied directly to the amplifier pass through a matched set of polarity reversing relays When measuring signals on ranges of 1 mV or less one half of all measurements are made with the relays in the NORMAL configuration and one half of all measurements are made with the relays in the ALTERNATE polarity reversal configuration When the respective signals are digitized they are subtracted from each other thus minimizing the impact
38. from the power supply board to the front panel board J1 7 Remove the two screws that fasten the base plate to the front panel 8 Tip the front panel forward sufficiently to expose the rear of the three front panel binding posts unsolder the HI and LO input terminal connections NOTE These connections are made with high quality silver solder to minimize input thermal EMF and disconnect the Isolated Analog Subsystem from the GUARD binding post 9 To remove the Isolated Analog Subsystem as a unit place the instrument on its side and remove the 8 nylon bolts that connect the Isolated Analog Subsystem to the instrument base plate CAUTION The Isolated Analog Subsystem in its metal box is very heavy Assistance in the disassembly process helps reduce the potential of damage from dropping components during the disassembly assembly process 10 Remove the metal box containing the analog subsystem together with its connection cables and insulating plate from the case 11 If access to the internal Isolated Analog Subsystem board is required remove the top cover retaining screws and top cover Next remove the captivating screws and lock washers from the 4 mounting studs to free the Isolated Analog Subsystem board If the board is being replaced the inter connect cables must also be removed for reinstallation on the replacement board 12 Installation of the isolated analog subsystem and or the analog subsystem board is performed by reversing the o
39. he displayed LCD value of offset voltage The offset voltage can be varied from 30 000 00 uV to 30 000 00 uV in 0 01 UV steps Each digit within the offset voltage display is adjusted up or down independently The digit to be adjusted is indicated by an underscore e g 03 000 00 or 00 300 00 The position of the underscore is selected using the INPUT OFFSET control while the padlock icon is displayed to the left of the control Depressing and holding one of the OFFSET pushbuttons allows continuous movement of the selected OFFSET voltage digit NOTE Incrementing or decrementing a position within the displayed OFFSET voltage causes a carry to higher order or lower order digit as appropriate Depressing both OFFSET pushbuttons simultaneously resets the offset to 00 000 00 uV NOTE Each range has a maximum permissible offset Exceeding this offset produces no further offset and the uV icon blinks OPERATE ZERO Pushbutton A momentary action pushbutton switch selects the OPERATE measurement or ZERO mode In the ZERO mode the connection between the HI input terminal and the internal amplifiers is opened the amplifier input is shorted to the amplifier common and any OFFSET voltage is removed When the ZERO mode is selected the instrument input impedance setting as displayed on the LCD is replaced with ZERO In the OPERATE mode the voltage to be measured is applied to the input amplifier and the displayed output voltage is the sum of th
40. ial the Range Rotary Control Pushbutton changing the range to 3 uV and repeat step 7 and repeat on every range up to and including 10 V ae Procedure for Zeroing the AVM 2000 in OPERATE mode 1 Power On the AVM 2000 and allow for normal instrument warm up 2 Set the Filter to 2 0 sec a Press the Filter push button s until the display shows 2 0 sec b Other Filter ranges may be used but 2 0 sec is the optimal for zeroing 3 Select what Ranges need zeroing 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 6 TEGAM Section IV Operating Instructions NOTE Knowing what ranges to zero can reduce your procedure time exponentially For example to achieve sub part per million results while calibrating a 10 V source the operator would calibrate fro 10 V to 1 uV There would really be no need to calibrate the ranges above 10 V or below 1 pV 4 Place the AVM 2000 in OPERATE mode a Press the OPERATE ZERO button until the 10 MQ appears in the display NOTE 10 MQ is selected because that is the impedance of the Fluke 845 and familiar to most users and calibration procedures The user can select the desired impedances at this point Tt is important to note that a separate zero needs to be performed for each impedance as well as range It is not typical to changes impedances during a calibration Dial the Range Rotary Control Pushbutton to the range on the display changes to 1 yV Press the INPUT O
41. ias currents of 300 pA full scale and allows nulling these input bias currents to substantially less than 1 pA If the initial indication is off scale change the range to 100 uV and then downrange to 30 uV Alternatively the 1 MQ input impedance selection may be used Once the range is zeroed or a desired level of input offset current is selected the INPUT OFFSET control may be locked by depressing the control until the padlock icon is displayed This prevents further adjustment of the range zero function or input offset current The control s locked unlocked status is shown in an adjacent area of the status LCD A8 closed padlock indicates locked status Either V or I indicate unlocked status NOTE with the padlock displayed adjusting the INPUT OFFSET control allows the user to select which digit of the OFFSET voltage responds to the OFFSET up and down pushbuttons An underscore is displayed under the selected digit e g 03 000 00 or 00 300 00 OUTPUT LEVEL Rotary Control Pushbutton This is a multi function button and should be thoroughly The OUTPUT LEVEL rotary control is a rotary encoder that allows the user to adjust the ISOLATED OUTPUT level The range of this control allows the user to adjust the ISOLATED OUTPUT voltage from 0 5 volt to 1 5 volt when the meter is deflected to full scale The OUTPUT LEVEL control also serves to set the ISOLATED OUTPUT zero voltage when in Setup mode The OUTPUT LEVEL control is unlocked or lo
42. longer than 6 months Another solution is to charge the battery periodically within 6 months during the storage period 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 8 1
43. mV 100 mV 300 mV 1 V 3 V 10 V 30 V 100 V 300 V 1 kV 1000 V The selected range full scale value displays on the LCD Push For Menu This control performs secondary functions such as instrument setup routines To access to these functions depress the RANGE control for approximately 5 seconds after which the set up menu appears in the LCD Rotating the RANGE control in this mode causes the LCD to display various setup options FILTER Pushbuttons Two momentary action FILTER pushbuttons allow the user to increase or decrease the filter setting Filter integration time is shown on the LCD The available filters 0 1 0 2 0 5 1 2 5 10 20 50 and 100 seconds An input signal is averaged running average before driving the meter movement or isolated output over these times NOTE Input ranges of 10 uV and below have a restricted range of filter times see Table 4 1 Rage Filter pot Table 4 1 Table of Ranges Input Impedance and Available Filter Settings 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 2 TEGAM Section IV Operating Instructions OFFSET Pushbuttons Two momentary action OFFSET pushbuttons allow the user to increase or decrease an internal offset voltage that is applied when the instrument is in the OPERATE mode The indication displayed on the meter or output at the rear panel is the sum of the input voltage and t
44. nput bias currents on high impedance voltage sources or to select the digit of offset voltage to be changed A two terminal rear panel output is provided for use with external devices such as chart recorders remote data acquisition systems digital readouts etc This output allows the AVM 2000 to function as a high sensitivity instrumentation amplifier with gains that are the inverse of the input attenuator settings These two terminals are an ISOLATED OUTPUT A third rear panel terminal is connected to the case A front panel control allows adjustment of the full scale output level from 0 5 volts to 1 5 volts Capabilities The AVM 2000 is designed for the calibration laboratory By utilizing a unipolar high gain low drift amplifier coupled with the ability to attenuate or amplify the input voltage makes the AVM 2000 ideal for nulling applications calibrations This is ideal for comparing an unknown to a known comparing a 10 V source to a voltage standard 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 1 TEGAM Specifications Includes performance characteristics description power and utility information and environmental information Table 1 1 Physical and Electrical Specifications Inputs and Ranges e One set of input terminations for all ranges e HI LO amp Guard e Low end 100nV full scale deflection with 2nV resolution e High end range 1000V full scale deflection with 5V or better resol
45. packaging and shipping the product to the designated TEGAM service center with shipping charges prepaid TEGAM Inc shall pay for the return of the product to the customer if the shipment is to a location within the country in which the TEGAM service center is located The customer shall be responsible for paying all shipping duties taxes and additional costs if the product is transported to any other locations Repaired products are warranted for the remaining balance of the original warranty or 90 days whichever period is longer Warranty Limitations The TEGAM Inc warranty does not apply to defects resulting from unauthorized modification or misuse of the product or any part This warranty does not apply to fuses batteries or damage to the instrument caused by battery leakage Statement of Calibration This instrument has been inspected and tested in accordance with specifications published by TEGAM Inc The accuracy and calibration of this instrument are traceable to the National Institute of Standards and Technology through equipment which is calibrated at planned intervals by comparison to certified standards maintained in the laboratories of TEGAM Inc Document publishing dates may lag product changes Visit www tegam com to download the latest version of this manual Contact Information TEGAM INC 10 TEGAM WAY GENEVA OHIO 44041 PH 440 466 6100 FX 440 466 6110 EMAIL sales tegam com WEB http www tegam com TEGAM
46. pushbuttons Wait at least 10 seconds Simultaneously depress and then release both OFFSET pushbuttons 10 The LCD momentarily displays OFFSET TRIM and then returns to displaying METER OFFSET 11 Depress the RANGE control to return the instrument to the normal operating mode N m 0 COND Uu W If a Total Instrument Reset is successfully performed the instrument when in ZERO mode with no OFFSET should display meter indications of O 1 3 of full scale for all ranges greater than 3 uV Once a successful Total Instrument Reset is performed the instrument requires re zeroing of each range in both ZERO and OPERATE modes Gain calibration may or may not be required Memory Sanitization Procedure Since there is no external access to the any of the AVM 2000 memory there is no memory system to sanitize on the AVM 2000 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 6 1 TEGAM Section VII Preparation for Shipment Returning AVM 2000 for Service Use the information in this section if you need to return your AVM 2000 to TEGAM Package AVM 2000 for Shipment Use the following steps to package the AVM 2000 for shipment to TEGAM for service 1 4 5 Fill the EXPEDITE REPAIR amp CALIBRATION FORM found in Section I and attach it to the AVM 2000 Please be as specific as possible about the nature of the problem Send a copy of any or all of the following information o Any error messages tha
47. rder of the above removal steps Be sure to use silver solder to re connect the Isolated Analog Subsystem input cable to the input binding posts 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 2 TEGAM Section V Maintenance and Servicing NOTE Failure to keep components and or the printed circuit board in the Isolated Analog Section clean of contaminants may compromise the performance of the AVM 2000 Avoid touching the electrical surfaces of the printed circuits unless wearing clean gloves 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 3 Section V Maintenance and Servicing Calibration Verification Preliminary Calibration Operations 1 Connect test equipment to appropriate power sources set POWER switches to ON and allow a warm up period Suggest 4 hours NOTE Recommend use of low thermal EMF shielded test leads solid copper wire or solid copper wire with gold plated spade terminals NOTE Before continuing ensure AVM 2000 has been connected to external power for a minimum of 20 hours 2 With AVM 2000 POWER switch set to OFF disconnect AVM 2000 from external power source and mechanically zero AVM 2000 meter NOTE The AVM 2000 must remain at the same tilt level during warm up and throughout the Calibration Process 3 Set AVM 2000 POWER switch to On ensure AVM 2000 indicates a fully charged battery and allow a one hour warm up period
48. rn TI RANGE knob clockwise until AVM 2000 LCD indicates ZERO RANGE or ZERO ALL If AVM 2000 LCD indicates ZERO RANGE simultaneously press OFFSET V A buttons so that AVM 2000LCD readout indicates ZERO ALL otherwise proceed to next step CAUTION Do not turn AVM 2000 RANGE switch clockwise again with the short attached AVM 2000 could be damaged if a reference voltage is selected with a short attached 27 28 29 Press AVM 2000 OUTPUT LEVEL knob AVM 2000 LCD will indicate a blinking ZERO ALL When the ZERO ALL indication stops blinking the zeroing process is complete approximately 5 minutes Press AVM 2000 RANGE knob 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 5 TEGAM Section V Maintenance and Servicing 30 Disconnect the Digital Multimeter and remove the short connected to AVM 2000 HI and LO terminals 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 6 Section V Maintenance and Servicing Calibration Process Required Equipment METER CALIBRATOR Range O to 1020 VDC O to 0 306 ADC Accuracy VDC 0 239 of output ADC 0 072 of output Suggestion Fluke 5700A CURRENT SHUNT Range 0 01 Q Accuracy 0 072 of value Suggestion Guildline 9211A DIGITAL MULTIMETER Range O to 1 5 VDC Agilent Accuracy 0 072 of rdg Suggestion Agilent 3458A Analog Meter Calibration 1 Connect the Meter Calibrator OUTPUT HI
49. s not show the normal fully charged reading Disconnect the battery and measure its open circuit voltage If the open circuit battery voltage lies between 5 3 and 7 0 volts the Front Panel Subsystem battery monitoring circuit is defective Action Replace the Front Panel Subsystem If the open circuit battery voltage is substantially below 5 3 volts the battery has one or more shorted cells Action Replace the battery 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 16 Section V Maintenance and Servicing Symptom No AVM 2000 Meter readings and no signal at the ISOLATED OUTPUT on all ranges Action Ensure the AVM 2000 front panel OPERATE ZERO Switch is in the OPERATE position If not above check that the power supply voltage being delivered to the Isolated Analog Subsystem as measured between pins 1 2 and 4 at connector J1 is 5 VDC 0 25 volts If 5 volts is not being delivered to the Isolated Analog Subsystem check the voltage into the Front Panel Subsystem at connector J1 pin 3 to 9 and pin 4 to 10 This should be between 5 3 and 7 0 volts If no voltage is present there is a Power Supply Subsystem Battery problem Action Use the steps above to isolate a Power Supply Subsystem Battery problem If the voltage is present at the input to the Front Panel Subsystem but not being delivered to the Isolated Analog Subsystem the Front Panel Subsystem is defective Action Replac
50. stem If the fuse continues to blow the Front Panel Subsystem is defective Action Replace the Front Panel Subsystem If the fuse no longer blows the Isolated Analog Subsystem is defective Action Replace the Isolated Analog Subsystem 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 15 TEGAM Section V Maintenance and Servicing Symptom AVM 2000 operates with the AC Power Module connected but not properly on the internal rechargeable battery Internal rechargeable battery needs to be charged Action Charge battery as described There is a problem with the battery charging circuit Action Check the voltage across the battery terminals the voltage should be between 6 0 and 7 5 volts DC when the AC Power Module is connected i e when the battery is charging A lower voltage indicates a failed Power Supply Subsystem a failed rechargeable battery or a deeply discharged battery allow sufficient time to charge the battery Disconnect the battery and measure its open circuit voltage If the open circuit battery voltage lies between 5 3 and 7 0 volts the Power Supply Subsystem is defective Action Replace the Power Supply Subsystem If the open circuit battery voltage is substantially below 5 3 volts the battery has one or more shorted cells Action Replace the battery Symptom AVM 2000 internal rechargeable battery charges but the level displayed on the AVM 2000 LCD doe
51. t appeared on the power meter display o Any information on the performance of the AVM 2000 Use the original packaging materials or a strong shipping container The carton must be both large enough and strong enough to accommodate the power meter and allow at least three to four inches on all sides of the power meter for packing material Surround the power meter with at least three to four inches of packing material or enough to prevent the power meter from moving in the carton Seal the shipping container securely with strong nylon adhesive tape Mark the shipping container FRAGILE HANDLE WITH CARE to ensure careful handling CAUTION AVM 2000 damage can result from using packaging materials other than those specified 6 Retain copies of all shipping papers NOTE Refer to page 1 6 of the introduction for information on how to obtain a RMA from TEGAM 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 7 1 TEGAM Storage When the AVM 2000 is to be stored for extended periods pack the instrument into a container Place container in a clean dry temperature controlled location If instrument is to be stored in excess of 90 days place desiccant with items before sealing container The safe environmental limits for storing the AVM 2000 are 20 to 60 C 0 80 non condensing CAUTION AVM 2000 has a rechargeable battery It is essential to either remove the battery if storing periods
52. t the Meter Calibrator for 100 mA DC Adjust AVM 2000 OUTPUT LEVEL knob until the Digital Multimeter indicates 1 500 0 003 VDC Press the Meter Calibrator SCALE button Set the Meter Calibrator for 80 mA DC and edit the output amplitude until the Digital Multimeter indicates 1 200 0 003 VDC The LinError indicated on the Meter Calibrator display must be within 0 5000 to 0 5000 Repeat steps 10 and 11 with 60 mA DC and 0 9 VDC 40 mA DC and 0 6 VDC 20 mA DC and 0 3 VDC Press the Meter Calibrator SCALE button setting the function off Repeat steps 7 through 12 with negative applied current and Digital Multimeter indications Set the Meter Calibrator OPR STBY switch to STBY and press the SCALE and OFFSET buttons setting the functions off 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 10 TEGAM Section V Maintenance and Servicing 16 Disconnect test setup 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 11 Section V Maintenance and Servicing Offset Voltage Calibration i 10 Lh 12 13 14 I5 16 17 Connect the Meter Calibrator OUTPUT HI and LO terminals to AVM 2000 front panel HI and LO terminals respectively Perform Manual Range Zero on AVM 2000 1 mV and 3 mV ranges Using AVM 2000 RANGE knob select the 30 mV range Set the Meter Calibrator for 27 mV DC and set OPR STBY switch to OPR Using AVM 2
53. the over voltage condition is transient in nature and the voltage spikes are very high due to inductive spiking For this reason great care should be taken when using the instrument in high sensitivity modes especially on ranges of 1 mV and lower with very high measurement differential voltages Normal Operation Normal calibration laboratory practice dictates that the environment should be closely controlled This will minimize errors introduced by temperature and humidity changes A nominal temperature of 20 C provides a good working condition A tolerance of 5 C gives allowable temperature spread Controlled temperatures also stabilize the aging process of the standards 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 4 5 TEGAM Section IV Operating Instructions Setting Zero Procedure Purpose The AVM 2000 zeroing procedure is significantly different from older Null Meters such as the Fluke 845 It is important to remember that when adjusting for zero in the ZERO mode the adjustments do not affect the OPERATE mode measurements The benefit of zeroing in the ZERO mode allows the user to observer any possible drift in the instrument amplifiers since the last zero This observation helps determines any possible drift errors affect the current test procedure Equipment e TEGAM AVM 2000 Null Meter Connections 1 Plug in all test and measurement equipment 2 Connect shorting strap between the
54. this 24 bit result based on front panel FILTER settings The processor then converts the 24 bit word into a bit stream that is optically coupled to the Front Panel Subsystem The 24 bit conversion gives a resolution in excess of one part in 16 million to provide a high degree of overall linearity and resolution ultimately after processing 18 bits 17 bits of amplitude resolution and one sign bit The 24 bit conversion allows extensive digital filtering and manipulation to assist in the measurement and noise reduction process Once the digitized and optically isolated measurement information is received by the Front Panel Subsystem the output is converted from serial information and is sent to a 20 bit digital to analog converters with updates every 200 mS The digital to analog converter output is buffered and sent to the 4 12 inch zero center mirror backed meter movement This meter provides a high resolution readout with both 10 O 10 and 3 O0 3 scales A second 20 bit digital to analog converter output is sent to a buffer amplifier This output is normalized to 1 V at full scale corrected for any gain normalizations set by the operator who can make gain adjustments which set the ISOLATED OUTPUT full scale level at 0 5 V 1 5 V for a full scale input and is applied to the ISOLATED OUTPUT rear panel terminals This output allows the operator to utilize the AVM 2000 as a high gain high linearity chopper stabilized for ranges of 1m
55. tor for 0 ADC in step 4 a i Set the Meter Calibrator for the first positive value listed in the Applied column of Table 5 2 and set the OPR STBY switch to OPR Edit the Meter Calibrator output amplitude until AVM 2000 analog meter indicates full scale The Meter Calibrator must indicate within the corresponding positive values listed in the Limits column of Table 5 2 Set the Meter Calibrator OPR STBY switch to STBY Repeat steps 40 through 43 for the first negative value listed in the Applied and Limits column of Table 5 2 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 5 9 TEGAM Section V Maintenance and Servicing 45 Repeat steps 38 through 44 for each remaining value listed in the Range and Applied columns of Table 5 2 am 203 20 2940 to 0 3080 Set TI IMPEDANCE to 1 MQ using the INPUT MQ BURON Table 5 2 Isolated Output Calibration 1 10 11 12 13 14 15 Connect the Digital Multimeter INPUT HI and LO terminals to AVM 2000 rear panel and terminals respectively Set the Digital Multimeter FUNCTION for DCV and AUTO range Using AVM 2000 RANGE knob select the 1 mV range Perform Manual Range Zero of the AVM 2000 except set the Meter Calibrator for 0 mA DC and leave the Meter Calibrator in OPR Edit the Meter Calibrator output amplitude until the Digital Multimeter indicates 0 000 0 003 VDC Press the Meter Calibrator OFFSET button Se
56. ution e 21 selectable ranges 1 3 10 sequence Outputs and Indicators 2 output indications e Analog meter e Isolated analog rear panel output Analog Output Accuracy 0 5 of full scale of range selected typically 0 1 e Resolution Within 0 1 of full scale of selected range after floor noise compensation e Linearity Within 0 5 of full scale of selected range Analog Meter Accuracy 2 of full scale of selected range e Scaling Mirrored zero center 10 0 10 and 3 0 3 e Linearity lt 1 of full scale of selected range e Resolution lt 1 of full scale of selected range typically 0 5 of full scale of selected range Meter Response Time To 90 of final reading 100 nV 1 uV full scale 5 seconds 3 pV full scale 3 seconds All other ranges 1 5 seconds Input Impedance 100 nV to 1 mV FS 1 MO 10 MO 100 MQ or 1 GQ Selectable 10 3 mV to 300 V FS 10 MQ or 100 MQ 5 1 KV FS 100 MQ 5 Offset Current Adjustable 2 5 nA to zero at front panel 10 position digital low pass filter selectable from front panel 100 200 500 mSec 1 2 5 10 20 50 100 Sec Offset Continuously variable 0 to 999 9 of range offset for all ranges e Resolution lt 01 of offset full scale e Accuracy lt 0 5 of offset full scale Series Mode Rejection gt 80dB at 50Hz 60 Hz l Meter specification measurements and terms per ANSI C39 1 2 With filter response time set to 100 ms Otherwise filter response times a
57. will expedite the processing and repair process RMAS 1 1 1 instrument Model Number Technical Contact Phome Number Z o o Additional Contact Info Repair Instructions Evaluation Calibration Only Repair Only Repair amp Calibration Z540 Extra Charge Detailed Symptoms Include information such as measurement range instrument settings type of components being tested is the problem intermittent When is the problem most frequent Has anything changed with the application since the last time the instrument was used etc 10 TEGAM WAY GENEVA OHIO 44041 440 466 6100 FAX 440 466 6110 www tegam com 1 7 TEGAM Warranty TEGAM Inc warrants this product to be free from defects in material and workmanship for a period of one year from the date of shipment During this warranty period if a product proves to be defective TEGAM Inc at its option will either repair the defective product without charge for parts and labor or exchange any product that proves to be defective TEGAM Inc warrants the calibration of this product for a period of 1 year from date of shipment During this period TEGAM Inc will recalibrate any product which does not conform to the published accuracy specifications In order to exercise this warranty TEGAM Inc must be notified of the defective product before the expiration of the warranty period The customer shall be responsible for

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