8842A
Page
 Table of Contents
 Remote Programming
8842A
 Measurement Tutorial
 Maintenance
 List of Replaceable Parts
 Schematic Diagrams
 List of Tables
 805-7
 List of Figures
 805-8
 IEEE-488 Interface PCA, Option True RMS AC PCA, Option
 Xii
 Introduction and Specifications
 Introduction
Options and Accessories
8842A Digital Multimeter
 Specifications
 Rate
Peak NM Signal
Filter
True RMS AC Voltage Option 8842A-09
 Fundamental Frequency
Frequency
Crest Factor
For Inputs
 Full Scale 5½ Digits
Current
½ Digits
 Through Unknown
Range Full Scale Resolution Current ½ Digits
 Hours 23±1C
 Automatic Settling Time Delay
Rate Power Line FREQUECNCY1
Autoranging
Function
 Conversion Time ms 50 Hz 60 Hz 400 Hz
External Trigger Timing Characteristics
 General
Power
 Operating Instructions
 Installing the Power-Line Fuse
Installation
Connecting to Line Power
 Rack Mounting Kits
Adjusting the Handle
 Power-Up Features
Operating Features
Front and Rear Panel Features
 Operating Features
 Local button causes the 8842A to display its
 Rear Panel Features
 Error Messages
Display Features
 Meaning Error Code
Error Code
 Overrange Indication
Diagnostic Self-Tests
Ranging
Autorange
 External Trigger Mode
Continuous Trigger Mode
Manual Range
Triggering
 External Trigger Input Option -05 Only
Automatic Settling Time Delay
Sample Complete Output Option -05 Only
 Input Overload Protection Limits
Making Measurements
Measuring Voltage and Resistance
Measuring Current
 Offset Measurements
 Measuring Voltage and Resistance
External Cleaning
 8842A
 Remote Programming
 Measurement Data Overrange Indication Error Messages
 Capabilities
BUS SET-UP Procedure
 IEEE-488 Address Selection
AN Overview of Remote Operation
 AN Overview of Remote Operation
 ExampleExplanation
DEVICE-DEPENDENT Command SET
 DEVICE-DEPENDENT Command SET
 Device-Dependent Command Set
 Cn Calibration Commands
Bn Offset Commands
Dn Display Commands
 Get Commands
Fn Function Commands
 Meaning
Command Output String
 13. G1 Get SRQ Mask
12. G0 Get Instrument Configuration
14. G2 Get Calibration Prompt
 16. G4 Get Calibration Status
15. G3 Get User-Defined Message
 17. G5 Get IAB Status
19. G7 Get Error Status
18. G6 Get YW Status
 Put Commands
Numeric Entry Command
23. P0 Put Instrument Configuration
20. G8 Get Instrument Identification
 25. P2 Put Calibration Value
24. P1 Put SRQ Mask
 Sn Reading Rate Commands
Rn Range Commands
26. P3 Put User-Defined Message
 Trigger Selection Logic Diagram
Tn Trigger Mode Commands
 31. X0 Clear Error Register Command
Wn Terminator Commands
Yn Suffix Commands
33. Z0 Self-Test Command
 35. ? Single-Trigger Command
Device-Clear Command
Input Syntax
 Input Processing
Definitions
 DEVICE-DEPENDENT Messages
ERROR-PRODUCING Characters
Interface Messages
 Incorrect example
Syntax Rules
 Loading Output Data
Output Data
 Overrange Indication Error Messages
Numeric Data and Error Messages
Types of Output Data
Measurement Data
 Overrange Indication
Error Messages
Status Data
Output Priority
 Serial Poll Register
Service Requests
 Set
SRQ Mask
 Interface Messages
Universal Commands
Address Messages
 Addressed Commands
TALK-ONLY Mode
 Remote Calibration
Immediate Mode Commands
Timing Considerations
 Example Programs
Immediate-Mode Commands for Various Controllers
 Example Programs
 10. Example Program Taking Readings with Local Control
 11. Example Program Using the Serial Poll Register
 12. Example Program Record Errors During Selftest
 13. Example Programs Using the IBM PC
 14. Example Programs Using the IBM PC
 F3-1402.wmf
 F3-1403.wmf
 F3-1404.wmf
 F3-1405.wmf
 F3-1406.wmf
 F3-1407.wmf
 F3-1408.wmf
 F3-1409.wmf
 F3-1410.wmf
 F3-1411.wmf
 ASCII/IEEE Std 488-1978 Bus Codes
 8842A
 Measurement Tutorial
 DC Voltage Measurement
Circuit Loading Error
 Measuring Input Bias Current Error
Input Bias Current Error
 Resistance Measurement
Wire Ohms
 Correcting for Test Lead Resistance in 2-Wire Ohms
 Full Scale Voltage
Test Current
 Testing Electrolytic Capacitors
Testing Diodes
Applications of the Ohms Functions
 Precision Current Source
DC Current Measurement
 Reducing Thermal Voltages
Burden Voltage Error Calculation
 True RMS Measurement
AC Voltage and Current Measurement
Waveform Comparison
 AC Voltage and Current Measurement
 AC-Coupled AC Measurements
Crest Factor
 Combined AC and DC Measurements
Zero-Input VAC Error
Bandwidth
 20Ω Ranges
Reduction of Zero-Input Error
 10. Shielding for Low Voltage Measurements
Making Accurate HIGH-RESISTANCE Measurements
 12. Leakage Resistance in High Resistance Measurement
 Theory of Operation
 True RMS AC Option VAC Scaling MA AC Scaling
 Overall Functional Description
 DC Scaling
Detailed Circuit Description
 DC Scaling
 DC Scaling VDC and mA DC
VDC Scaling
 MA DC Scaling
VDC Protection
Analog Filter
 Track/Hold Amplifier
TRACK/HOLD Circuit
 TRACK/HOLD Circuit
 Timing Diagram for One A/D Cycle
Track Configuration
 Hold Configuration
Settling Configuration
Pre-Charge Configuration
Precision Voltage Reference
 Ohms Current Source
Ohms Current Source
 Ohms Functions
Ohms Protection
 Ohms Scaling
 20. A/D Converter
 Analog-to-Digital Converter
 Precision DAC
Timing/Data Control
 Display
Bootstrap Supplies
23. A/D Amplifier
 Digital Controller
Keyboard
 13. Digital Controller Block Diagram
 In-Guard Microcomputer
 14. Read/Write Timing Diagrams for Internal Bus
 Function and Range Control
Slow Medium Fast Power Line Frequency
30. A/D Control and Computation
Calibration Correction
 Guard Crossing
Troubleshooting Modes
Keyboard/Display Control
Guard-Crossing Communication
 Power Supply
 Out-Guard Microcomputer
IEEE-488 Interface Option
Guard Crossing
Bus Interface Circuitry
 IEEE-488 Interface Power Supply
Signal Conditioning
VAC Scaling
 Frequency Response Trimming
MA AC Scaling
True RMS AC-to-DC Conversion
 Static awareness
 Dow Chemical
 Maintenance
 External Trigger Polarity Selection Option -05 Only
 Instrument Type
Minimum Specifications Recommended Model
 Frequency Range Minimum Required Accuracy All Ranges
Performance Test
 DC Voltage Test
 Slow Medium Fast MIN MAX
Step Range Input
 Voltage Frequency
AC Voltage Test Option -09 Only
 New Offset must be stored for each new range selected
Resistance Test
 Displayed Reading
DC Current Test
Slow Medium MIN MAX
Fast MIN MAX
 AC Current Test Option -09 Only
Calibration
Step Number Range
Input Current Frequency
 Initial Procedure
Basic Calibration Procedure
 Calibration Functions
12. A/D Calibration
 Step Displayed Prompt
L O W a B L E Error
Step Input
 Step
Offset and Gain Calibration
Displayed Prompt VDC VAC1
 HIGH-FREQUENCY AC Calibration
 Storing Variable Inputs
Advanced Features and Special Considerations
Step Displayed PROMPT1,2
 Calibrating Individual Ranges
Procedure Function LOW Prompt High Prompt
Verifying Calibration
 Tolerance Check
Erasing Calibration Memory
 Optimizing USE of the 5450A
AC Calibration AT Other Frequencies
Calibration
Tolerance
 Optimizing Use of the 5450A
Remote Calibration
 Corresponding Command
Front Panel Feature
Comments
 8842A
 Timing Considerations
 Example Calibration Program
Remote Erasure
 Example A/D Calibration Program
Disassembly Procedure
 Case Removal
A Disassembly
 F6-062.wmf
 F6-063.wmf
 F6-064.wmf
 IEEE-488 Interface PCA Removal Option -05 Only
True RMS AC PCA Removal Option -09 Only
Main PCA Removal
 Maintenance
 Front Panel Disassembly
Reassembly Procedure
 Reassembly Procedure
 Front Panel Disassembly
 Removing the Display Window
 Troubleshooting
Internal Fuse Replacement
Initial Troubleshooting Procedure
 Troubleshooting
 16. Overall State Table
 T6-162.wmf
 17. Circuitry Tested by the Analog Self-Tests
 Diagnostic Self-Tests
 Test Number
Self-Test Descriptions
Test Point Voltage
 Maintenance
 8842A
 IN-GUARD Microcomputer System
Digital Controller Troubleshooting
 In-Guard Microcomputer
 Address Latch U219
 Display System
Calibration Memory U220
 Display Control U212
 To-8 Strobe Decoder U213
 Analog Control Signals
 Device REF. DES
Evaluating Static Signals
 21. Analog Control Logic States
 DC Scaling Troubleshooting
Evaluating Dynamic Signals
 Supply Voltage
PIN or Device
 Ohms Current Source Troubleshooting
Track/Hold Troubleshooting
 13. Typical Output Waveforms for Track/Hold Circuit TP103
 Precision Voltage Reference Troubleshooting
 14. Output of A/D Amplifier TP101
66. A/D Converter Troubleshooting
 15. Waveforms at U101-24 and U101-25
 For fire protection, use exact fuse replacement only
Power Supply Troubleshooting
 17. Waveforms at TP102 for Several Inputs on 2V DV Range
 Minimum Maximum
Test Point
 Service Position
IEEE-488 Interface Troubleshooting Option
Diagnostic Program
 Switches Configuration
Troubleshooting
 Port BIT
True RMS AC Troubleshooting Option
 Defective Ranges
Major Problems
Defective Stage
 Voltage AT TP801
Input Voltage
Voltage AT TP802
 More Obscure Problems
 Guard Crossing Troubleshooting
Internal Cleaning
Cleaning Printed Circuit Assemblies
 21. Guard Crossing Test Waveforms
Cleaning After Soldering
 8842A
 List of Replaceable Parts
 8842A
 Manual Status Information
HOW to Obtain Parts
 Newer Instruments
Service Centers
 REF of Option no
Assembly Fluke Part no
Revision Level
 F7-011.wmf
 F7-012.wmf
 F7-013.wmf
 F7-014.wmf
 A1 Main PCA
 CABLE, Display HEADER,1 ROW,.156CTR,6 PIN
 8842A
 F7-03.wmf
 A2 Display PCA
 F7-03.wmf
 Supply Codes for Manufacturers
 Supply2.wmf
 Service Centers
 Service2.wmf
 8842A
 Options and Accessories
 8842A
 Description
Model
Number Option
 Accessories
 Current Probes Y8100, Y8101, 80i-400
Current Shunt 80J-10
High Voltage Probes 80K-6 and 80K-40
 8842A
 Option -05 IEEE-488 Interface
 805-2
 External Controls
 Programming Instructions
Maintenance
List of Replaceable Parts
 List of Replaceable Parts
 805-6
 805-7
 805-8
 Option -09 True RMS AC
 809-2
 Option -09 True RMS AC
 Operating Instructions
 809-5
 Option -09 True RMS AC PCA
 809-7
 809-8
 Schematic Diagrams
 8842A
 Schematic Diagrams
 F9-012.wmf
 Main PCA, A/D Converter
 F9-022.wmf
 Main PCA, Ohms Current Source
 F9-032.wmf
 Main PCA, Digital
 F9-042.wmf
 Main PCA, Power Supply
 F9-052.wmf
 Display PCA
 F9-062.wmf
 F9-071.wmf
 F9-072.wmf
 IEEE-488 Interface PCA, Option
 IEEE-488 Interface PCA, Option -08