Keithley 197A User Manual Download Page 38 | Manualshive

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Keithley 197A User Manual Download Page 38

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Summary of Contents for 197A

Page 1: ...Model 197A AutorangingMicrovolt DMM User s Manual MY MY A GREATER MEASURE OF CONFIDENCE A GREATER MEASURE OF CONFIDENCE...

Page 2: ...Model 197AAutoranging Microvolt DMM User s Manual 01990 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A Third Printing February 2001 Document Number 197A 901 01 Rev C...

Page 3: ...ossible wear cracks or breaks before eachuse If any defects arefound replace the test leads For optimum safety do not touch the test leads or the instrument while power is applied to the circuit under...

Page 4: ...a I O connections zwefor connection to Category 1 sources un less otherwise marked or described in the Manual Exercise extreme caution when a shock hazard is present Lethal voltage may be present on c...

Page 5: ...ully before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the warranty lnslrumentation and accessories...

Page 6: ...197A5 D Mukimeter Specifications DCVOLTS 4CC RMx r g CO rm DCAMPS...

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Page 8: ...y 2 2 2 4 2 FrontPanelControls 2 4 2 4 3 InputTerminals 2 4 2 4 4 Current FuseReplacement 2 4 2 4 5 RearPanelSwitches 2 5 2 5 ERRORMESSAGES 2 5 2 6 OPERATINGCONDITlONS 2 5 2 6 1 Environmental Conditio...

Page 9: ...Accuracy Check 3 4 3 5 4 DC Current Accuracy Check 3 6 3 5 5 AC Current Accuracy Check 3 7 SECTION 4 Maintenance 4 1 INTRODUCTION 4 1 4 2 DISASSEMBLY INSTRUCTIONS 4 l 4 3 BATTERY PACK Model 1978 INSTA...

Page 10: ...cation Connections for ACV Verification Connections for 200R 2kQ and 2Okn Range Verification 4 terminal Connections for 2OOkQ through Ma Ranges Verification 2 terminal Connections for DC Current Verif...

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Page 12: ...n of Average and TRMS Meter Readings 2 19 SECTION 3 Performance Verification Table 3 l Equipment Specifications Table 3 2 Limits for DC Voltage Verification Table 3 3 Limits for AC Voltage Verificatio...

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Page 14: ...or eachinterface and respond to IEEE 488protocol 1 2 FEATURES The Model 197A includes the following features 1 Six Measurement Functions DCV ACV DCA ACA OHMS and dB all built in 2 EL Relative Mode The...

Page 15: ...ult in personal injury or death The CAUTION heading used in this manual explains haz ards that could damage the instrument 1 6 SPECIFICATIONS Detailed Model 197A specifications may be found preced ing...

Page 16: ...0A range Select dB by selecting AC or DC volts and press ing the dB button The dB annunciator will turn on and the default reference impedance 600R will be displayed momentarily Pressing dB a sec ond...

Page 17: ...anana plugs two phone tips 06 DIA two hooks and miniature alligator clips with boots MODEL 1972A ANALOG OUTPUT IEEE 488 INTER FACE The Model 1972A is an optional IEEE 488 interface that includes all o...

Page 18: ...an result even when the meter is set to a voltage range if the minimum voltage spacing is reduced When making measurements in high energy circuits use test leads that meet the following requirements l...

Page 19: ...nstrument to line power as described in paragraph 2 3 1 2 The battery charge circuit is energized automatically when the instrument is plugged into the AC line The of the power switch state When the b...

Page 20: ...ode AC AC selected DC implied by the absence of the AC annunciator AUTO Autorange REL Relative mV or V Millivolts or volts 0 kQ or MR Ohms kilohms or megohms dB Decibel measurement mode ST0 Data being...

Page 21: ...he volts function IL Depressing this button selects the ohms function The AC DC button must be released out A Depressing in this button selectsthe current func tion Up to 2A on red and black input jac...

Page 22: ...e instrument to the available line power voltage 2 5 ERROR MESSAGES Table 2 l lists the error messages associated with basic front panel operation Note that the instrument has a num ber of other messa...

Page 23: ...software revision level of the Model 197A can be displayed upon power up by running the diagnostic program WARNING Before operating the Model 197A observe all previously mentioned safety precautions...

Page 24: ...99999V Once the REL level is established that level is algebrai cally subtracted from the input signal For example if a l OOOOOVREL level is established then applying a Z OOOOOV level displays a l OOO...

Page 25: ...splay reading xk20mV z 22 V do004 484 x lo 2 0200000121 This offset is seenasthe last digit which is not displayed on the Model 197A Therefore the offset is negligible 5 Observe the display if the OL...

Page 26: ...e shielded and the shield connected to the Model 197A ground particularly for low level sources Improper shielding can causethe Model 197A to behave in one or more of the following ways 1 Unexpected o...

Page 27: ...ic range selection 4 If readings are to be made on the ZOO 2 range zero the instrument to obtain rated accuracy To zero the instrument for resistance measurements Short the test leads together after d...

Page 28: ...s asshown in Figure 2 8to help in nkimidng external fields which could affect the Model 197A or other equip ment Also keep the testleads asshort aspos sible to minimize voltage drop located on the fro...

Page 29: ...and DC components terminals of the Model 197A B Select the ACA or DCA function l C Selectan appropriate range for the expected cur Measure and record theTRMS AC component asde rent The current functi...

Page 30: ...ic procedure for placing the instrument in the dB mode is to first select AC or DC volts and then press the dB button The currently selected dB reference imped ancewill then be displayed briefly and t...

Page 31: ...made with other reference impedances The most convenient method for using other reference impedances is to algebraically subtract the calculated dB offset for the desired reference imped ance from th...

Page 32: ...will illustrate this uoint A B C Using the Model 1 97Ain the dB mode 6OOaref measure a 1mV RMS 1kHz source nmon ap plication in the communications field Typi cally the Model 197A will read 57 7dBm The...

Page 33: ...location number is briefly dis played For example Buffer location l is represented by n Ol c The Model 197A displays the applied signal and waits for the next manual rigger NOTE The logging cycle can...

Page 34: ...ommon types of waveforms For reference the first waveform is an ordi nary sine wave with peak amplitude of 1OV The average value of this voltage is 6 37V while its RMS value is 7 07V Ifweapplythe 1 11...

Page 35: ...SECTION 2 Bench Operation igure 2 10 Typical ACV Frequency Response 2 18...

Page 36: ...fied Square Wave Triangular Sawtooth o 0 V2 Coupled Peak Value 1ov 1ov 1ov 1ov 1ov 1ov 1ov RMS Value 7 07v 5 oov 7 07v lO OOV 5 oov 1ov J 5 77v Average iC Coupled Respondin TRMS Meter Meter Reading Re...

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Page 38: ...measurements should be made at an ambient tempera ture between WC and 28 C 65 F to 82 F with a relative humidity less than 80 3 3 RECOMMENDED TEST EQUIPMENT Equipment for verifying the performance of...

Page 39: ...O terminals or damage to the instru ment may occur WARNING The maximum common mode voltage volt age between input low and chassis ground is 500Vpeak Exceeding this value may cause a shock hazard Some...

Page 40: ...a frequency of 50Hz Verify that the reading is within the limits specified in Table 3 3 4 Repeat the 2 OOOOOV AC measurement at the other frequencies specified in Table 3 3 5 Check the 2OV 200V and 75...

Page 41: ...eethat the displayed reading is within the limits specified in Table 3 4 5 Connect a 1 9161calibration resistor to the instru ment asshown in Figure 3 3 Switch the instrument to the 2kQ range Verify t...

Page 42: ...SECTION 3 Performance Verification Figure 3 3 Connections for 20OQ 2kQand 2OkQ Range Verification 4 termimzl Figure 3 4 Connections for 20fJkQ through MQ Ranges Verijication terminal 3 5...

Page 43: ...A to the 2OmA range Set the calibrator to output 2O OOOOmA Verify that the dis played reading is within the limits specified in Table 35 6 Switch the Model 197A to the 2OOmArange Setthe calibrator to...

Page 44: ...Model 197A to the 2OmA range Set the calibrator to output 2O OOOOmA Verify that the dis played reading is within the limits specified in raGle 3 6 6 Change the Model 197A to the 200mA range Setthe ca...

Page 45: ...cation AC Voltage Calibrator Hi Input LOInput Model ZOOA Model 2500E igure 3 7 Connections forAC Current Verification 2OOpA to 200CJmA Model 343A Model 2500E Figure3 8 Connections for AC Current Verif...

Page 46: ...ication 197A AC Applied Range AC Current 2001 A 200 000 A 2mA 2 ooooomA 20mA 20 0000mA ZOOmA 200 000mA 2000mA 2000mA 10A 5 0000A 20Hz 50Hz 1OkHz 197 900 to 202 100 1 97900 to 2 02100 19 7900 to 20 210...

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Page 48: ...assem bly procedure Disassembly should be done in order that it is presented since in general each step depends on a previ ously performed procedure Most parts referred to in the following steps are s...

Page 49: ...ance LINEFUSE HOLDERBODY CURRENTFUSE SHELD FRONTPANELp s ATTERYPACK y EOnOM FUNCTION 29465 5 WHITE BJU 12 9 0 FUNCTION29465 7 A FUNCTION29465 6 RANGEI71294654 Figure 4 l Model 197AMiscellaneous Parts...

Page 50: ...Black Orange Grey white Mother Board Removal 1 Disconnect the AC power receptacle from the mother board at J P1007 2 Remove the four case spacers 3 Carefully lift the mother board out of the bottom ca...

Page 51: ...ure that they are properly con nected Otherwise damage to the instrument may result 8 Reinstall the top cover as explained in paragraph 4 2 NOTE The IEEE Interface options do not run off of bat tery p...

Page 52: ...njury C D E Guide the terminals of PlOOR and firmly push down on that end of the board to mate the connectors Push down on the other side of the interface board until it snaps onto the rear most stand...

Page 53: ...Plug in the line cord and tom on the instrument Press in the REL and dB push buttons simultaneously until the message CAL is dis played Release the buttons The unit is now in calibration as indicated...

Page 54: ...n mode Y annunciator on connect the AC voltage calibrator to the 1 Select the AC voltage function and the 200mV range 2 Set the calibrator to output 190 000mV at 500Hz 3 Adjust the display using the S...

Page 55: ...z Verify that the reading on the Model 197A is 00 0000 1200 counts Press REL REL annunciator turns off 2 Set the calibrator to output 5OO OOV at 2OkHz Adjust 103 for a reading 0f 000 00 50 counts PUSS...

Page 56: ...the ohms function 1 Select the 2OOn range and set the resistance calibrator to output zero ohms short 2 Press the REL button on the Model 197A The REL annunciator appears on the display and the displ...

Page 57: ...de the calibration switch to ENABLED Press If instead the message out is displayed then calibration REL and dB simultaneously until CAL appears on the storage was not enabled and the calibration const...

Page 58: ...ro 0 Will not read applied input 0 I articular range or function bad specify 0 Batteries and fuses are OK 0 Checked all cables cl Certificate of calibration required attach any additional sheets as ne...

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Page 61: ...ERLANDS SWITZERLAND TAIWAN Keithleyln mmenfs B Keith l SfNmenfS China KeitbleylnSt mentSSad Keitbky Instruments GmbH KehbleyInsrmmenfS Lfd KeithleyInstruments GmbH KeithleyInstruments s rI KeithleyIns...

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