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Fluke 8508A Service Manual

Reference multimeter
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®
8508A
Reference Multimeter

Service Manual

September 2004
Rev. 1, 8/08
© 2004, 2008 Fluke Corporation, All rights reserved. Specifications are subject to change without notice
All product names are trademarks of their respective companies.

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Summary of Contents for Fluke 8508A

  • Page 1: Service Manual

    ® 8508A Reference Multimeter Service Manual September 2004 Rev. 1, 8/08 © 2004, 2008 Fluke Corporation, All rights reserved. Specifications are subject to change without notice All product names are trademarks of their respective companies.
  • Page 2 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 only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price.

  • Page 3: Table Of Contents

    Introduction and Specifications............1-1 Introduction......................1-3 Safety Considerations ..................1-3 Symbols ......................1-5 Service Information ................... 1-6 How to Contact fluke ..................1-6 Specifications..................... 1-6 General Specifications................... 1-7 Maximum Voltage and Current Inputs............1-8 DC and AC Voltage .................. 1-8 DC and AC Current...................
  • Page 4 8508A Service Manual Calibration and Verification..............3-1 Introduction......................3-3 Calibration Overview..................3-3 Calibration Interval and Performance ..............3-3 Calibration Points ....................3-3 Non-Nominal Values..................3-4 Enabling Access to Calibration Mode ............... 3-4 Calibration Menus....................3-4 Accessing the Calibration Menus and Calibration Mode ......3-4 Calibration Menu...................
  • Page 5 Self Test ......................4-13 Self-Test Errors ..................... 4-13 Fatal Errors ....................4-16 Execution Errors.................... 4-18 Device Dependant Errors ................4-19 List of Replaceable Parts..............5-1 Introduction......................5-3 How to Obtain Parts................... 5-3 How to Contact Fluke ..................5-3 Parts Lists......................5-4...
  • Page 6 8508A Service Manual...
  • Page 7 4-7. Serial Loop Mismatch Errors ................. 4-18 4-8. Execution Errors..................... 4-19 4-9. Device Dependent Errors ..................4-20 5-1. 8508A Final Assembly................... 5-4 5-2. 8508A Chassis Assembly..................5-6 5-2. Bezel (front panel) Assembly................. 5-7 5-4. A6Rear Input Assembly (optional) ................ 5-12...
  • Page 8 8508A Service Manual...
  • Page 9 List of Figures Figure Title Page 1-1. 8508A Dimentional Outline Drawing ..............1-6 2-1. 8508A Functional Block Diagram ................. 2-4 2-2. Power Supplies - Simplified Block Diagram ............2-7 3-1. Equipment Connections Required for Calibration ..........3-13 4-1. Internal Wiring and Cabling Diagram..............4-4 4-3.
  • Page 10 8508A Service Manual viii...

  • Page 11: Introduction And Specifications

    Page Introduction......................1-3 Safety Considerations ..................1-3 Symbols ......................1-5 Service Information ..................... 1-6 How to Contact fluke ................... 1-6 Specifications....................... 1-6 General Specifications..................1-7 Maximum Voltage and Current Inputs............1-8 DC and AC Voltage ..................1-8 DC and AC Current..................1-8 Resistance and Temperature ...............
  • Page 12 8508A Service Manual...

  • Page 13: Introduction

    Introduction and Specifications Introduction Introduction The Fluke 8508A Reference Multimeter (hereafter "the Multimeter") is designed for the most demanding measurement applications and provides extremely high measurement precision in both stand-alone and systems applications. This Service Manual provides the information necessary to maintain the Multimeter at a module (or board) level.
  • Page 14 8508A Service Manual XW Safety – Read First Warning: To avoid possible electric shock, personal injury, or death, read the following before using the Multimeter: ⇒ Use the Multimeter only as specified in this manual, or the protection provided by the Multimeter might be impaired.

  • Page 15: Symbols

    IEC 61010 Overvoltage (installation or AC (Alternating Current). measurement) Category . DC (Direct Current). Fuse. Do not dispose of this product as unsorted municipal waste. Go to Fluke’s website for AC or DC (Alternating or Direct Current) recycling information. < Recycle. Digital signal.

  • Page 16: Service Information

    8508A Service Manual Service Information In case of difficulty within the 1-year Warranty period, return the Multimeter to a Fluke Service Center for Warranty repair. For out of Warranty repair, contact a Fluke Service Center for a cost estimate. This service manual provides instructions for verification of performance, calibration, and maintenance.

  • Page 17: General Specifications

    Introduction and Specifications Specifications General Specifications Power Voltage 115 V Setting ............. 100 V to 120 V rms 10 % 230 V Setting ............. 200 V to 240 V rms 10 % Frequency ............... 47 Hz to 63 Hz Consumption............< 80 VA Dimensions Height..............

  • Page 18: Maximum Voltage And Current Inputs

    8508A Service Manual Maximum Voltage and Current Inputs Notes to maximum voltage and current input specifications Maximum DC input equal to maximum rms input. Maximum peak input is rms x 1.414 Specifications apply equally to front and rear input terminals except where noted below.

  • Page 19: Dc Voltage

    Introduction and Specifications Specifications DC Voltage [1] [2] [3] DC Voltage Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [15] Range Full Scale 24 hour 90 day 365 day 365 day 365 day TCal TCal ±1 °C TCal ±1 °C TCal ±1 °C TCal ±1 °C...

  • Page 20: Dc Current

    8508A Service Manual DC Current [1] [2] [3] DC Current Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [15] Range Full Scale 24 hour 90 day 365 day 365 day 365 day TCal ±1 °C TCal ±1 °C...

  • Page 21: Ac Voltage

    Introduction and Specifications Specifications AC Voltage [1] [2] [6] [7] AC Voltage Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [15] Range Full Scale Frequency (Hz) 24 hour 90 day 365 day 365 day 365 day TCal ±1 °C TCal ±1 °C TCal ±1 °C...
  • Page 22 8508A Service Manual [1] [2] AC Voltage (Secondary Specifications) Temperature Coefficient 5 °C - 15 °C Range Frequency (Hz) 15 °C - 30 °C 30 °C - 40 °C ± ppm Reading/°C 200 mV 1 - 10 10 - 40...

  • Page 23: Ac Current

    Introduction and Specifications Specifications AC Current [1] [2] [6] [9] AC Current Uncertainty Relative to Cal Stds Absolute Uncertainties Frequency ± (ppm Reading + ppm Range) [15] Range Full Scale (Hz) 24 hour 90 day 365 day 365 day 365 day TCal ±1 °C TCal ±1 °C TCal ±1 °C...
  • Page 24 8508A Service Manual [1] [2] [6] [9] AC Current (Secondary Specifications) Temperature Coefficient Input Impedance ( ) 5 °C - 15 °C Range Frequency (Hz) 15 °C - 30 °C 30 °C - 40 °C ± ppm Reading/°C Range Front...

  • Page 25: Resistance

    Introduction and Specifications Specifications Resistance [1] [2] [3] [9] Resistance Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [15] [10] Range Full Scale Mode 24 hour 90 day 365 day 365 day 365 day TCal ±1 °C TCal ±1 °C TCal ±1 °C TCal ±1 °C...
  • Page 26 8508A Service Manual [1] [2] [3] [10] Resistance - Normal Mode (Secondary Specifications) Temperature Coefficient Transfer Uncertainty 20 mins ±1 °C 5 °C - 15 °C Range Measurement Current 15 °C - 30 °C ± (ppm Reading 30 °C - 40 °C + ppm Range) ±...

  • Page 27: Temperature

    Introduction and Specifications Specifications Temperature [1] [2] [3] Temperature Readout [12] Typical Equivalent Temperature Measurement Uncertainty Absolute Resistance Measurement Uncertainty Nominal Resistance Range Resistance Accuracy 365 day Tcal ±1 °C Probe Type Temperature ± (°C) [11] ±(ppm Reading + m ) (°C) 95% Confidence Level 7.5 + 0.14...

  • Page 28: Read Rate And Additional Uncertainty

    1.0 + 0.5 0 + 5 Notes to Performance Specifications Fluke guarantees 8508A performance verification using specifications stated to 99 % confidence level. [1] Specifications apply for max resolution in each function, normal mode [2] Assumes 4 hour warm-up period [3] Input zero or offset null required whenever the temperature moves more than ±1 °C from the temperature at which the previous...

  • Page 29: Applying The Specifications

    Absolute specifications include the uncertainty of the standards used to perform calibration of the 8508A at manufacture and may be used to determine the uncertainty of measurements made with the 8508A for periods up to 1 year and over a temperature range of 5 C from calibration.

  • Page 30: Applying User's Calibration Uncertainties

    95 %. Check the applicable calibration uncertainties are stated at 95 % and then combine them with the 8508A 95 % Relative specifications. For example, if the 8508A is calibrated at 10 V DC with an uncertainty of 1.5 ppm at 95 %: The absolute uncertainty at 10 V for a period of 90 days...

  • Page 31: Ratio Measurements

    Applying the Specifications Ratio Measurements The 8508A Ratio mode will automatically take measurements of inputs applied to the front and rear terminals and display the result as a ratio in the voltage and resistance functions. The measurements can be made on the same range or different ranges. When...
  • Page 32 8508A Service Manual 1-22...

  • Page 33: Theory Of Operation

    Chapter 2 Theory of Operation Title Page Introduction......................2-3 Overall Functional Description................2-3 Main Assemblies ..................... 2-3 Power Supplies ....................2-6...
  • Page 34 8508A Service Manual...

  • Page 35: Introduction

    Theory of Operation Introduction Introduction This chapter provides a board-level theory of operation for the 8508A Reference Multimeter. Functional block diagrams supplement the text when appropriate. In addition to providing a conceptual overview of the Multimeter’s operation, the descriptions are helpful for troubleshooting and isolating problems to a board level.
  • Page 36 Relay Control and Optically Isolated Rear Panel Switching Relays Relay Drivers Serial Interface IEEE (GPIP) Keyboard and IEEE-488 Display Memory Serial (GPIB) A6 Rear Input A5 Bezel Assembly and Assembly A5A1 Display PCA avw003f.eps Figure 2-1. 8508A Functional Block Diagram...
  • Page 37 Theory of Operation Overall Functional Description A 16-pin cable (W3) enables serial control and measurement data to move between the A4 Digital PCA and the A1 DC PCA. Opto-isolators on the A1 DC PCA optically isolate the external control and display circuits of the Multimeter from the measurement circuits. This isolation minimizes problems associated with noise and current loops in the measurement circuits.

  • Page 38: Power Supplies

    8508A Service Manual measurement across the unknown resistor. Configuration relays on the A1 DC PCA perform the change in terminal connections between two- and four-wire measurements. The A3 Ohms PCA includes an alternative high-resistance measurement feature for resistance measurements above 20 M . These measurements use 10 times the standard stimulus current and result in a 10 times increase in the voltage across the resistor.
  • Page 39 Theory of Operation Overall Functional Description J150 J401 250 V ac Ohms J502 +15 V regulator +15 V dc +17 V -15 V dc 15 V regulator -18 V dc +36 V dc +36 V regulator -36 V dc 36 V regulator +8 V dc +5 V dc +5 V regulator...
  • Page 40 8508A Service Manual...

  • Page 41: Calibration And Verification

    Chapter 3 Calibration and Verification Title Page Introduction......................3-3 Calibration Overview................... 3-3 Calibration Interval and Performance ..............3-3 Calibration Points ....................3-3 Non-Nominal Values..................3-4 Enabling Access to Calibration Mode ..............3-4 Calibration Menus....................3-4 Accessing the Calibration Menus and Calibration Mode ........ 3-4 Calibration Menu.....................
  • Page 42 8508A Service Manual Applicable Verification Tolerance and Conditions ......... 3-32 Preparation....................... 3-33 DC Voltage Checks ..................3-33 AC Voltage Checks ..................3-35 Resistance Checks ................... 3-37 DC Current Checks..................3-40 AC Current Checks..................3-41 Frequency Checks ................... 3-43...

  • Page 43: Introduction

    Many Multimeter owners prefer using Fluke calibration services instead of maintaining their own standards to support their Multimeter.To help ensure optimum performance from the Multimeter, Fluke offers our calibration service at a variety of worldwide locations. Our worldwide service network provides fast efficient calibration to ensure low uncertainties and optimum accuracy consistent with the original calibration at manufacture.

  • Page 44: Non-Nominal Values

    8508A Service Manual Non-Nominal Values facility allows the user to set the calibration target to the value of the calibration source available. This facility is most useful when the user’s calibration source is not available at the nominal values specified, or when the user has knowledge of the actual output of the calibration source at the required points.

  • Page 45: Set Value Menu

    Calibration and Verification Calibration Menus This menu defines four menu keys: Indicates to the user that the calibration point is automatically set according Auto to the amplitude (and frequency in ACV) of the signal detected. Auto is the default selection on entry to the menu.

  • Page 46: Spot Cal Menu

    8508A Service Manual SPOT CAL Menu This menu is obtained by pressing the Set key in the CALIBRATION menu when the Multimeter is in ACV Spot Frequency mode. It provides a means of calibrating the Multimeter at any of six user-specific spot frequencies, at non-nominal calibration values for each ACV range.

  • Page 47: Special Calibration

    Calibration and Verification Calibration Menus ±10 % of the stored frequency is accuracy enhanced by reducing frequency response flatness errors. Calibrate the spot at a new frequency: To calibrate the spot at a new frequency, change the input signal to the desired new frequency and press as before.

  • Page 48: Hvlin Menu

    8508A Service Manual adj138f.eps SER# Menu menu provides the selection: SER# Stores the new serial number, de-activates the keyboard, and reverts to the Enter SPCL menu. Reverts to the SPCL menu, leaving the old serial number intact. Quit Hvlin Menu This menu sequence is obtained by selecting from the SPCL menu.

  • Page 49: Routine Calibration

    This routine calibration procedure describes the calibration points and sequence of operations required to calibrate the Multimeter and assumes calibration references of adequate traceable uncertainty are available – in this case a Fluke 5720A calibrator and 5725A amplifier used with an 8508A-7000 Calibration Kit. The procedure assumes the user is able to calibrate and characterize the calibration standards, without describing the process required to do so.

  • Page 50: Equipment Required For Calibration

    [1] Availability of a 1 MHz frequency reference signal may be required for 5720A frequency locking during 8508A frequency calibration procedure. [2] Best uncertainties are obtained by characterizing the outputs of the 5720A and 5725A at the points used for 8508A calibration. Alternate equipment may be used, but users should ensure it provides adequate calibration uncertainties.

  • Page 51: Interconnections

    To meet user's need, just one range on one function can be calibrated. Interconnections The Fluke 8508A-7000K Calibration kit contains a specially designed lead set which connects directly to the terminals of the Multimeter, the 5720A, and the 5725A for the purpose of Multimeter calibration.
  • Page 52 When calibrating the 2 G and 20 G resistance ranges the 1 G standard resistor supplied in the Fluke 8508A-7000K Calibration kit plugs directly into the Multimeter’s front input terminals, without any interconnecting leads. If alternate resistance standards are used for resistance calibration, refer to the resistance-measurements section of Chapter 3 Making Measurements for connection details.
  • Page 53 Calibration and Verification Routine Calibration Green Black White Blue Green White Link guard Black and ground terminal Blue CURRENT Link guard OUTPUT and ground terminal White CURRENT OUTPUT Green adj381f.eps Figure 3-1. Equipment Connections Required for Calibration 3-13...

  • Page 54: Adc Calibration

    8508A Service Manual ADC Calibration ADC (analog to digital converter) calibration aligns the different resolutions available from the Multimeter’s analog to digital converter, so that there are no significant differences in readings when changing resolutions with a constant input value. It is...
  • Page 55 200 mV range and work up to the 1kV range, as shown in Table 3-3. Table 3-3. DC Voltage Calibration Points and Sequence 8508A Range Point Voltage 200 mV...

  • Page 56: Ac Voltage Calibration

    8508A Service Manual Range Gain Points 1. On the Calibrator, select the positive Range Gain point Output value. 2. On the Multimeter, Press to revert to menu. CALIBRATION 3. Select on the CALIBRATION menu 4. Use the numeric keys with the...
  • Page 57 Calibration and Verification Routine Calibration Table 3-4. AC Voltage Calibration Points and Sequence 8508A Range Point Voltage Frequency 200 mV Zero (5 % Range) 10 mV 1 kHz Range Gain LF 100 mV 1 kHz Range Gain HF 100 mV 60 kHz Zero (0.5 % Range)

  • Page 58: Resistance Calibration

    A 1 G standard resistor provided in the 8508A-7000K calibration kit is used for ranges above 200 M as the highest resistance available from the 5720A calibrator is 100 M . Refer to Table 3-5 for the resistance calibration points and sequence.
  • Page 59 Calibration and Verification Routine Calibration Initial Setup and Connections 1. Press the key and select the range. 2. Press the key and select CONFIG Filt 3. In calibration mode the resolution defaults to in the resistance function. It is RESL7 recommended that this resolution is used for calibration of all resistance ranges.
  • Page 60 8508A Service Manual Calibration is complete when the Busy legend goes out and the calibrated measurement is displayed Range Gain Point 1. On the Calibrator, select the Range Gain point resistance value. Alternatively if using a standard resistor re-connect the standard resistor to measure its resistance. (For the 2 G range the 8508-7000K 1 G standard resistor is used in place of the calibrator.
  • Page 61 Calibration and Verification Routine Calibration Zero Point 1. On the Multimeter, select the required range. 2. On the Calibrator, select zero and Operate. Alternatively if using a standard resistor connect the standard resistor for a 4-wire resistance zero. (For the 200 M and 2 G ranges, de-select Ex SNS on the calibrator and de-select n the Multimeter.)
  • Page 62 8508A Service Manual Zero Point 1. On the Multimeter, select the required range. 2. On the Calibrator, select zero and Operate. Alternatively if using a standard resistor connect the standard resistor for a 4-wire resistance zero. 3. On the Multimeter, press to enter the menu.
  • Page 63 Calibration and Verification Routine Calibration Zero Point 1. On the Multimeter, select the required range. 2. On the Calibrator, select zero and Operate. Alternatively if using a standard resistor connect the standard resistor for a 4-wire resistance zero. 3. On the Multimeter, press to enter the menu.
  • Page 64 8508A Service Manual For the 2 G range use the 1 G standard resistor in place of the calibrator. To avoid the requirement for a 10 G standard, the 20 G range is automatically calibrated when the 2 G range gain calibration is triggered. It is also necessary for the 100 M and 1 G Normal ranges to be calibrated prior to the 2 G HiV range for the result to be valid.

  • Page 65: Dc Current Calibration

    Calibration and Verification Routine Calibration 5. Press to initiate the calibration operation. SAMPLE Calibration is complete when the Busy legend goes out and the calibrated measurement is displayed. 6. On the Calibrator, set STANDBY 7. Press the key to revert to the ranges menu. DC Current Calibration XW Warning The Calibrator can deliver a lethal electric shock.
  • Page 66 8508A Service Manual Table 3-6. DC Current Calibration Points and Sequence 8508A Range Point Current 200 A Zero Range Gain +ve +100 A Range Gain -ve -100 A 2 mA Zero 0 mA Range Gain +ve +1 mA Range Gain -ve...

  • Page 67: Ac Current Calibration

    Calibration and Verification Routine Calibration Range Gain Points 1. On the Calibrator, select the positive Range Gain point Output value. 2. On the Multimeter, Press to revert to menu. CALIBRATION 3. Select on the CALIBRATION menu 4. Use the numeric keys with the menu to key in the true output value of SET VALUE the calibrator at the range gain value, then press Enter.

  • Page 68: Frequency Calibration

    8508A Service Manual Table 3-7. AC Current Calibration Points and Sequence 8508A Range Point Current Frequency Zero (5 % Range) 300 Hz 200 A 10 A Range Gain 300 Hz 100 A 2 mA Zero (0.5 % Range) 300 Hz...

  • Page 69: Exit From Calibration Mode And Non-Volatile Input Offset Adjustment

    Calibration and Verification Routine Calibration Alternatively, the 1MHz frequency reference may be used directly as an input signal for the Multimeter for frequency calibration. Initial Setup and Connections 1. Press the key, select the range. 2. Confirm that the Multimeter is configured for internal guard (External Guard is deselected) by checking that the legend does not appear on the left-hand Ext Grd...

  • Page 70: Cal Due Date Entry And Calibration Mode Disable

    8508A Service Manual 6. Press the key and select . Repeat steps 3 and 4. CONFIG Filt 7. Press the key and select . Repeat steps 3 and 4. CONFIG 8. Press the key, select and de-select . Repeat steps 3 and 4.

  • Page 71: Performance Verification

    This routine performance verification procedure describes the test points and sequence of operations required to check the Multimeter and assumes calibration references of adequate traceable uncertainty are available – in this case a Fluke 5720A calibrator and 5725A amplifier used with an 8508A-7000 Calibration Kit. The procedure assumes the user is able to calibrate and characterize the calibration standards, without describing the process required to do so.

  • Page 72: Equipment Requirements

    Multimeter at the Fluke factory. They are applicable to a verification performed within a period of 365 days from calibration and at a temperature within 1 C of the temperature at which calibration was performed (23 C for calibrations performed by Fluke).

  • Page 73: Preparation

    Calibration and Verification Performance Verification * Fluke guarantees the Multimeter’s performance verification using specifications stated to 99 % confidence level. Preparation 1. Allow the Multimeter to warm-up under power in the specified environment for at least 4 hours. 2. Press the...
  • Page 74 7. Note the Multimeter’s reading. Compare the result with the allowable tolerance, taking into account any known error from nominal of the calibrator for this output. 8. Set the calibrator output to STANDBY Table 3-8. DC Voltage Verification Points and Sequence 8508A Range Voltage Tolerance 200 mV 0 mV...

  • Page 75: Ac Voltage Checks

    Calibration and Verification Performance Verification AC Voltage Checks XW Warning The Calibrator can deliver a lethal electric shock. To avoid electric shock when performing the following calibration procedures: Never touch any lead or terminal unless you are absolutely certain that no dangerous voltage is present. Make sure that signal leads are in a safe condition before you handle them in any way.
  • Page 76 8508A Service Manual Table 3-9. AC Voltage Verification Points and Sequence 8508A Range Voltage Frequency 8508A Filter Tolerance 200 mV 100 mV 20 Hz 10 Hz 0.0195 mV 100 mV 55 Hz 40 Hz 0.0175 mV 100 mV 1 kHz 100 Hz 0.0149 mV...

  • Page 77: Resistance Checks

    Calibration and Verification Performance Verification Table 3-9. AC Voltage Verification Points and Sequence (cont) 8508A Range Voltage Frequency 8508A Filter Tolerance 200V 100 V 20 Hz 10 Hz 0.0144 V 100 V 55 Hz 40 Hz 0.0119 V 100 V...
  • Page 78 8508A Service Manual Procedure Perform the following sequence for each resistance mode and each range, as listed in Table 3-10, starting with the 2 range and working up to the 2 G range for the Normal and Normal LoI resistance modes. Then continue the sequence for the Tru and Tru LoI modes, starting with the 2 range and working up to the 20 k range.
  • Page 79 , and CONFIG Filt RESL7 21. Repeat steps 3 – 9 for the ranges. Table 3-10. Resistance Verification Points and Sequence 8508A Range Resistance Tolerance Normal and Tru Normal LoI and Tru LoI Perform input zero operation to calibrator range locked zero output 0.0000240...

  • Page 80: Dc Current Checks

    8508A Service Manual Table 3-10. Resistance Verification Points and Sequence (cont) 8508A Range Resistance Tolerance 20 M Perform input zero operation to calibrator range locked zero output 10 M 0.0000202 M 200 M Perform input zero operation to calibrator range locked zero output 100 M 0.0000870 M...

  • Page 81: Ac Current Checks

    7. Note the Multimeter’s reading. Compare the result with the allowable tolerance, taking into account any known error from nominal of the calibrator for this output. Table 3-11. DC Current Verification Points and Sequence 8508A Range Current Tolerance 200 A...
  • Page 82 4. Repeat steps 2 – 4 for each point to be verified on the Multimeter’s range to be verified. 5. Repeat steps 1 – 5 for each Multimeter range to be verified. 6. Set the calibrator output to STANDBY Table 3-12. AC Current Verification Points and Sequence 8508A Range Current Frequency Tolerance 300 Hz 200 A 100 A 0.0830 A...

  • Page 83: Frequency Checks

    2V range 4. Press the key. Select CONFIG Tfer On, Filt 40Hz. 5. Confirm that the 8508A is configured for internal guard (External Guard is deselected) by checking that the legend does not appear on the left-hand Ext Grd display.
  • Page 84 8508A Service Manual 3-44...
  • Page 85 A Message From Fluke Corporation Some semiconductors and custom IC's can be damaged by electrostatic discharge during handling. This notice explains how you can minimize the chances of destroying such devices 1. Knowing that there is a problem.
  • Page 86 8. WHEN REMOVING PLUG-IN ASSEMBLIES 5. USE STATIC SHIELDING CONTAINERS FOR HANDLE ONLY BY NON-CONDUCTIVE HANDLING AND TRANSPORT. EDGES AND NEVER TOUCH OPEN EDGE CONNECTOR EXCEPT AT STATIC-FREE WORK STATION. PLACING SHORTING STRIPS ON EDGE CONNECTOR HELPS PROTECT INSTALLED S.S. DEVICES. 6.

  • Page 87: Maintenance

    Chapter 4 Maintenance Title Page Introduction......................4-3 Access Procedures ....................4-3 Before You Start....................4-3 Cabling and Wiring Connections ..............4-4 Removing the A1 DC PCA ................4-5 Removing the A2 AC PCA ................4-6 Removing the A3 Ohms PCA ................. 4-7 Removing the A4 Digital PCA................
  • Page 88 8508A Service Manual...

  • Page 89: Introduction

    Maintenance Introduction Introduction This chapter contains access procedures for replaceable assemblies (PCAs) and error messages assocated with the self-test procedure. All of the access procedures describe how to remove a PCA or assembly. In all cases, unless otherwise noted, the re- assembly/replacement procedure is a logical reversal of the removal procedure.

  • Page 90: Cabling And Wiring Connections

    8508A Service Manual Cabling and Wiring Connections To help avoid making incorrect cable connections during reassembly, refer to the internal wiring and cabling diagram shown in Figure 4-1. FRONT A5A1 SENSE INPUT J201 J202 GUARD A5A1 Display PCA W6 (16)

  • Page 91: Removing The A1 Dc Pca

    Maintenance Access Procedures Removing the A1 DC PCA Use the following procedure to remove the A1 DC PCA. See Figure 4-2. 1. Position the unit on the work surface so it is bottom-side up. 2. Remove both rear feet A. a.

  • Page 92: Removing The A2 Ac Pca

    8508A Service Manual Removing the A2 AC PCA Use the following procedure to remove the A2 AC PCA. See Figure 4-3. 1. Position the unit on the work surface so it is top-side up. 2. Remove both rear feet. A a.

  • Page 93: Removing The A3 Ohms Pca

    Maintenance Access Procedures Removing the A3 Ohms PCA Use the following procedure to remove the A3 Ohms PCA. See Figure 4-4. 1. Position the unit on the work surface so it is bottom-side up. 2. Remove both rear feet. A a.

  • Page 94: Removing The A4 Digital Pca

    8508A Service Manual Removing the A4 Digital PCA Use the following procedure to remove the A4 Digital PCA. See Figure 4-5. 1. Position the unit on the work surface so it is top-side up. 2. Remove both rear feet. A a.

  • Page 95: Removing The A5 Bezel Assembly

    Maintenance Access Procedures Removing the A5 Bezel Assembly Use the following procedure to remove the A5 Bezel Assembly. See Figure 4-6. 1. Position the unit on the work surface so it is bottom-side up. 2. Remove both rear feet. A a.

  • Page 96: Removing The A5A1 Display Pca

    8508A Service Manual Removing the A5A1 Display PCA Use the following procedure to remove the A5A1 Display PCA. See Figure 4-7. 1. Remove the A5 Bezel Assembly (described earlier in this chapter). 2. Remove the seven small self-threading Philips screws holding the A5A1 Display PCA to the plastic bezel (front panel).

  • Page 97: Removing The A6 Rear Input Assembly

    Maintenance Access Procedures Removing the A6 Rear Input Assembly Use the following procedure to remove the A6 Rear Input Assembly. See Figure 4-8. 1. Position the unit on the work surface so it is bottom-side up. 2. Remove both rear feet. A a.

  • Page 98: Fuse Replacement And Line-Voltage Selection

    8508A Service Manual Fuse Replacement and Line-Voltage Selection WCaution To avoid fire hazard, use only the fuse arrangements that appear in the fuse specification Tables 4-1 and 4-2 below. Additionally, the supply network must be fused at a maximum of 16 A, and if the power cable plug is internally fused, a 5 A fuse must be fitted in the power cable plug.

  • Page 99: Rear-Input Current Fuse F2 (Rear Inputs Option)

    Device Dependant Errors. All error conditions other than Fatal Errors are recoverable. For help in determining what to do in the event of a self-test error, make a note of the full error message and contact your nearest Fluke Service Center. Self-Test Errors When a Self-Test is run and successfully completed no error messages result and the Multimeter is considered operational.
  • Page 100 8508A Service Manual Test No 28 Err 2281 P011 10V Range Positive Gain Check Test No 29 Err 2291 P012 10V Range Negative Gain Check Test No 30 Err 2301 P013 100V Range Positive Gain Check Test No 31 Err 2311...
  • Page 101 Maintenance Self Test AC VOLTS Test No 80 Err 2801 P015 100mV AC Range: Zero Input Check Test No 81 Err 2811 P016 100mV AC Range: +179mV DC Input Checks at PreAmp Output Test No 82 Err 2821 P017 100mV AC Range: -179mV DC Input Checks at PreAmp Output Test No 83 Err 2831...

  • Page 102: Fatal Errors

    When a fatal error occurs the processor halts the operation of the multimeter. Cycling the power off and on may clear the message. Howerver, fatal errors are generally caused by hardware or software faults which require repair by at a Fluke Service Center. 9000 System Kernel Fault Addr id This error is generated for system queue errors, stack overflows etc.
  • Page 103 Maintenance Self Test 9005 Serial Interface Fault Addr id When this fatal error occurs the system will continuously try to repeat whatever it was doing - the user interface will be inoperative. See Tabe 4-6 for descriptions of the serial interface errors. Table 4-6.

  • Page 104: Execution Errors

    8508A Service Manual 9006 - Serial Loop Mismatch xxxxxxxx id xxxxxxxx is the actual data received in binary format. See Table 4-7 for descriptions of the serial loop mismatch errors. Table 4-7. Serial Loop Mismatch Errors Fault U901_C pattern mismatch – should be 00000001 (00000000 if rear fitted) U901_B pattern mismatch –...

  • Page 105: Device Dependant Errors

    Maintenance Self Test Table 4-8. Execution Errors 1000- 1024- EXE queue empty when recalled Illegal Range/Input Combination 1001- 1025- Option not installed Auto not available in Tru ratio 1002- 1026- Calibration disabled Probe identity unrecognized 1005- 1027- Input Zero not allowed in Scan Input Zero not allowed in PRT 1007- 1028-...
  • Page 106 8508A Service Manual Table 4-9. Device Dependent Errors Correction Errors 2000- Error During Zero Cal The input signal was outside : Zero +/- 1 % of Full Range 2001- Error During Gain+ Cal The input signal was outside : +full range +/- 10 %...

  • Page 107: List Of Replaceable Parts

    Chapter 5 List of Replaceable Parts Title Page Introduction......................5-3 How to Obtain Parts..................... 5-3 How to Contact Fluke ..................5-3 Parts Lists......................5-4...
  • Page 108 8508A Service Manual...

  • Page 109: Introduction

    List of Replaceable Parts Introduction Introduction This chapter contains an illustrated list of replaceable parts for the 8508A Reference Multimeter to the board level only. Parts are listed by assembly; alphabetized by reference designator. Each assembly is accompanied by an illustration showing the location of each part and its reference designator.

  • Page 110: Parts Lists

    Description Fluke stock number Total quantity Any special notes (i.e., factory-selected part) W Caution A * symbol indicates a device that may be damaged by static discharge. Table 5-1. 8508A Final Assembly Reference Description Fluke Notes Designator Part No Top Cover...
  • Page 111 List of Replaceable Parts Parts Lists MP10 avw025.eps Figure 5-1. 8508A Final Assembly...
  • Page 112 8508A Service Manual Table 5-2. 8508A Chassis Assembly Reference Description Fluke Tot Qty Notes Designator Part No DC PCA 1988709 AC PCA 1988727 Ohms PCA 1988748 Digital PCA 1988730 Bezel Assembly 1605337 Rear Input Assembly (optional) 2398049 A401 Reference Module POS Assembly...
  • Page 113 List of Replaceable Parts Parts Lists AC PCA Ohms PCA Top View STICK OVER SMALL HOLES Bottom view DC PCA avw026f.eps Figure 5-2. 8508A Chassis Assembly...
  • Page 114 8508A Service Manual DC PCA A401 Bottom view A401 FORM RIBBON CABLES AS SHOWN AND CONNECT TO CONNECTORS ON REAR OF DISPLAY BOARD. WHITE & GREEN BLUE BROWN BLACK avw027f.eps Figure 5-2. 8508A Chassis Assembly (cont)
  • Page 115 List of Replaceable Parts Parts Lists Digital PCA NOT REQUIRED IF REAR INPUT FITTED avw028.eps Figure 5-2. 8508A Chassis Assembly (cont)
  • Page 116 8508A Service Manual Table 5-3. A5 Bezel (front panel) Assembly Reference Fluke Description Tot Qty Notes Designator Part No Display PCB Assembly 1988711 C1, C2 Capicator, ceramic, 470 pF 10% 2 kV 2397993 Screws, 8/32 x 3/8 295105 Screw, K25 x 8, POZIPAN SZP, ST...
  • Page 117 List of Replaceable Parts Parts Lists RED WIRE BLACK WIRES - FIT THIN WIRE UNDER THICK WIRE PINK WIRE BROWN WIRE BLUE WIRE WHITE WIRE ALL WIRES EXCEPT GREEN LOOP ONCE THROUGH FERRITE GREEN WIRE NOTE !! POSITION CAPACITOR AWAY FROM OTHER TERMINALS. avw029f.eps Figure 5-3.
  • Page 118 8508A Service Manual Table 5-4. A6 Rear Input Assembly (optional) Reference Description Fluke Tot Qty Notes Designator Part No Rear Input PCA 2399180 C1, C2 Capicator CD 470 pF 10% 2 kV 2397993 Fuse 1.6 A 250 V 20 mm...
  • Page 119 List of Replaceable Parts Parts Lists 8 wires with terminals GREEN WHITE BLUE BLACK ORANGE BROWN ORANGE WIRE GREEN WIRE ORANGE WIRE BLACK WIRE WHITE WIRE RED WIRE BLUE WIRE BROWN WIRE J1, J3, J5 J2, J4 Black Blue avw030f.eps Figure 5-4.
  • Page 120 8508A Service Manual 5-14...

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