Fluke 8842a Manual do Utilizador

®8842ADigital MultimeterInstruction ManualPN 879309Date December 1991Rev.3 7/96© 1999 Fluke Corporation, All rights reserved. Printed in USAAll produc

8842AInstruction Manualviii6-27. AC Signal Tracing... 6-

Measurement TutorialREDUCING THERMAL VOLTAGES44-9f4-05.wmfFigure 4-5. Burden Voltage Error Calculation4-14. REDUCING THERMAL VOLTAGESWhen making very

8842AInstruction Manual4-104. Use caution when handling the circuit under test.5. Wait for the circuit to reach thermal equilibrium. (Thermal voltag

Measurement TutorialAC VOLTAGE AND CURRENT MEASUREMENT44-11f4-06.wmfFigure 4-6. Waveform Comparison ChartSince average-responding meters have been in

8842AInstruction Manual4-124-18. Crest FactorCrest factors are useful for expressing the ability of an instrument to measure a variety ofwaveforms acc

Measurement TutorialAC VOLTAGE AND CURRENT MEASUREMENT44-13measurements, for instance, cannot be made with dc coupling. Remember, however, thatwhen th

8842AInstruction Manual4-14The zero-input error is quickly reduced when the input is increased. The rms convertererror (a dc error) and the internally

Measurement TutorialMAKING ACCURATE HIGH-RESISTANCE MEASUREMENTS44-15f4-10.wmfFigure 4-10. Shielding for Low Voltage MeasurementsFor low-level resista

8842AInstruction Manual4-16f4-12.wmfFigure 4-12. Leakage Resistance in High Resistance Measurement

5-1Chapter 5Theory of OperationTitle Page5-1. INTRODUCTION... 5-35-2. OVE

8842AInstruction Manual5-25-36. POWER SUPPLY... 5-255-37. IEEE-488 INTERF

ixList of FiguresFigure Title Page1-1. External Dimensions...

Theory of OperationINTRODUCTION55-35-1. INTRODUCTIONThis section presents an overall functional description of the 8842A, followed by adetailed circui

8842AInstruction Manual5-45-3. DETAILED CIRCUIT DESCRIPTIONThe following paragraphs give a detailed circuit description of each of the functionalbloc

Theory of OperationDC SCALING55-5f5-01.wmfFigure 5-1. Overall Functional Block Diagram

8842AInstruction Manual5-65-5. VDC ScalingScaling is performed in the VDC function by two precision resistors networks (Z301 andZ302). These componen

Theory of OperationDC SCALING55-7In the 20 mV, 200 mV and and 2V ranges, the input voltage is applied directly to the T/HAmplifier via Q310, Q311, and

8842AInstruction Manual5-85-9. TRACK/HOLD CIRCUITThe Track/Hold (T/H) circuit presents a stable voltage to the A/D Converter during theinput period of

Theory of OperationTRACK/HOLD CIRCUIT55-9f5-04.wmfFigure 5-4. Track/Hold Circuit Configurations

8842AInstruction Manual5-10f5-05.wmfFigure 5-5. Timing Diagram for One A/D Cycle5-10. Track ConfigurationIn the track configuration (Figure 5-4A), the

Theory of OperationPRECISION VOLTAGE REFERENCE55-115-11. Settling ConfigurationThe circuit assumes a settling configuration between the track and hol

8842AInstruction Manual5-12Resistor R701, precision resistor network Z701, and transistor/zener diode combinationU701 are produced as a matched set so

8842AInstruction Manualx4-12. Leakage Resistance in High Resistance Measurement... 4-165-1. Overall Functional

Theory of OperationOHMS PROTECTION55-13The second stage (U404, precision resistor network Z401, and analog switches U402 andU403) is a current amplifi

8842AInstruction Manual5-14f5-08.wmfFigure 5-8. Ohms Scaling

Theory of OperationA/D CONVERTER55-15The voltage sensed at the INPUT terminals is scaled as shown by the simplified switchtable in Figure 5-8. (Refer

8842AInstruction Manual5-16f5-09.wmfFigure 5-9. Analog-to-Digital ConverterThe conversion process is broken up into an autozero period followed by fiv

Theory of OperationA/D CONVERTER55-17f5-10.wmfFigure 5-10. First Remainder-Store PeriodThis five-interval process thus generates five nibbles which ar

8842AInstruction Manual5-18The bit-switches determine the output voltage of U102B by controlling the binary laddernetwork. The gain of U102B is set by

Theory of OperationKEYBOARD55-19f5-12.wmfFigure 5-12. Vacuum Fluorescent DisplayThe Digital Controller sequentially enables the G lines by applying +3

8842AInstruction Manual5-20f5-13.wmfFigure 5-13. Digital Controller Block Diagram

Theory of OperationDIGITAL CONTROLLER55-215-28. In-Guard MicrocomputerThe In-Guard Microcomputer (µC) is a single-chip Z8 microcomputer containing 4K

8842AInstruction Manual5-22f5-14.wmfFigure 5-14. Read/Write Timing Diagrams for Internal Bus

Contents (continued)xi9-7. IEEE-488 Interface PCA, Option -05... 9-159-8. True RMS AC

Theory of OperationDIGITAL CONTROLLER55-235-29. Function and Range ControlThe In-Guard µC configures the DC Scaling circuit, the Track/Hold circuit,

8842AInstruction Manual5-245-32. Keyboard/Display ControlKeyboard/Display Controller U212 communicates with the In-Guard µC over the internalbus. Duri

Theory of OperationPOWER SUPPLY55-25The circuit in Figure 5-15 has two stable states, corresponding to output high (+5V) andoutput low (0V). If the ou

8842AInstruction Manual5-265-37. IEEE-488 INTERFACE (OPTION -05)The IEEE-488 Interface has five major parts, as shown in the block diagram in Figure

Theory of OperationTRUE RMS AC (OPTION -09)55-275-41. Signal ConditioningThe SAMPLE COMPLETE and EXT TRIG signals (J903 and J904) are conditioned byU9

8842AInstruction Manual5-28U806A, U806B, and a voltage divider (R804 and R805) provide gain which is selectedfor each range by the analog switches in

Some semiconductors and custom IC's can bedamaged by electrostatic discharge duringhandling. This notice explains how you canminimize the chances

5. USE STATIC SHIELDING CONTAINERS FOR HANDLING AND TRANSPORT.6. DO NOT SLIDE S.S. DEVICES OVER ANY SURFACE.7. AVOID PLASTIC,VINYL AND STYROFOAM

6-1Chapter 6MaintenanceTitle Page6-1. INTRODUCTION... 6-36-2. PERFORMAN

8842AInstruction Manual6-26-35. EXTERNAL TRIGGER POLARITY SELECTION (Option -05 Only)6-366-36. TROUBLESHOOTING...

8842AInstruction Manualxii

MaintenanceINTRODUCTION66-3WARNINGTHESE SERVICE INSTRUCTIONS ARE FOR USE BY QUALIFIEDPERSONNEL ONLY. TO AVOID ELECTRIC SHOCK, DO NOTPERFORM ANY PROCED

8842AInstruction Manual6-4AC Calibrator Fluke 5700A and Fluke 5725AMinimum Required Accuracy (By Range)Frequency Range 1, 10, 100 mV11, 10, 100V21000V

MaintenancePERFORMANCE TEST66-5To initiate the self-tests, press the SRQ button for 3 seconds. The TEST annunciator willthen light up, and the 8842A w

8842AInstruction Manual6-6f6-01.wmfFigure 6-1. DC Calibration ConnectionsTable 6-2. DC Voltage TestDisplayed ReadingSLOW MEDIUM FASTSTEP RANGE INPUT(V

MaintenancePERFORMANCE TEST66-76-5. AC Voltage Test (Option -09 Only)The following procedure may be used to verify the accuracy of the VAC function:1

8842AInstruction Manual6-8Table 6-4. High-Frequency AC Voltage TestINPUT TEST LIMITS (IN VOLTS)STEPNUMBERRANGEVOLTAGE FREQUENCYERRORINCOUNTSMIN MAX1 2

MaintenancePERFORMANCE TEST66-9Table 6-5. Resistance TestError From Input1 (in counts)Step Range Input(Nominal)Slow Medium Fast2120Ω30Ω (short) ±40 ±6

8842AInstruction Manual6-106-8. AC Current Test (Option -09 Only)The following procedure may be used to test the mA AC function:1. Ensure the 8842A

MaintenanceCALIBRATION66-116-10. Basic Calibration ProcedureThe basic calibration procedure consists of the following four parts. These parts must b

8842AInstruction Manual6-12f6-03.wmfFigure 6-3. Calibration FunctionsThe following functions are inappropriate during calibration, and are thereforeun

1-1Chapter 1Introduction and SpecificationsTitle Page1-1. INTRODUCTION...

MaintenanceCALIBRATION66-132. Each time the 8842A prompts you for a reference source, apply the requested sourceto the HI and LO INPUT terminals, and

8842AInstruction Manual6-14The A/D Calibration procedure is an iterative process. Each pass through the procedureuses the constants stored previously

MaintenanceCALIBRATION66-15NOTETo use reference sources that differ from the prompted values, see StoringVariable Inputs later in this section.4. Aft

8842AInstruction Manual6-165. The calibration procedure is now completed. Exit the calibration mode by pressingthe CAL ENABLE switch, and attach a ca

MaintenanceCALIBRATION66-176-17. CALIBRATING INDIVIDUAL RANGESDuring Offset and Gain and High-Frequency AC Calibration, it is possible to calibratein

8842AInstruction Manual6-181. If you just completed the Offset and Gain or High-Frequency AC Calibration for anentire function (not just one range),

MaintenanceCALIBRATION66-19If ERROR 41 occurs, the most likely cause is that the reference input is incorrect (e.g.,has the wrong polarity). If the in

8842AInstruction Manual6-20readings. (In remote calibration, the averaged value can be stored in the controller.)Record the value.4. Select the "

MaintenanceCALIBRATION66-21Table 6-14. Commands Used During remote CalibrationFRONT PANELFEATURECORRESPONDINGCOMMANDCOMMENTSDisplay G2 Loads the calib

8842AInstruction Manual6-221. In remote calibration, you can store a 16-character message in the calibrationmemory which can be read by the system co

8842AInstruction Manual1-21-1. INTRODUCTIONThis manual provides complete operating instructions and service information for the8842A. If you want to g

MaintenanceCALIBRATION66-236-24. TIMING CONSIDERATIONSTable 6-15. Error Numbers Which Are Displayed When Commands Are Not ValidCALIBRATION MODECOMMAN

8842AInstruction Manual6-24The C0 command can take up to 22 seconds. If during this time the controller continuesto send the 8842A more commands, the

MaintenanceDISASSEMBLY PROCEDURE66-25f6-05.wmfFigure 6-5. Example A/D Calibration Program6-27. DISASSEMBLY PROCEDUREWARNINGTO AVOID ELECTRIC SHOCK, RE

8842AInstruction Manual6-266-28. Case Removal1. Remove the grounding screw from the bottom of the case. Remove two rear bezelmounting screws. (See Fi

MaintenanceDISASSEMBLY PROCEDURE66-27f6-06_2.wmfFigure 6-6. 8842A Disassembly (cont)

8842AInstruction Manual6-28f6-06_3.wmfFigure 6-6. 8842A Disassembly (cont)

MaintenanceDISASSEMBLY PROCEDURE66-29f6-06_4.wmfFigure 6-6. 8842A Disassembly (cont)

8842AInstruction Manual6-306-29. True RMS AC PCA Removal (Option -09 Only)The True RMS AC PCA should be removed by reversing the last three steps in

MaintenanceDISASSEMBLY PROCEDURE66-31b. Unplug the ribbon cable from the Main PCA and lift out the LINE SET PCA.9. Remove the push rod for the CAL E

8842AInstruction Manual6-326-32. Front Panel Disassembly1. Holding the chassis vertically (with the front panel downward), remove the mountingscrews

Introduction and SpecificationsSPECIFICATIONS11-31-4. SPECIFICATIONSSpecifications for the 8842A are given in Table 1-1. External dimensions are shown

MaintenanceREASSEMBLY PROCEDURE66-33NOTEWhen installing the Main PCA, guide the rear ribbon cable around theshield connected to the rear panel so that

8842AInstruction Manual6-34f6-07.wmfFigure 6-7. Front Panel Disassembly

MaintenanceREASSEMBLY PROCEDURE66-35f6-08.wmfFigure 6-8. Removing the Display WindowCAUTIONMake certain that the CAL ENABLE switch shaft is in the out

8842AInstruction Manual6-36WARNINGTO AVOID ELECTRIC SHOCK, ENSURE THATTHE GROUNDING SCREW IS FIRMLYATTACHED TO THE CASE BOTTOM.6-34. INTERNAL FUSE RE

MaintenanceTROUBLESHOOTING66-37If the display lights up, perform the self-test by pressing the SRQ button for 3 seconds.(Remember, the input terminals

8842AInstruction Manual6-38Table 6-16. Overall State Tablet6-16_1.wmf

MaintenanceTROUBLESHOOTING66-39Table 6-16. Overall State Table (cont)t6-16_2.wmf

8842AInstruction Manual6-40Table 6-17. Circuitry Tested by the Analog Self-Testst6-17.wmfSome failures will cause many self-tests to fail. If this occ

MaintenanceTROUBLESHOOTING66-41A failure in the instrument may cause the 8842A to display random patterns or nothing atall. Usually, analog circuit fa

8842AInstruction Manual6-426-39. Self-Test DescriptionsTable 6-18. Self-Test VoltagesTEST NUMBER TEST POINT VOLTAGE1 TP803 ±5 mV dc2 TP803 ±5 mV dc3 T

8842AInstruction Manual1-4Operating CharacteristicsTEMPERATURE COEFFICIENT ...<(0.0006% of reading + 0.3 Count) per °C from 0°C to 18°Cand

MaintenanceTROUBLESHOOTING66-43Configures the 8842A in the mA DC function and the slow reading rate, and measuresthe reading across the 0.1Ω current s

8842AInstruction Manual6-44These tests put the 8842A in the respective range of the 2-wire ohms function. Theycheck that each range of the Ohms Curren

MaintenanceTROUBLESHOOTING66-45• TEST 28: External Program Memory (U222)A two-byte check sum is calculated over the entire 4K External Program Memory

8842AInstruction Manual6-46programmed as inputs to prevent contentions between them and the outputs from otherICs which drive them. Data coming into a

MaintenanceTROUBLESHOOTING66-471. Power supplies: +5V dc at U202-1; 0V dc U202-11.2. µC clock output: 8 MHz at U202-2,-3.3. Trigger line U202-40 (

8842AInstruction Manual6-4816, -18, -21, -25 are the same as Waveform B. The waveforms should be interruptedevery 1.5 sec for 0.2 sec due to interrupt

MaintenanceTROUBLESHOOTING66-49possible to freeze the display, it should still be possible to observe the waveforms atU215, U213, U221, and U211 as de

8842AInstruction Manual6-50Check for the same waveforms at outputs U215-11 through U215-18. (However, the highlevel should be approximately 30V.) If t

MaintenanceTROUBLESHOOTING66-516-56. Hex Inverter (U221)Check that U221-5 is the same as STROBE ZERO and that U221-6 is STROBE ZEROinverted.6-57. Qua

8842AInstruction Manual6-52Table 6-20. Analog Control DevicesDEVICE REF. DES.Relay Buffer U201Quad Comparator U305Quad Analog Switch U301Quad Analog S

Introduction and SpecificationsSPECIFICATIONS11-5AccuracyNORMAL (s) READING RATE ... ±(% of Reading + Number of Counts).For sinewave inpu

MaintenanceTROUBLESHOOTING66-53Table 6-21. Analog Control Logic Statest6-21.wmfNext move to U305-5 and repeat. The slow reading rate gives the followi

8842AInstruction Manual6-54If the instrument is not in the slow reading rate, it gives the following pattern at U305-5:000000 00000 000000 0000000 000

MaintenanceTROUBLESHOOTING66-55Table 6-22. DC Scaling and Track/Hold Supply VoltagesPIN OR DEVICE SUPPLY VOLTAGE PIN OR DEVICE SUPPLY VOLTAGEU301-6 +5

8842AInstruction Manual6-566-63. Track/Hold TroubleshootingIf a problem is suspected in the Track/Hold (T/H) circuit, first check the power supplyvolt

MaintenanceTROUBLESHOOTING66-57f6-13.wmfFigure 6-13. Typical Output Waveforms for Track/Hold Circuit (TP103)To test whether the Ohms Current Source is

8842AInstruction Manual6-58If the ohms functions do not work in any range, check the supplies at U401 (+/-15V),U404 (+30V and -5V), U402 (+15V, +5V, a

MaintenanceTROUBLESHOOTING66-596-66. A/D Converter TroubleshootingIf there is a failure of the A/D Converter, all power supply levels should be check

8842AInstruction Manual6-60f6-15.wmfFigure 6-15. Waveforms at U101-24 and U101-25f6-16.wmfFigure 6-16. Typical Bus Data Line WaveformThe waveform at t

MaintenanceTROUBLESHOOTING66-61problem between the A/D Converter and the In-Guard µC can cause erroneous or noisyreadings or offsets. Similar problems

8842AInstruction Manual6-62f6-17.wmfFigure 6-17. Waveforms at TP102 for Several Inputs on 2V DV RangeSince power supply problems can produce symptoms

8842AInstruction Manual1-6CURRENTInput CharacteristicsRESOLUTIONRANGE FULL SCALE 5½DIGITS5½ DIGITS 4½ DIGITS1200 mA 2199.999 mA 1 µA 10 µA2000 mA 1999

MaintenanceTROUBLESHOOTING66-63f6-18.wmfFigure 6-18. Calculating the A/D Reading From TP102 WaveformTable 6-23. Power Supply VoltagesLIMITS (in volts)

8842AInstruction Manual6-64The True RMS AC PCA, if installed, uses +5V and +/-15V. If there is a problem withone of those supplies, first disconnect t

MaintenanceTROUBLESHOOTING66-65f6-19.wmfFigure 6-19. Option -05 Service PositionTable 6-24. Diagnostic ModesSWITCHESA3 A2 A1CONFIGURATION1 0 1 Static,

8842AInstruction Manual6-66Table 6-25. I/O Port ConfigurationsCONFIGURATION CONFIGURATIONPORT BITStaticDynamicRead/WritePORT BITStaticDynamicRead/Writ

MaintenanceTROUBLESHOOTING66-674. Position the True RMS AC PCA vertically as shown in Figure 6-20 and latch it inplace by pressing the bottom two nyl

8842AInstruction Manual6-68f6-20.wmfFigure 6-20. Option -09 Service PositionIf the signal at the input to U801A (pin 5) is incorrect, U804 may be defe

MaintenanceTROUBLESHOOTING66-69Table 6-28. Truth Table for U804 and K2PIN OR DEVICERANGEU804-1 U804-8 U804-9 U804-16 K22000 mA 10110200 mV 100102V 111

8842AInstruction Manual6-70It is safe to force one control line at a time high (+5V) or low (0V) to test the individualswitches in U808. (The on resis

MaintenanceINTERNAL CLEANING66-716-78. Cleaning After SolderingCAUTIONT.M.C. Cleaner and similar products can can attack the nylonlatches and other p

8842AInstruction Manual6-72

Introduction and SpecificationsSPECIFICATIONS11-7MEDIUM AND FAST READING RATES...In medium rate, add 50 counts to number of counts. In fastreadin

7-1Chapter 7List of Replaceable PartsTitle Page7-1. INTRODUCTION...7-37-2

8842AInstruction Manual7-2

List of Replaceable PartsINTRODUCTION77-37-1. INTRODUCTIONThis section contains an illustrated list of replaceable parts for the 8842A. Parts are list

8842AInstruction Manual7-47-4. NEWER INSTRUMENTSChanges and improvements made to the instrument are identified by incrementing therevision letter mar

List of Replaceable PartsSERVICE CENTERS77-5Manual Status InformationREF OF OPTION NO. ASSEMBLY FLUKE PART NO. REVISION LEVELA1A20509Main PCADisplay P

8842AInstruction Manual7-6f7-01_1.wmfFigure 7-1. 8842A Digital Multimeter

List of Replaceable PartsSERVICE CENTERS77-7f7-01_2.wmfFigure 7-1. 8842A Digital Multimeter (cont)

8842AInstruction Manual7-8f7-01_3.wmfFigure 7-1. 8842A Digital Multimeter (cont)

List of Replaceable PartsSERVICE CENTERS77-9f7-01_4.wmfFigure 7-1. 8842A Digital Multimeter (cont)

8842AInstruction Manual7-10Table 7-2. A1 Main PCAReferenceDesignatorDescription Fluke StockNoTot Qty NotesAR701 REF AMP SET 759290 1C101-103,C311 CAP,

8842AInstruction Manual1-8AccuracyNORMAL (S) READING RATE...±(% of Reading + Number of Counts)1.RANGE 24 HOURS 23±1°C 90 DAY 23±5°C 1 YEAR

List of Replaceable PartsSERVICE CENTERS77-11Table 7-2. A1 Main PCA (cont)ReferenceDesignatorDescription Fluke StockNoTot Qty NotesJ203,J204 CABLE, DI

8842AInstruction Manual7-12Table 7-2. A1 Main PCA (cont)Reference DesignatorDescription Fluke StockNoTot Qty NotesR413 RES,MF,4.99M,+-1%,0.125W,100PP

List of Replaceable PartsSERVICE CENTERS77-13f7-03.wmfFigure 7-2. A1 Main PCA

8842AInstruction Manual7-14Table 7-3. A2 Display PCA

List of Replaceable PartsSERVICE CENTERS77-15f7-03.wmfFigure 7-3. A2 Display PCA

8842AInstruction Manual7-16Supply Codes for Manufacturerssupply_1.wmf

List of Replaceable PartsSERVICE CENTERS77-17Supply Codes for Manufacturers (cont)supply_2.wmf

8842AInstruction Manual7-18service_1.wmfFigure 7-4. Service Centers

List of Replaceable PartsSERVICE CENTERS77-19service_2.wmfFigure 7-4. Service Centers (cont)

8842AInstruction Manual7-20

Introduction and SpecificationsSPECIFICATIONS11-9Reading RatesREADING RATES WITH INTERNAL TRIGGER (readings per second)POWER LINE FREQUECNCY1RATE50 Hz

8-1Chapter 8Options and AccessoriesTitle Page8-1. INTRODUCTION... 8-38-

8842AInstruction Manual8-2

Options and AccessoriesINTRODUCTION88-38-1. INTRODUCTIONA number of options and accessories are available which can enhance the 8842A’scapabilities an

8842AInstruction Manual8-48-2. ACCESSORIESAccessories include a variety of rack-mounting kits, cables, test leads, and probes. Theaccessories include

Options and AccessoriesACCESSORIES88-58-10. Current Shunt (80J-10)The 80J-10 current shunt extends ac or dc current measurement up to 10A continuous,

8842AInstruction Manual8-6

805-1Chapter 805Option –05 IEEE-488 InterfaceTitle Page805-1. INTRODUCTION...

8842AInstruction Manual805-2

Option –05 IEEE-488 InterfaceINTRODUCTION805-3805-1. INTRODUCTIONThe IEEE-488 Interface turns the 8842A into a fully programmable instrument for usewi

8842AInstruction Manual805-43. Disconnect the ribbon cable from the plastic rear panel insert by pulling the tabson either side of the ribbon cable c

8842AInstruction Manual1-10EXTERNAL TRIGGER TIMING CHARACTERISTICSThe following diagram shows the nominal timing for the various processes which take

Option –05 IEEE-488 InterfaceLIST OF REPLACEABLE PARTS805-5f805-1_1.wmfFigure 805-1. Installing Option -05

8842AInstruction Manual805-6f805-1_2.wmfFigure 805-1. Installing Option –05 (cont)

Option –05 IEEE-488 InterfaceLIST OF REPLACEABLE PARTS805-7Table 805-1. Option -05A IEEE-488 Interface PCA

8842AInstruction Manual805-8f805-2.wmfFigure 805-2. IEEE-488 Interface PCA

809-1Chapter 809Option –09 True RMS ACTitle Page809-1. INTRODUCTION...

8842AInstruction Manual809-2

Option –09 True RMS ACINTRODUCTION809-3809-1. INTRODUCTIONThe True RMS AC option gives the 8842A the ability to make ac voltage and currentmeasurement

8842AInstruction Manual809-4809-3. OPERATING INSTRUCTIONSFor operating instructions, refer to Section 2. For ac measurement considerations, refer toSe

Option –09 True RMS ACLIST OF REPLACEABLE PARTS809-5f809-1.wmfFigure 809-1. Installing Option -09

8842AInstruction Manual809-6Table 809-1. Option -09 True RMS AC PCAt809-1.wmf

Introduction and SpecificationsSPECIFICATIONS11-11GENERALCOMMON MODE VOLTAGE...1000V dc or peak ac, or 700V rms ac from any input to ea

Option –09 True RMS ACLIST OF REPLACEABLE PARTS809-7f809-2.wmfFigure 809-2. True RMS AC PCA

8842AInstruction Manual809-8

9-1Chapter 9Schematic Diagrams

8842AInstruction Manual9-2

Schematic Diagrams99-3f9-01_1.wmfFigure 9-1. Main PCA, DC Scaling and F/R Switch

8842AInstruction Manual9-4f9-01_2.wmfFigure 9-1. Main PCA, DC Scaling and F/R Switch (cont.)

Schematic Diagrams99-5f9-02_1.wmfFigure 9-2. Main PCA, A/D Converter

8842AInstruction Manual9-6f9-02_2.wmfFigure 9-2. Main PCA, A/D Converter (cont.)

Schematic Diagrams99-7f9-03_1.wmfFigure 9-3. Main PCA, Ohms Current Source

8842AInstruction Manual9-8f9-03_2.wmfFigure 9-3. Main PCA, Ohms Current Source (cont.)

2-1Chapter 2Operating InstructionsTitle Page2-1. INTRODUCTION...2-22-2. I

Schematic Diagrams99-9f9-04_1.wmfFigure 9-4. Main PCA, Digital

8842AInstruction Manual9-10f9-04_2.wmfFigure 9-4. Main PCA, Digital (cont.)

Schematic Diagrams99-11f9-05_1.wmfFigure 9-5. Main PCA, Power Supply

8842AInstruction Manual9-12f9-05_2.wmfFigure 9-5. Main PCA, Power Supply (cont.)

Schematic Diagrams99-13f9-06_1.wmfFigure 9-6. Display PCA

8842AInstruction Manual9-14f9-06_2.wmfFigure 9-6. Display PCA (cont.)

Schematic Diagrams99-15f9-07_1.wmfFigure 9-7. IEEE-488 Interface PCA

8842AInstruction Manual9-16f9-07_2.wmfFigure 9-7. IEEE-488 Interface PCA (cont.)

Schematic Diagrams99-17f9-08_1.wmfFigure 9-8. IEEE-488 Interface PCA, Option -08

8842AInstruction Manual9-18f9-08_2.wmfFigure 9-8. IEEE-488 Interface PCA, Option –08 (cont.)

8842AInstruction Manual2-22-1. INTRODUCTIONThis section provides instructions for installing and operating the 8842A. Refer toSection 4 for measuremen

Operating InstructionsINSTALLATION22-32-5. Adjusting the HandleThe handle provides two viewing angles for bench-top use. To adjust its position, pull

8842AInstruction Manual2-4f2-04.wmfFigure 2-4. Installing the Single Rack Mount Kit2-7. OPERATING FEATURES2-8. Power-Up FeaturesWhen the 8842A is tur

iTable of ContentsChapter Title Page1 Introduction and Specifications... 1-11-1. INTRODUCTION...

Operating InstructionsOPERATING FEATURES22-5Note that the VAC and mA AC functions are available only with the True RMS ACoption. If this option is abs

8842AInstruction Manual2-6MTRIG triggers a new reading.Enabled in external trigger mode.EXT TRIG toggles between internaland external trigger modesRAT

Operating InstructionsOPERATING FEATURES22-7Line VoltageSelection SwitchesPower-Line FusePower-Line Cord ConnectorHI and LO INPUTTerminalsIEEE-488 Int

8842AInstruction Manual2-82-10. Display FeaturesThe 8842A features a vacuum fluorescent display with a numeric field and annunciators.The annunciators

Operating InstructionsOPERATING FEATURES22-9Table 2-1. Error CodesERRORCODEMEANING ERROR CODE MEANINGANALOG SELF-TEST ERRORS OPERATION ERRORS1 200 VAC

8842AInstruction Manual2-102-12. Overrange IndicationAn input is overrange if it exceeds the full scale of the selected range. In most ranges, the8842

Operating InstructionsOPERATING FEATURES22-112-16. MANUAL RANGEIn manual range, the 8842A remains fixed in the selected range until you select another

8842AInstruction Manual2-12In the continuous trigger mode, the actual number of readings displayed per second foreach reading rate is determined by th

Operating InstructionsMAKING MEASUREMENTS22-132-24. MAKING MEASUREMENTS2-25. Input Overload Protection LimitsWARNINGTO AVOID SHOCK HAZARD AND/OR INST

8842AInstruction Manual2-14To replace the front panel fuse, first remove the test leads. Then press in the lip of the 2Ainput terminal slightly and ro

8842AInstruction Manualii2-28. Current Fuse Protection... 2-132-29. Offset Measuremen

Operating InstructionsEXTERNAL CLEANING22-15f2-09.wmfFigure 2-9. Measuring Voltage and Resistancef2-10.wmfFigure 2-10. Measuring Current2-30. EXTERNAL

8842AInstruction Manual2-16

3-1Chapter 3Remote ProgrammingTitle Page3-1. INTRODUCTION...3-33-2. CAPAB

8842AInstruction Manual3-23-35. ? (Single-Trigger Command)...3-203-36. INPUT SYNTAX...

Remote ProgrammingINTRODUCTION33-3NOTEThis section contains programming instructions for use with the IEEE-488Interface (Option -05). For installation

8842AInstruction Manual3-4ADDRESSTALKONLYA5 A4 A3 A2 A1 ADDRESSTALKONLYA5 A4 A3 A2 A1 ADDRESSTALKONLYA5 A4 A3 A2 A100 0 0 0000 11 001011 22 0 1011001

Remote ProgrammingAN OVERVIEW OF REMOTE OPERATION33-5f3-02.wmfFigure 3-2. Remote Operation Block Diagram

8842AInstruction Manual3-6Information is transferred between blocks by device-dependent commands. Eachcommand is shown next to an arrowhead which indi

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-7RANGE COMMANDSR0 Autorange OnR1 200 mV, 200ΩR2 2V, 2 kΩR3 20V, 20 kΩR4 200V, 200 kΩ, 200 mAR5 1000V

8842AInstruction Manual3-8FUNCTON COMMANDS TERMINATOR COMMANDSF1 VDC (Default) W0 Enable CR LF EOI (Default)F2 VAC W1 Enable CR LF OnlyF3 2 WIRE kΩ W2

Contents (continued)iii3-50. The Serial Poll Register ... 3-273-51. The SRQ Mask...

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-9Device-dependent commands are device-dependent messages. For the 8842A to receivethem, they must be

8842AInstruction Manual3-103-10. Fn (Function Commands)The function commands duplicate the front panel function buttons. The 8842A defaults toF1 on p

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-11Table 3-1. Status DataCOMMANDOUTPUT STRING MEANINGG0 Frst F = 1 – 6 as in Funtion comm

8842AInstruction Manual3-123-12. G0 (Get Instrument Configuration)The G0 command copies the 8842A function, range, reading rate, and trigger mode int

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-133-15. G3 (Get User-Defined Message)The G3 command loads the output buffer with the user-defined me

8842AInstruction Manual3-143-17. G5 (Get IAB Status)The G5 command loads the output buffer with the IAB status in the format shown inFigure 3-6. As T

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-153-20. G8 (Get Instrument Identification)The G8 command copies the 8842A instrument identification

8842AInstruction Manual3-16"N3120 P0" Identical to F3 R1 S2 T0. Selects 2 WIRE kΩ function, 200Ω range,fast sample rate, continuous trigger.

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-17etc. All of these strings result in the same value being used for the next calibration step.For com

8842AInstruction Manual3-183-29. Tn (Trigger Mode Commands)The Trigger Mode commands duplicate the front panel EX TRIG button. In addition, thecomman

8842AInstruction Manualiv5-15. OHMS CURRENT SOURCE... 5-125-16. OHMS PROTECTION...

Remote ProgrammingDEVICE-DEPENDENT COMMAND SET33-19The trigger mode can be read using the G0 command. The 8842A defaults to T0 on bothpower-up and any

8842AInstruction Manual3-20Error messages are indicated by an exponent of +21. For more about error messages, seeparagraph 3-40.Since the 8842A is res

Remote ProgrammingINPUT SYNTAX33-213-37. Definitions• Output commands: Commands which load data into the output buffer. The outputcommands are: the G

8842AInstruction Manual3-22DEVICE-DEPENDENT MESSAGESSingle-character CommandsBn Cn Dn Fn Gn Pn Rn Sn Wn Xn Yn Zn Each of these commands requires the s

Remote ProgrammingINPUT SYNTAX33-23Illegal commands (e.g., F9) generate an error message, but are otherwise ignored, and donot affect the instrument’s

8842AInstruction Manual3-24In this incorrect example, the INPUT statement is located incorrectly for reading themeasurement data from line 100. The ne

Remote ProgrammingOUTPUT DATA33-25Because the 8842A gives priority to input processing, it completely processes allcharacters in the input buffer befo

8842AInstruction Manual3-26NOTEIn the fast (F) reading rate, the least significant digit is always zero, andshould be disregarded when interpreting ac

Remote ProgrammingSERVICE REQUESTS33-271. Status data (from G0, G1, G3, G4, G5, G6, G7 and G8)2. Error messages (if an error exists)3. Numeric data

8842AInstruction Manual3-28BIT: 8 7 6 5 4 3 2 10 RQS ANYERRORDATAAVAILIBLECAL STEPCOMPLETEFRONTPANEL SRQ0 OVER-RANGEDECIMALVALUE:64 32 16 8 4 2 1Bit N

Contents (continued)v6-20. TOLERANCE CHECK... 6-186-21. AC CALIBRATION AT OTHER FREQUENCIE

Remote ProgrammingINTERFACE MESSAGES33-29The SRQ mask can enable any combination of serial poll register bits 1 through 6. Its six-bit binary represen

8842AInstruction Manual3-30IFC Interface Clear -- A uniline message which clears only the interface (not the8842A) by placing it in a known quiescent

Remote ProgrammingREMOTE CALIBRATION33-316. Configure the 8842A with the front panel controls.The 8842A reads the TALK ONLY bit switch on power-up an

8842AInstruction Manual3-32Table 3-3. Immediate-Mode Commands for Various ControllersFUNTIONPERFORMEDFLUKE-BASIC on1720A or 1722AHP-HPL onHP9825Calcul

Remote ProgrammingEXAMPLE PROGRAMS33-33f3-10.wmfFigure 3-9. Example Program

8842AInstruction Manual3-34f3-11.wmfFigure 3-10. Example Program: Taking Readings with Local Control

Remote ProgrammingEXAMPLE PROGRAMS33-35f3-12.wmfFigure 3-11. Example Program: Using the Serial Poll Register

8842AInstruction Manual3-36f3-13.wmfFigure 3-12. Example Program: Record Errors During Selftest

Remote ProgrammingEXAMPLE PROGRAMS33-37f3-14_01.wmfFigure 3-13. Example Programs: Using the IBM PC

8842AInstruction Manual3-38f3-14_01.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manualvi8-5. Replacement Test Leads (TL70A)... 8-48-6. Deluxe Test Lead Kits (Y8134).

Remote ProgrammingEXAMPLE PROGRAMS33-39f3-14_02.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manual3-40f3-14_03.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

Remote ProgrammingEXAMPLE PROGRAMS33-41f3-14_04.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manual3-42f3-14_05.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

Remote ProgrammingEXAMPLE PROGRAMS33-43f3-14_06.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manual3-44f3-14_07.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

Remote ProgrammingEXAMPLE PROGRAMS33-45f3-14_08.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manual3-46f3-14_09.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

Remote ProgrammingEXAMPLE PROGRAMS33-47f3-14_10.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

8842AInstruction Manual3-48f3-14_11.wmfFigure 3-14. Example Programs: Using the IBM PC (cont)

viiList of TablesTable Title Page2-1. Error Codes...

Remote ProgrammingEXAMPLE PROGRAMS33-49Table 3-4. ASCII/IEEE Std 488-1978 Bus Codes

8842AInstruction Manual3-50NOTEFor the examples using the Fluke 1720A or 1722A, the 8842A is pluggedinto port 0. The port is initialized by the INIT s

4-1Chapter 4Measurement TutorialTitle Page4-1. INTRODUCTION...4-24-2. DC

8842AInstruction Manual4-24-1. INTRODUCTIONThis section discusses considerations and techniques to help you use the 8842Aeffectively. Among other thin

Measurement TutorialDC VOLTAGE MEASUREMENT44-3The input impedance of the 8842A is 10 MΩ in the 200V and 1000V dc ranges, and isgreater than 10,000 MΩ

8842AInstruction Manual4-43. Allow the displayed reading to settle.4. Press the OFFSET button.5. Remove the resistor.6. Proceed with the desired m

Measurement TutorialRESISTANCE MEASUREMENT44-5The test current and full-scale voltage for each resistance range are shown in Table 4-1.Since the HI IN

8842AInstruction Manual4-6f4-04.wmfFigure 4-4. Wire Ohms MeasurementTable 4-1. Ohms Test CurrentRANGE TEST CURRENT FULL SCALE VOLTAGE20Ω 1 mA 0.02V200

Measurement TutorialRESISTANCE MEASUREMENT44-7NOTEIn the 2 MΩ and 20 MΩ ranges of 4-wire ohms, the voltage across theunknown resistance is sensed betw

8842AInstruction Manual4-84-12. A PRECISION CURRENT SOURCEThe ohms current source (the internal current source used in the ohms functions) makes ause