Keithley 192 User manual

Model 192
Instruction Manual
Contains Operating and Servicing Information for
Model 192 Programmable DMM and Model 1910 AC Option
Publication Date: June 1984
Document Number: 30983 Rev. C

WARRANTY
Keithley instruments, Inc. warrants this product to be free from defects
in material and workmanship for a period of 1 year from date of ship-
ment. During the warranty period, we will, at our option, either repair
or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley represent-
ative, or contact Keithley headquarters in Cleveland, Ohio. You will be
given prompt assistance and return instructions. Send the instrument,
transportation prepaid, to the indicated service facility. Repairs will be
made and the instrument returned, transportation prepaid. Repaired
products are warranted for the balance of the original warranty period,
or at least 90 days.LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from unauthorized
modification or misuse of any product or part. This warranty also does
not apply to fuses, batteries, or damage from battery leakage.
This warranty is in lieu of all other warranties, expressed or implied, in-
cluding any implied warranty of merchantability or fitness for a par-
ticular use. Keithley Instruments, Inc. shall not be liable for any indirect,
special or consequential damages.
STATEMENT OF CALIBRATION
This instrument has been inspected and tested in accordance with
specifications published by Keithley Instruments, Inc.
The accuracy and calibration of this instrument are traceable to the
National Bureau of Standards through equipment which is calibrated at
planned intervals by comparison to certified standards maintained in
the Laboratories of Keithlev Instruments, Inc.
Keithley Instruments, Inc. I instruments Division
28775 Aurora Road i Cleveland, Ohio 44139 , “.‘%A
Phone: [phone] / Telex: 98.5469

Instruction Manual
Model 192
Programmable DMM
01982, Keithley Instruments, Inc.
Cleveland, Ohio, U.S.A.
Document Number: 30983

SPECIFICATIONS
DC VOLTS

TABLE OF CONTENTS
PARAGRAPH TITLE PAGE
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
2.1
2.2
2.2.1
2.2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
2.15
3.1
3.2
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
SECTION l-GENERAL INFORMATION
Introduction ...................................................................................
Features .......................................................................................
WarrantyInformation ...........................................................................
ManualAddenda ...............................................................................
SafetySymbolsandTerms .......................................................................
Unpackingandlnspection ........................................................................
Specifications. ................................................................................
Preparation for Use ............................................................................
Line Power ....................................................................................
Line Voltage Selection ..........................................................................
LineFrequencySelection ................................................................... .~,~
Repackingforshipment .........................................................................
SECTION Z-ACCESSORIES
Introduction ...................................................................................
RackMountingKits .............................................................................
Model1019ARackMountingKit ................................................................
Model1019SRackMountingKit ................................................................
Model1600AHighVoltageProbe .................................................................
Model1641KelvinTestLeadSet..............................................................~~
Model165150AmpereShunt................................................................~ ...
Model1681Clip-OnTestLeadSet.............................................................~
Model1682ARFProbe......................................................................~ ...
Model 1683 Universal Test Lead Kit. .......................................................... ..
Model 1685 Clamp-On AC Current Probe ........................................................
Model1901CurrentAdapter ......................................................................
Model1910ACVoltageOption...............................................................~ ..
Model1920TRMSACVoltOption ................................................................
Model19231EEE-488lnterface...............................................................~~~~
Modal1924RearlnputAdapter..............................................................~.~~
Model7008IEEE.488Cable.. ..................................................................
SECTION 3-FRONT AND REAR PANEL CONTROLS
Introduction ...................................................................................
Front Panel ....................................................................................
BenchModeofOperation ........................................................................
Bench Programming Mode of Operation. .........................................................
SystemModeofOperation .......................................................................
RearPanel .....................................................................................
SECTION 4-BASIC DMM OPERATION
Introduction ...................................................................................
Powerup....................................................................................~
Operating Instructions
...........................................................................
zero .........................................................................................
Overrangelndication ............................................................................
Filter .........................................................................................
DCVoltageMeasurement ........................................................................
ResistanceMeasurement ...................................................................... .,
Four-Wire Ohms Measurement ...................................................................
AC Voltage Measurement (1910AC Option). ........................................................
AC Voltage Measurement l192OTRMS Optionl, ....................................................
1-l
l-l
l-l
1-l
l-l
l-l
l-l
l-l
1-2
l-2
1.2
1-2
2-l
2-1
2-l
2-1
2-l
2-1
2-l
2-l
2-2
2-2
2-2
2-2
2~3
2-3
2-3
2-3
2-3
3-1
3-l
3-l
3-l
3-l
3-2
4-l
4-1
4-l
4-l
4-2
4-2
4-3
4-3
4-4
4-4
45

TABLE OF CONTENTS (CONT.1
PARAGRAPH TITLE PAGE
SECTION ‘&FRONT PANEL PROGRAMS
5.1 Introduction 5-1
5.2 ....................................................................................................................................................................Program Notes 5.,
5.3 P,og,a,“OC,~~, ................................................................................
5.4 Programl.Resolution ........................................................................... ;I;
5.5 ProgramZ.Filter .........................................................................................................................................................
5-4
5.6 Program3.Dffset/Scale 5-4
5.7 Program4. Percent Deviation.. ...................................................................
5.8 Program5,Min/Max ............................................................................ z:E
5.9 Program&HI/LO/PASS
;:;(: Program7.DataLogger .................................................................................................................................................
5-J
5-B
lEEEBufferOpmt,on ...........................................................................
5.12 ProgramB.ServiceProgram ...................................................................... ;I;
SECTION 6-PERFORMANCE VERIFICATION
6.1 Introduction ...................................................................................
6.2 Environmental Conditions ........................................................................ E:;
6.3 RecommendedTestEquipment
6.4 InitialConditions ................................................................................................................................................... E:i
6.5 Performanceverification ......................................................................... 6-l
6.5.1 DC Voltage Accuracy Check 12OV to 12OOV ranges) ............................................. 6-l
6.5.2 DC Voltage Accuracy Check (.2V to2V ranges1 ................................................. ..
6.5.3 AC Voltage Accuracy Check (With Model 1910 AC Voltage Option Installed) ........................... ;I:
6.5.4 Resistance(R)AccuracyCheck ................................................................. 6-2
SECTION 7-THEORY OF OPERATION
7.1 Introduction ................................................................................... 7-l
7.2 Overall Functional Description .................................................................... 7~1
7.3 Analog Circuit Description ....................................................................... 7-3
7.3.1 InputMultiplexer ............................................................................. 7-3
7.3.2
DCVoltage Measurement
7.3.3 ResistanceMeasurement ............................................................................................................................................ ;:;
7.3.4 ACVoltageMeasurement
7.3.5 InputBufferAmplifier ............................................................................................................................................... ;I:
7.3.6 AIDConverter ............................................................................... 7-7
7.4 Digital and Display Circuit Description ..............................................................
7.4.1 Microcomputer (Refer to Schematic 309750) ..................................................... ;:;
7.4.2 Memon/
7.4.3 ..............................................................................................................................................................
AddressDecoder.. ;:;;
7.4.4 Reset ......................................................................................
7.4.5 FrontPanelSwitchPort ....................................................................... ;:;;
7.4.6 LineFrequency .............................................................................. 7.11
7.5 AIDControl .................................................................................. 7.11
7.5.1 ClockCircuit
7.6 DisplayCircuit ................................................................................................................................................................. ;I;:
7.7 PowerSupply ................................................................................. 7.14
SECTION E-MAINTENANCE
6.1 Introduction ................................................................................... B-l
6.2 Calibration ..................................................................................... 8.1
6.2.1 RecommendedTestEquipment ................................................................. B-l
8.2.2 Environmental Conditions ...................................................................... B-1
ii

TABLE OF CONTENTS (CONT.)
PARAGRAPH TITLE PAGE
8.2.3 Warmup ................................................
8.2.4 Calibration Adjustments ...................................
8.3 Troubleshooting Set-Up Procedures
...........................
8.3.1 Line Power Fuse iFlO1) Replacement ........................
8.3.2 Line Voltage Selection .....................................
8.3.3 Disassembly .............................................
8.3.4 Special Handling of Static Sensitive Devices ..................
8.4 Troubleshooting Procedure ...................................
8.4.1 Line Power ..............................................
8.4.2 A/D Converter and Display .................................
8.4.3 ACConverter ............................................
8.4.4 DC Attenuator and Ohms Sources and Resistors. ..............
8.4.5 DigitalBoard .............................................
9.1
9.2
9.3
9.4
9.5
SECTION B-REPLACEABLE PARTS
lntrodution ................................................
Parts List ..................................................
Ordering Information ........................................
Factory Service .............................................
Schematic Diagrams and Component Location Drawings .........
.....................
......................
......................
......................
.... .... ..... ......
......
......
......
......
......
......
......
8-l
ai
8-2
8-2
8-4
8.4
8-5
8-5
8-6
8-6
86
86
86
9-1
9-1
9-1
9-l
9- 1
iii

LIST OF ILLUSTRATIONS
FIGURE TITLE PAGE
l-l
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2.11
2-12
2-13
2.14
3-l
3-2
4-1
4-2
4-3
4-4
4-5
4-6
5-1
6-l
7~1
7-2
7-3
J-4
7-5
7-6
J-7
J-8
7-9
7-10
7-11
7-12
7.13
7-14
7.15
7-16
7.Ii
J-18
7-19
7-20
8-l
9-1
9-2
9-3
9-4
9-5
l-2
2-1
2-l
2-1
2-1
2-2
2-2
2-2
2~2
Instrument Packaging ...........................................................................
Model1019RackMountingKit ....................................................................
Model1600AHighVoltageProbe .................................................................
Model 1641 Kelvin Test Lead Set ..................................................................
Model165150AmpereShunt ....................................................................
Model1681Clip-OnTestLeadSet .................................................................
Model1682ARFProbe..........................................................~......~ ........
Model 1683 Universal Test Lead Kit ................................................................
Clamp-OnACCurrentProbe ......................................................................
Model1901CurrentAdapter.............................................................~ ........
Model1910ACVoltageOption ....................................................................
Model 1920 TRMS AC Voltage Option .............................................................
Model 1923 IEEE-488 Interface ..................................................... ..... .....
IEEE-488Connector....................................................................~..~ .....
Model1924RearlnputAdapter .................................................................
Modell92FrontPanel.............................~.............................~.~ .............
Model192RearPanel ..........................................................................
Effect of Zero Function on Dynamic Range of Measurements ....................... ................
InputFilterFiesponseGraph ......................................................................
DCVoltageMeasurements .....................................................................
ResistanceMsasurements................~..........................~............~......~...~ ..
Four-Wire Resistance Measurement .............................................. ..
ACVoltage Measurements ........................................................... ~, ...
Front Panel Program Buttons ................. .................... ....... .. ..
TestCircuit,2mVand2V............~ .........................................................
Basic Block Diagram .................................................................... ,.,
Simplified Multiplexer Schematic. .................................. ........... .....
DCVoltage Measurement .................................................... ., ., .....
FET Switching Sequence for DC Voltage Measurement (Bench Mode of Operation) .. ...... .. ..
DC Voltage Measurement FET Switching Sequence (System Mode of Operation1 ..... .. .. .. .. ..
Resistance Measurement Simplified Circuit ....... ~, .................. ...... .... ...
FETSwitchingSequenceforOhmsMeasurement ................................
Affect of Lead Resistance in 2.Terminal Ohms Measurements. ................ ..
Affect of Lead Resistance in 4.Terminal Ohms Measurements. .......................... .... .. ....
Block Diagram AC Volts Operation ...... ..... ............... ... ..........
ACVoltsOperationFlowChart..~ .................................... ~,.,~ ...... ~.~.~,, .....
Simplified Input Buffer Schematic .............. .....................
Simplified A/D Converter Schematic ............. ...................... ... .. .... ..... ....
AID Converter Integrator Output Waveform ....... .................................... ... ..
Microcomputer Block Diagram ..................................................................
ChargeBalanceTimming .....................................................................
SingleSlopePhase.........~.........................................................~ ........
Simplified Schematic of Latch .............................................................. ....
Simplified Oscillator/Divider Diagram .................................. ..........................
Display Schematic ................................................................. ...........
Adjustment Locations .............................................. ................. ..........
Exploded View With Mechanical Parts .............................................................
AC Converter, Component Location Drawing ......................................................
MotherBoard,ComponentLocationDrawing ......................................................
Analog Board, Component Location Drawing ......................................................
Display Board, Component Location Drawing ......................................................
2-3
2-3
2~3
2-3
2~3
2-J
3~:~
3-2
4~’
4~2
4~3
44
4~i
4~4
52
6-2
7~1
7~2
7~3
7-4
7~4
7~5
‘~6
M
7Yz
J-7
7~8
7-9
7-9
7.10
7~12
7~:3
7-14
7-15
7-15
7-16
8-3
9-2
9.11
9-13
9-17
9-21
iv

LIST OF ILLUSTRATIONS (CONT.)
FIGURE TITLE PAGE
9-6 AC Converter, Schematic Diagram g-23
9-7 MotharBoard.SchematicDiagram............................................................... 9.25
9-a Analog Board, Schematic Diagram g-29
9-9 Display Board, Schematic Diagram g-33
LIST OF TABLES
TABLE TITLE PAGE
4-l
4-2
4-3
4-4
5-l
52
6-l
6-Z
6-3
6-4
6-5
7-1
7-2
7-3
7-4
6-l
6-2
8-3
9-4
86
6-5
a-7
a8
a-9
a10
6-11
6-12
El3
6-14
9-1
9-2
9-3
9-4
9-5
LineVoltagaSalection ........................................................................... 4-l
MaximumInput ............................................................................... 4-1
ResistanceRanges ............................................................................. 4-3
Maximum Four-Wire Test Lead Resistance. ............................................ ..... 4-4
FrontPanalProgramSummary ................................................................... 5-l
Data Point Times .................................................................. ....... 5-9
Recommended Test Equipment for Performance Verification ...................................... .. 6-l
DC Voltage Performance Check (2OV to 12OOV Rangel ......................................... .. 6-2
ACVoltageAccuracyChack ..................................................................... 62
ZeroReading .................................................................................. 6-3
ResistanceAccuracyChack ..................................................................... 6-3
SenlingDelays.SNontoTurnonoflntegrator.. ......................................... ........ 7-8
MamoryByteLocations...............................................................~..~ .... 7-10
FunctionsofLatchOutputs .................................................................... 7-13
Power Supply Component Identification. .............................................. ..... 7-15
Recommended Test Equipment for Calibration .................................................... 6-l
CalibrationProcaduras.................................................................~~~ ...... a-2
Fuse Replacement ............................................................................. 6-4
LineVoltagaSalaction................................................................~~~~ ..... 6-4
TestNumberSummarization ..................................................................... 6-6
Static Sensitive Devices ......................................................................... 8-5
Program 8 A/D Test-FET Switching Sequence ......................................... ....... ... 6.7
LinePowarChecks................................................................~...~ ....... a-a
AIDConvarterChacks ..................................................................... .~~ 6.6
Display Checks.. ............................................................................. 6.9
ACConvartarCheckslModel1910) ................................................................ 6.9
DCAnanuatorChacks.....................................................................~ .... 6.10
Ohms Source and Resistors Checks. .............................................................. 9-l 1
DigitalBoardChecks....................................................................~..~.~ 6-11
Modal192DrawingPackage..............................................................~..~..~ 9-1
AC Converter PC-496, Parts List ............................................................ ..... 9-3
MotharBoardPC-559,PartsList........................................................~~ ...... 9.4
Analog Board PC-560. PartsList ............................................................ .. 9.6
Display Board PC-530, Parts List ................................................................ 9-9
v/vi