User ManualTable of Contents8842A Instruction Manual1Table of Contents3List of Tables9List of Figures111. Introduction and Specifications15INTRODUCTION16THE 8842A DIGITAL MULTIMETER16OPTIONS AND ACCESSORIES16SPECIFICATIONS172. Operating Instructions26INTRODUCTION27INSTALLATION27Installing the Power-Line Fuse27Connecting to Line Power27Adjusting the Handle28Rack Mounting Kits28OPERATING FEATURES29Power-Up Features29Front and Rear Panel Features29Display Features33Error Messages33Overrange Indication35Diagnostic Self-Tests35Ranging35AUTORANGE35MANUAL RANGE36Triggering36CONTINUOUS TRIGGER MODE36EXTERNAL TRIGGER MODE36Reading Rates and Noise Rejection36Automatic Settling Time Delay37External Trigger Input (Option -05 Only)37Sample Complete Output (Option -05 Only)37MAKING MEASUREMENTS38Input Overload Protection Limits38Measuring Voltage and Resistance38Measuring Current38Current Fuse Protection38Offset Measurements39EXTERNAL CLEANING403. Remote Programming42INTRODUCTION44CAPABILITIES44BUS SET-UP PROCEDURE44AN OVERVIEW OF REMOTE OPERATION45A NOTE ABOUT EXAMPLES47DEVICE-DEPENDENT COMMAND SET47Bn (Offset Commands)50Cn (Calibration Commands)50Dn (Display Commands)50Fn (Function Commands)51Get Commands51G0 (Get Instrument Configuration)53G1 (Get SRQ Mask)53G2 (Get Calibration Prompt)53G3 (Get User-Defined Message)54G4 (Get Calibration Status)54G5 (Get IAB Status)55G6 (Get YW Status)55G7 (Get Error Status)55G8 (Get Instrument Identification)56N (Numeric Entry Command)56Put Commands56P0 (Put Instrument Configuration)56P1 (Put SRQ Mask)57P2 (Put Calibration Value)57P3 (Put User-Defined Message)58Rn (Range Commands)58Sn (Reading Rate Commands)58Tn (Trigger Mode Commands)59Wn (Terminator Commands)60X0 (Clear Error Register Command)60Yn (Suffix Commands)60Z0 (Self-Test Command)60(Device-Clear Command)61? (Single-Trigger Command)61INPUT SYNTAX61Definitions62Input Processing62Syntax Rules64OUTPUT DATA65Loading Output Data65Types of Output Data66Numeric Data and Error Messages66MEASUREMENT DATA66OVERRANGE INDICATION67ERROR MESSAGES67Status Data67SERVICE REQUESTS68INTERFACE MESSAGES70TALK-ONLY MODE71REMOTE CALIBRATION72TIMING CONSIDERATIONS72IMMEDIATE MODE COMMANDS72EXAMPLE PROGRAMS734. Measurement Tutorial92INTRODUCTION93DC VOLTAGE MEASUREMENT93Circuit Loading Error93Input Bias Current Error94RESISTANCE MEASUREMENT952-Wire Ohms95Correcting for Test Lead Resistance in 2-Wire Ohms964-Wire Ohms96Applications of the Ohms Functions98TESTING DIODES98TESTING ELECTROLYTIC CAPACITORS98A PRECISION CURRENT SOURCE99DC CURRENT MEASUREMENT99REDUCING THERMAL VOLTAGES100AC VOLTAGE AND CURRENT MEASUREMENT101True RMS Measurement101Waveform Comparison101Crest Factor103AC-Coupled AC Measurements103Combined AC and DC Measurements104Bandwidth104Zero-Input VAC Error104MAKING ACCURATE MEASUREMENTS ON THE 20 mV AND 20( RANGES105MAKING ACCURATE HIGH-RESISTANCE MEASUREMENTS1065. Theory of Operation108INTRODUCTION110OVERALL FUNCTIONAL DESCRIPTION110DETAILED CIRCUIT DESCRIPTION111DC SCALING111VDC Scaling113VDC Protection114mA DC Scaling114Analog Filter114TRACK/HOLD CIRCUIT115Track Configuration117Settling Configuration118Hold Configuration118Pre-Charge Configuration118PRECISION VOLTAGE REFERENCE118OHMS CURRENT SOURCE119OHMS PROTECTION120OHMS FUNCTIONS1202-Wire Ohms1204-Wire Ohms122A/D CONVERTER122Timing/Data Control124Precision DAC124A/D Amplifier125Bootstrap Supplies125DISPLAY125KEYBOARD126DIGITAL CONTROLLER126In-Guard Microcomputer128Function and Range Control130A/D Control and Computation130Calibration Correction130Keyboard/Display Control131Troubleshooting Modes131Guard-Crossing Communication131GUARD CROSSING131POWER SUPPLY132IEEE-488 INTERFACE (OPTION -05)133Out-Guard Microcomputer133Guard Crossing133Bus Interface Circuitry133Signal Conditioning134IEEE-488 Interface Power Supply134TRUE RMS AC (OPTION -09)134VAC Scaling134mA AC Scaling135Frequency Response Trimming135True RMS AC-to-DC Conversion135Static Awareness1366. Maintenance138INTRODUCTION140PERFORMANCE TEST141Diagnostic Self-Tests141DC Voltage Test142AC Voltage Test (Option -09 Only)144Resistance Test145DC Current Test146AC Current Test (Option -09 Only)147CALIBRATION147Basic Calibration Procedure148INITIAL PROCEDURE148A/D CALIBRATION149OFFSET AND GAIN CALIBRATION151HIGH-FREQUENCY AC CALIBRATION152Advanced Features and Special Considerations153STORING VARIABLE INPUTS153CALIBRATING INDIVIDUAL RANGES154VERIFYING CALIBRATION154ERASING CALIBRATION MEMORY155TOLERANCE CHECK155AC CALIBRATION AT OTHER FREQUENCIES156OPTIMIZING USE OF THE 5450A156Remote Calibration157TIMING CONSIDERATIONS160REMOTE ERASURE161DISASSEMBLY PROCEDURE162Case Removal163True RMS AC PCA Removal (Option -09 Only)167IEEE-488 Interface PCA Removal (Option -05 Only)167Main PCA Removal167Front Panel Disassembly169REASSEMBLY PROCEDURE169INTERNAL FUSE REPLACEMENT173EXTERNAL TRIGGER POLARITY SELECTION (Option -05 Only)173TROUBLESHOOTING173Initial Troubleshooting Procedure173Diagnostic Self-Tests178Self-Test Descriptions179Digital Controller Troubleshooting182DC Scaling Troubleshooting191Track/Hold Troubleshooting193Ohms Current Source Troubleshooting193Precision Voltage Reference Troubleshooting195A/D Converter Troubleshooting196Power Supply Troubleshooting198IEEE-488 Interface Troubleshooting (Option -05)201True RMS AC Troubleshooting (Option -09)203Guard Crossing Troubleshooting207INTERNAL CLEANING207Cleaning Printed Circuit Assemblies207Cleaning After Soldering2087. List of Replaceable Parts210INTRODUCTION212HOW TO OBTAIN PARTS212MANUAL STATUS INFORMATION212NEWER INSTRUMENTS213SERVICE CENTERS2138. Options and Accessories230INTRODUCTION232ACCESSORIES233Rack-Mount Kits (Y8834, Y8835 and Y8836)233Shielded IEEE-488 Interface Cables (Y8021, Y8022, and Y8023)233Replacement Test Leads (TL70A)233Deluxe Test Lead Kits (Y8134)233Slim-Flex Test Leads (Y8140)233Temperature Probes (80T-150U, and 80TK.)233RF Probes (85RF and 83RF)233Current Shunt (80J-10)234Current Probes (Y8100, Y8101, 80i-400 and 80i-600)234High Voltage Probes (80K-6 and 80K-40)234805. Option -05 IEEE-488 Interface236INTRODUCTION238CAPABILITIES238EXTERNAL CONTROLS238INSTALLATION238PROGRAMMING INSTRUCTIONS239MAINTENANCE239LIST OF REPLACEABLE PARTS239809. Option -09 True RMS AC244INTRODUCTION246INSTALLATION246OPERATING INSTRUCTIONS247MAINTENANCE247LIST OF REPLACEABLE PARTS2479. Schematic Diagrams252Size: 13.2 MBPages: 269Language: EnglishOpen manual