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®
Advanced Test Equipment Rentals
E stablished 1981 www.atecorp.com 800-404-ATEC (2832)
®
45
Dual Display Multimeter
Service Manual
For IEC 1010 Meters Only
PN 609203
March 1999 Rev.1, 1/04
© 1999-2004 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies.
LIMITED WARRANTY & LIMITATION OF LIABILITY
Each Fluke product is warranted to be free from defects in material and workmanship under
normal use and service. The warranty period is one year and begins on the date of shipment.
Parts, product repairs and services are warranted for 90 days. This warranty extends only to the
original buyer or end-user customer of a Fluke authorized reseller, and does not apply to fuses,
disposable batteries or to any product which, in Fluke's opinion, has been misused, altered,
neglected or damaged by accident or abnormal conditions of operation or handling. Fluke
warrants that software will operate substantially in accordance with its functional specifications for
90 days and that it has been properly recorded on non-defective media. Fluke does not warrant
that software will be error free or operate without interruption.
Fluke authorized resellers shall extend this warranty on new and unused products to end-user
customers only but have no authority to extend a greater or different warranty on behalf of Fluke.
Warranty support is available if product is purchased through a Fluke authorized sales outlet or
Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for
importation costs of repair/replacement parts when product purchased in one country is submitted
for repair in another country.
Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, free of
charge repair, or replacement of a defective product which is returned to a Fluke authorized
service center within the warranty period.
To obtain warranty service, contact your nearest Fluke authorized service center or send the
product, with a description of the difficulty, postage and insurance prepaid (FOB Destination), to
the nearest Fluke authorized service center. Fluke assumes no risk for damage in transit.
Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB
Destination). If Fluke determines that the failure was caused by misuse, alteration, accident or
abnormal condition of operation or handling, Fluke will provide an estimate of repair costs and
obtain authorization before commencing the work. Following repair, the product will be returned to
the Buyer transportation prepaid and the Buyer will be billed for the repair and return
transportation charges (FOB Shipping Point).
THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE
FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES,
INCLUDING LOSS OF DATA, WHETHER ARISING FROM BREACH OF WARRANTY OR BASED ON
CONTRACT, TORT, RELIANCE OR ANY OTHER THEORY.
Since some countries or states do not allow limitation of the term of an implied warranty, or
exclusion or limitation of incidental or consequential damages, the limitations and exclusions of
this warranty may not apply to every buyer. If any provision of this Warranty is held invalid or
unenforceable by a court of competent jurisdiction, such holding will not affect the validity or
enforceability of any other provision.
To locate an authorized service center, visit us on the World Wide Web: www.fluke.com
or call Fluke using the phone numbers listed below:
USA and Canada: 1-888-99-FLUKE (1-888-993-5853)
Europe: +31 402-675-200
Japan: +81-3-3434-0181
Singapore: +65-738-5655
Anywhere in the world: +1-425-446-5500
Fluke Corporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett, WA 98206-9090 5602 BD Eindhoven
U.S.A. The Netherlands
5/94
Table of Contents
Chapter Title Page
1 Introduction and Specifications ........................................................ 1-1
1-1. Introduction........................................................................................... 1-3
1-2. Operating Instructions .......................................................................... 1-3
1-3. Options and Accessories....................................................................... 1-3
1-4. Organization of the Service Manual ..................................................... 1-4
1-5. Conventions .......................................................................................... 1-5
1-6. Specifications........................................................................................ 1-6
2 Theory of Operation ........................................................................... 2-1
2-1. Introduction........................................................................................... 2-3
2-2. Functional Block Description ............................................................... 2-3
2-3. Power Supply.................................................................................... 2-3
2-4. Analog Measurement Processor ....................................................... 2-3
2-5. Input Protection Circuit .................................................................... 2-3
2-6. Input Signal Conditioning ................................................................ 2-3
2-7. Analog-to-Digital (A/D) Converter .................................................. 2-3
2-8. Serial Communication (Guard Crossing) ......................................... 2-3
2-9. Digital Kernel ................................................................................... 2-5
2-10. Display Assembly............................................................................. 2-5
2-11. IEEE-488 Interface Option (-05) ...................................................... 2-5
2-12. Battery Pack Option (-01) ................................................................ 2-5
2-13. Detailed Circuit Description................................................................. 2-5
2-14. Power Supply Circuit Description.................................................... 2-5
2-15. Raw DC Supply............................................................................ 2-6
2-16. 5-Volt Switching Supply.............................................................. 2-6
2-17. Inverter ......................................................................................... 2-7
2-18. Analog Measurement Processor ....................................................... 2-7
2-19. Input Protection ................................................................................ 2-10
2-20. Input Signal Conditioning ................................................................ 2-10
2-21. Relays........................................................................................... 2-11
2-22. DC Volts ...................................................................................... 2-12
2-23. Ohms ............................................................................................ 2-12
2-24. 100 M and 300 M Ranges...................................................... 2-14
2-25. AC Volts ...................................................................................... 2-14
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Service Manual
2-26. DCmA .......................................................................................... 2-15
2-27. ACmA .......................................................................................... 2-15
2-28. Amps ............................................................................................ 2-15
2-29. Diode/Continuity Test.................................................................. 2-15
2-30. Frequency..................................................................................... 2-15
2-31. Active Filter...................................................................................... 2-16
2-32. A/D Converter .................................................................................. 2-17
2-33. Serial Communication (Guard Crossing) ......................................... 2-18
2-34. Digital Kernel ................................................................................... 2-18
2-35. RS-232 Interface .......................................................................... 2-19
2-36. Microprocessor ............................................................................ 2-19
2-37. EEROM........................................................................................ 2-19
2-38. RAM............................................................................................. 2-20
2-39. ROM............................................................................................. 2-20
2-40. IEEE-488 Option Connections..................................................... 2-20
2-41. Display Assembly............................................................................. 2-20
2-42. Main Assembly Connector........................................................... 2-20
2-43. Front Panel Switches.................................................................... 2-20
2-44. Display ......................................................................................... 2-21
2-45. Beeper Drive Circuit .................................................................... 2-21
2-46. Watchdog Timer and Reset Circuit.............................................. 2-21
2-47. Display Controller with FIP......................................................... 2-22
3 General Maintenance ......................................................................... 3-1
3-1. Introduction........................................................................................... 3-3
3-2. Warranty Repairs and Shipping Information........................................ 3-3
3-3. General Maintenance Information........................................................ 3-3
3-4. Required Equipment......................................................................... 3-3
3-5. Power Requirements......................................................................... 3-3
3-6. Static Safe Handling......................................................................... 3-3
3-7. Cleaning................................................................................................ 3-4
3-8. Fuse Test and Replacement .................................................................. 3-4
3-9. Line Fuse .......................................................................................... 3-4
3-10. Current Input Fuses .......................................................................... 3-4
3-11. Testing Current Input Fuses......................................................... 3-4
3-12. Replacing the 500 mA and 440 mA Input Fuses (F1 and F5)...... 3-5
3-13. Replacing the 10 A Input Jack Fuse (F2)..................................... 3-6
3-14. Disassembly Procedures ....................................................................... 3-7
3-15. Remove the Meter Case.................................................................... 3-7
3-16. Remove Handle and Mounting Brackets.......................................... 3-7
3-17. Remove the Front Panel Assembly .................................................. 3-8
3-18. Remove the Display PCA................................................................. 3-8
3-19. Remove the IEEE-488 Option .......................................................... 3-9
3-20. Remove the Main PCA..................................................................... 3-9
3-21. Remove the Analog Measurement Processor Shields ...................... 3-9
3-22. Remove the Rms PCA...................................................................... 3-10
3-23. Remove the Battery Option .............................................................. 3-10
3-24. Disconnect Miscellaneous Chassis Components ............................. 3-10
3-25. Assembly Procedures............................................................................ 3-10
3-26. Install Miscellaneous Chassis Components ..................................... 3-10
3-27. Install the Battery Option ................................................................. 3-11
3-28. Install the Rms PCA ......................................................................... 3-11
3-29. Install the Analog Measurement Processor Shields ......................... 3-11
3-30. Install the Main PCA........................................................................ 3-11
ii
Contents (continued)
3-31. Install the IEEE-488 Option ............................................................. 3-12
3-32. Assemble the Front Panel Assembly................................................ 3-12
3-33. Install the Front Panel Assembly...................................................... 3-15
3-34. Install the Handle and Mounting Brackets ....................................... 3-15
3-35. Install the Meter Case....................................................................... 3-15
4 Performance Testing and Calibration ............................................... 4-1
4-1. Introduction........................................................................................... 4-3
4-2. Required Equipment ............................................................................. 4-3
4-3. Performance Tests ................................................................................ 4-4
4-4. Front Panel Calibration......................................................................... 4-7
4-5. Introduction ...................................................................................... 4-7
4-6. Entering Calibration Mode............................................................... 4-8
4-7. Exiting Calibration Mode................................................................. 4-9
4-8. DC Volts Calibration (Front Panel) ................................................. 4-9
4-9. AC Volts Calibration (Front Panel) ................................................. 4-9
4-10. DC and AC Milliamp Calibration (Front Panel) .............................. 4-9
4-11. DC and AC Amps Calibration (Front Panel) ................................... 4-11
4-12. Ohms Calibration (Front Panel) ....................................................... 4-11
4-13. Alternate Ohms Calibration (Front Panel) ....................................... 4-13
4-14. Continuity/Hysteresis Threshold Calibration (Front Panel) ............ 4-13
4-15. Frequency Calibration (Front Panel)................................................ 4-13
4-16. C2 Adjustment Procedure ................................................................ 4-13
4-17. Editing the Prompt for Different Calibration Points ........................ 4-14
4-18. Calibration Using the Computer Interface............................................ 4-15
4-19. Setup................................................................................................. 4-15
4-20. RS-232 Interface .......................................................................... 4-15
4-21. IEEE-488 Interface....................................................................... 4-16
4-22. The Calibration Procedure ............................................................... 4-18
4-23. DC Volts Calibration (Computer Interface)..................................... 4-19
4-24. AC Volts Calibration (Computer Interface)..................................... 4-19
4-25. DC and AC Milliamps Calibration (Computer Interface)................ 4-19
4-26. DC and AC Amps Calibration (Computer Interface)....................... 4-19
4-27. Ohms Calibration (Computer Interface)........................................... 4-19
4-28. Continuity/Hysteresis Threshold Calibration (Computer Interface) 4-20
4-29. Frequency Calibration (Computer Interface) ................................... 4-20
4-30. Concluding Calibration Using the Computer Interface.................... 4-20
4-31. Alternate Ohms Calibration (Computer Interface)........................... 4-20
5 Diagnostic Testing and Troubleshooting ......................................... 5-1
5-1. Introduction........................................................................................... 5-3
5-2. Servicing Surface-Mount Assemblies .................................................. 5-3
5-3. Error Codes ........................................................................................... 5-4
5-4. General Troubleshooting Procedures ................................................... 5-10
5-5. Power Supply Troubleshooting ........................................................ 5-10
5-6. Raw DC Supply............................................................................ 5-10
5-7. 5-Volt Switching Supply.............................................................. 5-11
5-8. Inverter ......................................................................................... 5-12
5-9. Analog Troubleshooting................................................................... 5-13
5-10. Uart Test....................................................................................... 5-13
5-11. DC Volts Troubleshooting........................................................... 5-14
5-12. AC Volts Troubleshooting........................................................... 5-14
5-13. Ohms Troubleshooting................................................................. 5-14
5-14. Digital Troubleshooting........................................................................ 5-15
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Service Manual
5-15. Display Assembly Troubleshooting...................................................... 5-17
5-16. Calibration Failures .............................................................................. 5-19
5-17. Introduction ...................................................................................... 5-19
5-18. Calibration-Related Components ..................................................... 5-20
5-19. Calibration Interrelationships........................................................... 5-21
5-20. Retrieving Calibration Constants ..................................................... 5-21
5-21. Replacing the EEROM A1U5 .......................................................... 5-21
6 List of Replaceable Parts................................................................... 6-1
6-1. Introduction........................................................................................... 6-3
6-2. How to Obtain Parts.............................................................................. 6-3
6-3. How to Contact Fluke ........................................................................... 6-4
6-4. Manual Status Information ................................................................... 6-4
6-5. Newer Instruments ................................................................................ 6-4
6-6. Parts ...................................................................................................... 6-4
7 Option -01 Battery Pack ..................................................................... 7-1
7-1. Introduction........................................................................................... 7-3
7-2. Specifications........................................................................................ 7-3
7-3. Theory of Operation ............................................................................. 7-3
7-4. Functional Block Description........................................................... 7-3
7-5. Switching Power Supply.............................................................. 7-5
7-6. Cycle/Float Charge Rate Switch .................................................. 7-5
7-7. Low Battery Indicator Detector ................................................... 7-5
7-8. Low Battery Disconnect............................................................... 7-5
7-9. Constant Voltage Trickle Charger ............................................... 7-6
7-10. Other Circuits............................................................................... 7-6
7-11. General Maintenance ............................................................................ 7-6
7-12. Removal............................................................................................ 7-6
7-13. Installation ........................................................................................ 7-7
7-14. Performance Testing............................................................................. 7-9
7-15. General Operability .......................................................................... 7-9
7-16. Low Battery Indicator Detector and Low Battery Disconnect Test. 7-10
7-17. Cycle/Float Charge Rate Switch Test .............................................. 7-10
7-18. Calibration ............................................................................................ 7-12
7-19. Troubleshooting.................................................................................... 7-13
7-20. Additional Tests.................................................................................... 7-14
7-21. Schematic Diagram............................................................................... 7-14
7-22. List of Replaceable Parts ...................................................................... 7-14
8 Option -05 IEEE-488 Interface............................................................ 8-1
8-1. Introduction........................................................................................... 8-3
8-2. Theory of Operation ............................................................................. 8-3
8-3. Functional Block Description........................................................... 8-3
8-4. Detailed Circuit Description............................................................. 8-3
8-5. Main Assembly Connectors ......................................................... 8-3
8-6. Address Decoding Circuit............................................................ 8-3
8-7. Isolation Circuits .......................................................................... 8-4
8-8. IEEE-488 Controller .................................................................... 8-4
8-9. IEEE-488 Transceivers/Connector............................................... 8-5
8-10. General Maintenance ............................................................................ 8-8
8-11. Removing the IEEE-488 Interface Option ....................................... 8-8
8-12. Installing the IEEE-488 Interface Option......................................... 8-9
iv
Contents (continued)
8-13. Performance Testing............................................................................. 8-9
8-14. Troubleshooting.................................................................................... 8-10
8-15. Power-up Problems .......................................................................... 8-10
8-16. Communication Problems ................................................................ 8-10
8-17. Failure to Select IEEE-488 Interface Option ............................... 8-10
8-18. Failure to Handshake on IEEE-488 Bus ...................................... 8-11
8-19. Failure to Enter Remote ............................................................... 8-11
8-20. Failure to Receive Multiple Character Commands...................... 8-12
8-21. Failure to Transmit Query Responses.......................................... 8-12
8-22. Failure to Generate an End or Identify (EOI) .............................. 8-12
8-23. Failure to Generate a Service Request (SRQ).............................. 8-12
8-24. Schematic Diagram............................................................................... 8-12
8-25. List of Replaceable Parts ...................................................................... 8-12
9 Schematic Diagrams .......................................................................... 9-1
Index
v
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Service Manual
vi
List of Tables
Table Title Page
1-1. Accessories............................................................................................................. 1-4
2-1. Analog Measurement Processor Pin Name Description ........................................ 2-9
2-2. Relay Operation ..................................................................................................... 2-11
2-3. Reference Resistance ............................................................................................. 2-13
2-4. AC Volts Input Signal Dividers ............................................................................. 2-14
2-5. Front Panel Switch Scanning ................................................................................. 2-21
2-6. Display Initialization Modes .................................................................................. 2-23
3-1. Fuses....................................................................................................................... 3-6
4-1. Recommended Test Equipment ............................................................................. 4-3
4-2. Performance Tests for Volts, Diode Test, Ohms, and Frequency Functions......... 4-5
4-3. Performance Tests for mA Current Functions ....................................................... 4-7
4-4. Performance Tests for Current Functions .............................................................. 4-7
4-5. Front Panel Calibration .......................................................................................... 4-10
4-6. Specifications Increase with Different Calibration Points..................................... 4-15
4-7. Calibration Using the Computer Interface ............................................................. 4-17
4-8. Calibration Mode Computer Interface Commands ................................................ 4-21
4-9. EEROM Calibration Constants .............................................................................. 4-22
5-1. Error Codes ............................................................................................................ 5-5
5-2. Power Supplies....................................................................................................... 5-11
5-3. DC Volts Troubleshooting ..................................................................................... 5-14
5-4. AC Volts Troubleshooting ..................................................................................... 5-15
5-5. Display Initialization.............................................................................................. 5-18
5-6. Calibration Steps and Related Components........................................................... 5-22
5-7. Components Unique to Calibration Steps .............................................................. 5-23
5-8. Calibration Hierarchy............................................................................................. 5-24
5-9. Calibration Constants............................................................................................. 5-24
6-1. Manual Status Information..................................................................................... 6-4
6-2. Final Assembly....................................................................................................... 6-5
6-3. A1 Main PCA......................................................................................................... 6-8
6-4. A1A1 True Rms PCA ............................................................................................ 6-12
6-5. A2 Display PCA..................................................................................................... 6-13
7-1. Option -01 Battery Pack Final Assembly............................................................... 7-15
7-2. A4 Battery Pack PCA............................................................................................. 7-16
8-1. IEEE-488 Transceiver Control............................................................................... 8-6
8-2. Option -05 IEEE - 488 Interface Final Assembly .................................................. 8-13
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Service Manual
8-3. A5 IEEE-488 Interface PCA .................................................................................. 8-14
viii
List of Figures
Figure Title Page
2-1. Overall Functional Block Diagram ........................................................................ 2-4
2-2. Analog Simplified Schematic Diagram.................................................................. 2-8
2-3. DC Volts 300 V Range Simplified Schematic....................................................... 2-12
2-4. Ohms Simplified Schematic................................................................................... 2-13
2-5. AC Buffer Simplified Schematic ........................................................................... 2-14
2-6. DC mA and Amps Simplified Schematic............................................................... 2-16
2-7. Active Filter Simplified Schematic........................................................................ 2-17
2-8. A/D Converter Simplified Schematic .................................................................... 2-18
2-9. Command Byte Transfer Waveforms .................................................................... 2-23
2-10. Grid Control Signal Timing ................................................................................... 2-24
2-11. Grid-Anode Timing Relationships ......................................................................... 2-24
3-1. Replacing the Line Fuse (F3)................................................................................. 3-5
3-2. Replacing the External 100 mA Input Fuse (F1) ................................................... 3-6
3-3. Removing the Case................................................................................................. 3-7
3-4. Removing the Handle and Handle Mounting Brackets.......................................... 3-8
3-5. Assembly Details ................................................................................................... 3-13
4-1. Four Wire Configuration........................................................................................ 4-12
4-2. C2 Location............................................................................................................ 4-14
5-1. Test Point Locator.................................................................................................. 5-6
5-2. Volt Switching Supply ........................................................................................... 5-12
5-3. Main Processor Timing.......................................................................................... 5-16
5-4. Display Controller to Microprocessor Signals....................................................... 5-17
5-5. Primary Display...................................................................................................... 5-18
5-6. Secondary Display ................................................................................................. 5-18
6-1. Final Assembly....................................................................................................... 6-6
6-2. A1 Main PCA......................................................................................................... 6-11
6-3. A1A1 True Rms PCA ............................................................................................ 6-12
6-4. A2 Display PCA..................................................................................................... 6-14
7-1. Battery Pack Option Functional Block Diagram.................................................... 7-4
7-2. Removing the Case................................................................................................. 7-7
7-3. Installing the Battery Kit........................................................................................ 7-8
7-4. Battery Pack Option Connecting Cable ................................................................. 7-9
7-5. Cycle/Float Charge Rate Switch Test .................................................................... 7-11
7-6. Unplugging the Battery Pack Connectors .............................................................. 7-13
7-7. Test Points and Adjustments.................................................................................. 7-14
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Service Manual
7-8. Option-01 Battery Pack Final Assembly................................................................ 7-15
7-9. A4 Battery Pack PCA............................................................................................. 7-18
8-1. Disassembly ........................................................................................................... 8-6
8-2. IEEE-488 Interface Connector ............................................................................... 8-7
8-3. IEEE-488 Module Assembly.................................................................................. 8-8
8-4. IEEE-488 Interface Performance Test ................................................................... 8-10
8-5. Option -05 IEEE-488 Interface Final Assembly .................................................... 8-13
8-6. A5 IEEE-488 Interface PCA .................................................................................. 8-15
9-1. A1 Main PCA......................................................................................................... 9-2
9-1. A1 Main PCA......................................................................................................... 9-2
9-2. A2 Display PCA..................................................................................................... 9-8
9-3. A1A1 True Rms PCA ............................................................................................ 9-10
9-4. A4 Battery PCA ..................................................................................................... 9-12
9-5. A5 IEEE-488 Interface PCA .................................................................................. 9-14
x
Chapter 1
Introduction and Specifications
Title Page
1-1. Introduction............................................................................................. 1-3
1-2. Operating Instructions ............................................................................ 1-3
1-3. Options and Accessories......................................................................... 1-3
1-4. Organization of the Service Manual ....................................................... 1-4
1-5. Conventions ............................................................................................ 1-5
1-6. Specifications.......................................................................................... 1-6
1-1
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Service Manual
1-2
Introduction and Specifications
Introduction 1
1-1. Introduction
The Fluke 45 Dual Display Multimeter (also referred to as "the meter") is a 4-1/2-digit
(30,000-count) meter with a 5-digit (100,000-count) high resolution mode designed for
bench-top, field service, and system applications. The meter uses a dual vacuum-
fluorescent display, allowing for two types of readings from a single input. Primary and
secondary displays show the user-defined readings side by side. Even though the
readings are made sequentially, the displays show both readings at all times for ease of
comparison.
Some features provided by the meter are:
· Computer interface operation via the RS-232 interface (included) or the IEEE-488
interface (optional). The meter is fully programmable for use on the IEEE Standard
488.1 (1987). The meter is also designed in compliance with supplemental standard
IEEE-488.2 (1987).
· True rms ac
· (AC + DC) rms, calculated
· Frequency measurements to greater than 1 MHz.
· 1 µV sensitivity in volts dc
· Decibels with variable reference impedance and audio power measurement
capability.
· A compare mode to determine if a measurement is within, above, or below a
designated range.
· 100,000, 30,000, and 3,000 selectable count resolution, with reading speeds of 2.5, 5,
and 20 readings per second (rps), respectively.
· Built-in self-tests with closed-case calibration (no internal adjustments).
1-2. Operating Instructions
Full operating instructions are provided in the Fluke 45 Users Manual. Reference to
these instructions may be necessary during some of the maintenance and repair
procedures presented in this Service Manual. For quick references, an operating
instruction summary is presented on the inside of the front cover of the Service Manual.
For more detailed information, refer to the Users Manual.
1-3. Options and Accessories
Three options are available. These options can be installed either at the factory or in the
field. The following discussions pertain to the field-installable option kits:
· The Battery Kit (Option -01K) consists of a rechargeable, 8 V, lead-acid battery,
with battery bracket and charger assembly. The battery has a typical operating time
of eight hours and is fully operable at ambient temperatures between 0 and 50ºC.
· The IEEE-488 Interface Kit (Option -05K) consists of a printed circuit assembly,
connecting cables, and mounting hardware. This option provides full
programmability, external trigger input, and automated calibration. The IEEE-488
computer interface command set is identical to the RS-232 interface commands
wherever possible.
· Option -15K combines Options -01K and -05K as a single kit.
1-3
45
Service Manual
The Fluke 45 Dual Display Multimeter can be mounted in a standard 19-inch rack panel
on either the right-hand or left-hand side using the Fluke M00-200-634 Rack Mount Kit.
Accessories for the Fluke 45 are listed in Table 1-1.
Table 1-1. Accessories
Model Description
C40 Soft carrying case. Provides padded protection for the meter. Includes a pocket for the
manual and pouch for the test leads and line cord.
M00-200- Rackmount Kit. Allows meter to be mounted on either the right or left side of a standard
634 19-inch rack.
RS40 RS-232 terminal interface cable. Connects other Fluke 45 to any terminal or printer with
properly configured DTE connector (DB-25, female pins), including an IBM PC®, IBM
PC/XT® or IBM PS/2 (models 25, 30, 50, P60, 70, and 80).
RS41 RS-232 modem cable. Connects the Fluke 45 to a modem.
S45 QuickStartTM, a PC software package, simplifies operation of the Fluke 45 when using
the RS-232 computer interface. Readings are recorded in files that can be accessed by
Lotus 1-2-3®, dBase III® and other graphics packages.
Y8021 Shielded IEEE-488 one-meter (39.4 inches) cable, with plug and jack at each end.
Y8022 Shielded IEEE-488 two-meter (78.8 inches) cable, with plug and jack at each end.
Y8023 Shielded IEEE-488 four-meter (13 feet) cable, with plug and jack at each end.
QuickStart 45 is a trademark of Fluke Corporation.
Lotus is a registered trademark of Lotus Development Co.
dBase III is a registered trademark of Ashton-Tate.
IBM PC and IBM PC/XT are registered trademarks of International Business Machines.
1-4. Organization of the Service Manual
This manual focuses on component-level repair of the Fluke 45 Dual Display
Multimeter. To that end, manual chapters are often interdependent; effective
troubleshooting may require not only reference to the troubleshooting procedures in
Chapter 5, but also some understanding of the detailed Theory of Operation in Chapter 2
and some tracing of circuit operation in the Schematic Diagrams presented in Chapter 9.
Often, scanning the table of contents will yield an appropriate place to start using the
manual. A comprehensive table of contents is presented at the front of the manual; local
tables of contents are also presented at the beginning of each chapter for ease of
reference. If you know the topic name, the index at the end of the manual is probably a
good place to start.
The following chapter descriptions serve to introduce the manual:
Chapter 1. Introduction and Specifications
Introduces the Fluke 45 Dual Display Multimeter, describing its features, options, and
accessories. This chapter also discusses use of the Service Manual and the various
conventions used in describing the meter's circuitry. Finally, a complete set of
specifications is presented.
1-4
Introduction and Specifications
Conventions 1
Chapter 2. Theory of Operation
This chapter first categorizes meter circuitry into functional blocks, with a description of
each block's role in overall operation. A detailed circuit description is then given for
each block. These descriptions explore operation to the component level and fully
support troubleshooting procedures defined in Chapter 5.
Chapter 3. General Maintenance
Provides maintenance information covering handling, cleaning, and fuse replacement.
Access and reassembly procedures are also explained in this chapter.
Chapter 4. Performance Testing and Calibration
This chapter provides performance verification procedures that are tied to the
specifications presented in Chapter 1. To maintain these specifications, a full calibration
procedure is also presented.
Chapter 5. Diagnostic Testing and Troubleshooting
The troubleshooting procedures presented in this chapter rely closely on both the Theory
of Operation presented in Chapter 2 and the Schematic Diagrams shown in Chapter 9.
Chapter 3 provides access information.
Chapter 6. List of Replaceable Parts
Includes parts lists for all standard assemblies. Information on how and where to order
parts is also provided.
Chapter 7. Option -01 Battery Pack
Each option is allocated a separate chapter: 7 for the Battery Pack Option -01 and 8 for
the IEEE-488 Interface Option -05. Option -15 incorporates both Options -01 and -05.
Chapter 7 includes the full range of Service Manual topics (specifications, theory of
operation, maintenance, list of replaceable parts, etc.) for the Battery Pack option.
Schematic diagrams for the options are found in Chapter 9.
Chapter 8. Option -05 IEEE-488 Interface
Includes the full range of Service Manual topics (specifications, theory of operation,
maintenance, list of replaceable parts, etc.) for the IEEE-488 Interface option. Schematic
diagrams for the options are found in Chapter 9.
Chapter 9. Schematic Diagrams
Includes schematic diagrams for all standard and optional assemblies. A list of
mnemonic definitions is also included to aid in identifying signal name abbreviations.
1-5. Conventions
Throughout the manual set, certain notational conventions are used. A summary of these
conventions follows:
· Instrument Reference
The Fluke 45 Dual Display Multimeter is usually called the "meter."
· Printed Circuit Assembly
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Service Manual
The term "pca" is used to represent a printed circuit assembly and its
attached parts.
· Signal Logic Polarity
On schematic diagrams, a signal name followed by a "*" is active (or
asserted) low. Signals not so marked are active high.
· Circuit Nodes
Individual pins or connections on a component are specified with a dash (-)
following the component reference designator. For example, pin 19 of U30
would be U30-19.
· User Notation
For front panel operation,
XXX An uppercase word or symbol without parentheses indicates a button
to be pressed by the user. Buttons can be pressed in four ways:
1. Press a single button to select a function or operation.
2. Press a combination of buttons, one after the other.
3. Press and hold down a button, then press another button.
4. Press multiple buttons simultaneously.
For computer interface operation,
XXX An uppercase word without parentheses identifies a command
by name.
Angle brackets around all uppercase letters mean press
the key.
(xxx) When associated with a keyword, a lowercase word in
parentheses indicates an input required by the user.
1-6. Specifications
The following contains the specifications for the Fluke 45 Dual Display Multimeter.
These specifications assume:
· A 1-year calibration cycle
· An operating temperature of 18 to 28ºC
· Relative humidity not exceeding 90% (non-condensing)
Accuracy is expressed as ±(percentage of reading + counts).
Reading Rates and Display Counts
Rate Readings per Second Full Range Display Counts
Slow 2.5 99,999*
Medium 5 30,000
Fast 20 3,000
* Ohms full range will typically be 98,000 counts
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Introduction and Specifications
Specifications 1
Response Times
Refer to Chapter 4 of the Users Manual for detailed information.
DC Voltage
Resolution Accuracy
Range Slow Medium Fast (6 months) (1 year)
300 mV - 10 µV 100 µV 0.02% + 2 0.025%+2
3V - 100 µV 1 mV 0.02% + 2 0.025% +2
30 V - 1 mV 10 mV 0.02% + 2 0.025%+2
300 V -- 10 mV 100 mV 0.02% + 2 0.025% +2
1000 V - 100 mV 1V 0.02% + 2 0.025%+2
100 mV 1 µV - - 0.02% + 6 0.025%+6
1000 mV 10 µV - - 0.02% + 6 0.025% +6
10 V 100 µV - - 0.02% + 6 0.025%+6
100 V 1 mV - - 0.02% + 6 0.025% +6
1000 V 10 mV - - 0.02% + 6 0.025%+6
Input Impedance
10 M in parallel with <100 pF
Note
In the dual display mode, when the volts ac and volts dc functions are
selected, the 10 M dc input divider is in parallel with the 1 M ac
divider.
Normal Mode Rejection Ratio
>80 dB at 50 or 60 Hz, slow and medium rates
>54 dB for frequencies between 50-440 Hz, slow and medium rates
>60 dB at 50 Hz, fast rate (Note: Fast rate has no filtering)
Maximum Allowable AC Voltage While Measuring DC Voltage
Peak Normal Mode Signal
Range Max Allowable Peak AC Voltage NMRR* >80dB** NMRR >60 dB**
300 mV 100 mV 20 V 15 V 15 V
3V 1000 mV 20 V 15 V 15 V
30 V 10 V 1000 V 50 V 300 V
300 V 100 V 1000 V 50 V 300 V
1000 V 1000 V 1000 V 200 V 1000 V
* NMRR is the Normal Mode Rejection Ratio
** Normal Mode Rejection Ratio at 50 or 60 Hz ± 0.1%
Common Mode Rejection Ratio
>90 dB at dc, 50 or 60 Hz, (1 k unbalanced, medium and slow rates)
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Maximum Functional Input
1000 V dc or peak ac on any range
True Rms AC Voltage, AC-Coupled
Range Resolution
Slow Medium Fast
300 mV - 10 µV 100 µV
3V - 100 µV 1 mV
30 V - 1 mV 10 mV
300 V - 10 mV 100 mV
750 V - 100 mV 1V
100 mV 1 µV - -
1000 mV 10 µV - -
10 V 100 µV - -
100 V 1 mV - -
750 V 10 mV - -
Accuracy
Max Input
Frequency Linear Accuracy dB Accuracy Power* at Upper
Freq
Slow Medium Fast Slow/Med Fast
20-50 Hz 1% + 100 1% + 10 7% + 2 0.15 0.72 2% + 10 750 V
50 Hz -10 kHz 0.2% + 100 0.2% + 10 0.5% + 0.08 0.17 0.4% + 10 750 V
2
10 - 20 kHz 0.5% + 100 0.5% + 10 0.5% + 0.11 0.17 1% + 10 750 V
2
20 - 50 kHz 2% + 200 2% + 20 2% + 3 0.29 0.34 4% + 20 400 V
50 - 100 kHz 5% + 500 5% + 50 5% + 6 0.70 0.78 10% + 50 200 V
* Error in power mode will not exceed twice the linear accuracy specification
Accuracy specifications apply within the following limits, based on reading rate:
Slow Reading Rate: Between 15,000 and 99,999 counts (full range)