Fluke 87 Series IV User manual

®
87 & 89 Series IV
True RMS Multimeter
Service Manual
PN 676137
May 1999
© 1999 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies.

Limited Warranty & Limitation of Liability
Fluke Corporation (Fluke) warrants this product to be free from defects in material and workmanship under normal use and
service for the life of the product. This warranty extends only to the original buyer or end-user customer of a Fluke
authorized reseller, and does not apply to fuses, 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 on appropriate Fluke instruments 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.
Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, or 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 (FCA 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 (FCA 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 (FCA Shipping Point).
Warranty service is available outside the United States only if product was purchased through a Fluke Authorized Sales
Outlet in the country of use or the applicable Fluke international price was paid. Product transported from the United
States for which the applicable Fluke international price was not paid must be returned to the U.S. to receive warranty
service, at the shipment expense and risk of Buyer. Fluke reserved 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.
THIS WARRANTY IS PURCHASER’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 at www.fluke.comor call Fluke using the phone
numbers listed below:
1-888-99-FLUKE (1-888-993-5853) in USA and Canada
[phone] in Europe
[phone] Japan
[phone] Singapore
[phone] in other countries
Fluke Corporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett WA 98206-9090 5602 B.D.
U.S.A Eindhoven, The Netherlands

i
Table of Contents
Title Page
Introduction ...................................................................................................... 1
Precautions and Safety Information.................................................................. 2
International Symbols....................................................................................... 2
Safety Information............................................................................................ 3
Specifications.................................................................................................... 4
Accuracy ...................................................................................................... 4
Feature Summary ......................................................................................... 4
General Specifications.................................................................................. 5
Basic Specifications...................................................................................... 6
AC Voltage and Decibel Specifications....................................................... 6
AC Current Specifications............................................................................ 7
DC Current Specifications............................................................................ 7
Resistance and Conductance Specifications................................................. 8
Capacitance and Diode Function Specifications .......................................... 8
Frequency, Duty Cycle, & Pulse Width Specifications................................ 8
Temperature Specifications.......................................................................... 9
MIN MAX Recording Specifications........................................................... 9
Frequency Counter Sensitivity ..................................................................... 9
Burden Voltage (A, mA, µA)....................................................................... 10
Input Characteristics..................................................................................... 10
Required Equipment......................................................................................... 11
Basic Maintenance............................................................................................ 12
Opening the Meter Case............................................................................... 12
Removing and Reinserting the Circuit Board Assembly.............................. 12
Replacing the LCD....................................................................................... 13
Reassembling the Meter Case....................................................................... 14
Testing Fuses (F1 and F2)............................................................................ 14
Replacing Fuses............................................................................................ 15
Replacing the Batteries................................................................................. 15
Cleaning ....................................................................................................... 16
Performance Tests ............................................................................................ 17
Testing the Display....................................................................................... 17
Backlight Test .............................................................................................. 17
Current Terminal Sensing Test..................................................................... 17
Keypad Test.................................................................................................. 18
Verification of the IR Communication Port ................................................. 18

87 & 89 Series IV
Service Information
ii
Testing Temperature..................................................................................... 18
Testing Voltage, Current, Resistance, Capacitance and Diode Functions.... 19
Calibration........................................................................................................ 22
Keypad Interface .......................................................................................... 22
General Procedure........................................................................................ 23
Special Requirements................................................................................... 24
Calibration Inputs......................................................................................... 24
Remote Interface .......................................................................................... 26
Temperature Calibration............................................................................... 26
Setup ........................................................................................................ 26
Procedure ................................................................................................. 27
Re-Programming Serial Number or Model Number .................................... 27
Parts and Accessories ....................................................................................... 28

iii
List of Tables
Table Title Page
1. International Symbols........................................................................................... 2
2. Required Tools and Equipment............................................................................. 11
3. Temperature Test Input and Display..................................................................... 18
4. Performance Test Steps......................................................................................... 19
5. Calibration Inputs.................................................................................................. 24
6. Replacement Parts and Accessories...................................................................... 28

87 & 89 Series IV
Service Information
iv

v
List of Figures
Figure Title Page
1. Removing LCD Mask to Access LCD.................................................................. 13
2. Testing the Current Fuses...................................................................................... 15
3. Battery and Fuse Replacement.............................................................................. 16
4. Display Test.......................................................................................................... 17
5. Locating Recessed Calibration Button.................................................................. 22
6. Calibration Display............................................................................................... 23
7. Replacement Parts and Accessories...................................................................... 29

87 & 89 Series IV
Service Information
vi

1
Introduction
Warning
To avoid shock or injury, do not perform the verification tests
or calibration procedures described in this manual unless you
are qualified to do so.
The information provided in this document is for the use of
qualified personnel only.
Caution
The 87 & 89 Series IV Multimeters contain parts that can be
damaged by static discharge.
Follow the standard practices for handling static sensitive
devices.
The information in this manual deals with the Fluke Models 87 & 89 Series IV True
RMS Multimeters, (hereafter referred to as “the meter”). Information provided includes:
•Precautions and safety information
•Specifications
•Basic maintenance (cleaning, replacing the battery and fuses)
•Performance test procedures
•Calibration and calibration adjustment procedures
•Accessories and replaceable parts
For complete operating instructions, refer to the Model 87 & 89 Series IV Users Manual.
To contact Fluke, call:
1-888-993-5853 in USA and Canada
[phone] in Europe
[phone] Japan
[phone] Singapore
[phone] in other countries
For additional information about Fluke, its products and services, visit Fluke’s web site
at:
www.fluke.com

87 & 89 Series IV
Service Manual
2
Precautions and Safety Information
Use the Meter only as described in the Users Manual. If you do not do so, the protection
provided by the Meter may be impaired.
Read the “Safety Information” page before servicing this product.
In this manual, a Warning identifies conditions and actions that pose hazard(s) to the
user; a Caution identifies conditions and actions that may damage the Meter or the test
instruments.
International Symbols
International symbols used on the Meter and in this manual are explained in Table 1.
Table 1. International Symbols
Symbol Meaning Symbol Meaning
Alternating current Earth ground
Direct current Fuse
Alternating or direct current Conforms to European Union
directives
Refer to the manual. Important
information. Conforms to relevant Canadian Standards Association directives
Inspected and licensed by TÜV
Product Services. Double insulated
Battery Underwriters Laboratories, Inc.

Safety Information
3
Safety Information
Warnings and Precautions
To avoid possible electric shock or personal injury, follow these guidelines:
•Do not use the Meter if it is damaged. Before you use the Meter, inspect the case.
Look for cracks or missing plastic. Pay particular attention to the insulation
surrounding the connectors.
•Inspect the test leads for damaged insulation or exposed metal. Check the test
leads for continuity. Replace damaged test leads before you use the Meter.
•Do not use the Meter if it operates abnormally. Protection may be impaired. When in
doubt, have the Meter serviced.
•Do not operate the Meter around explosive gas, vapor, or dust.
•Do not apply more than the rated voltage, as marked on the Meter, between
terminals or between any terminal and earth ground.
•Before use, verify the Meter’s operation by measuring a known voltage.
•When measuring current, turn off circuit power before connecting the Meter in the
circuit. Remember to place the Meter in series with the circuit.
•When servicing the Meter, use only specified replacement parts.
•Use caution when working above 30 V ac rms, 42 V peak, or 60 V dc. Such voltages
pose a shock hazard.
•Avoid working alone.
•When using the probes, keep your fingers behind the finger guards on the probes.
•Connect the common test lead before you connect the live test lead. When you
disconnect test leads, disconnect the live test lead first.
•Remove test leads from the Meter before you open the battery door.
•Do not operate the Meter with the battery door or portions of the cover removed or
loosened.
•To avoid false readings, which could lead to possible electric shock or personal
injury, replace the batteries as soon as the low battery indicator ( ) appears.
•Use only type AA batteries, properly installed in the Meter case, to power the Meter.
Caution
To avoid possible damage to the Meter or to the equipment under test, follow these
guidelines:
•Disconnect circuit power and discharge all high-voltage capacitors before testing
resistance, continuity, diodes, or capacitance.
•Use the proper terminals, function, and range for your measurements.
•Before measuring current, check the Meter's fuses and turn power OFF to the
circuit before connecting the Meter to the circuit.

87 & 89 Series IV
Service Manual
4
Specifications
Accuracy
Accuracy is specified for a period of one year after calibration, at 18 °C to 28 °C (64 °F
to 82 °F), with relative humidity to 90 %. Accuracy specifications are given as:
±( [ % of reading ] + [ number of least significant digits ] )
AC mV, AC V, AC µA, AC mA, and AC A specifications are ac-coupled, true rms and are
valid from 5 % of range to 100 % of range. AC crest factor can be up to 3.0 at full-scale, 6.0
at half-scale, except the 3000 mV and 1000 V ranges where it is 1.5 at full scale, 3.0 at half-
scale.
Feature Summary
Feature Description
Dual Digital Displays
Analog Bar Graph
Primary: 50,000 counts
Secondary: 5,000 count
Bar graph: 51 segments, updates 40 times/second
Backlight with 2 brightness adjustment Bright-white backlight for clear readings in poorly lighted
areas
Fast Autorange Meter automatically selects best range
AC+DC true rms, ac rms specified to 100
kHz Choices for AC only, AC and DC dual display, or AC+DC readings
dBm, dBV User-selectable impedance references for dBm
AutoHOLD Holds readings on display
Continuity / Open test Beeper sounds for resistance readings below threshold, or
to indicate a momentary open circuit
Fast Bar Graph 51 segments for peaking and nulling
Duty cycle / Pulse width Measure the time signal is on or off in % or milliseconds
MIN MAX Mode
FAST MN MX with 24-hour time stamp
Record maximum, minimum, and average values.
24-hour clock for MAX or MIN, elapsed time for AVG.
FAST MN MX captures peaks to 250 µsec.
Close-Case Calibration No internal adjustments needed
Battery / Fuse Access Door Battery or fuse replaceable without voiding calibration
Hi-Impact Overmolded Case Protective holster features

Specifications
5
General Specifications
Maximum Voltage between any Terminal
and Earth Ground 1000 V ac/dc
Surge Protection 8 kV peak per IEC 1010.1-92
Fuse Protection for mA or µA inputs
Fuse Protection for A input 44/100 A, 1000 V FAST Fuse 11 A, 1000 V FAST Fuse
Display (LCD) Digital: 50000/5000 primary display,
5000 counts secondary display;
updates 4/second.
Analog: 51 segments, updates 40/second.
Temperature Operating: -20 °C to +55 °C;
Storage: -40 °C to +60 °C
Altitude Operating: 2000 m;
Storage: 10,000 m
Temperature Coefficient 0.05 x (specified accuracy) / °C (<18 °C or >28 °C)
Electromagnetic Compatibility (EMC) Susceptibility and Emissions: Commercial Limits per
EN61326-1
Relative Humidity 0 % to 90 % (0 °C to 28 °C);
0 % to 70 % (28 °C to 55 °C)
Battery Type 4 AA Alkaline, NEDA 15A or LR6
Battery Life 72 hrs typical (with backlight off)
Shock Vibration Per MIL-T-PRF 28800 for Class II instruments
Size 3.94 in x 8 in x 1.97 in (10.0 cm x 20.3 cm x 5.0 cm)
(Not Including Accessory Mount)
Weight 1.2 lbs (545 g)
Case Sealing IP-42 per IEC 529, Section 3
Warranty Lifetime
Calibration Interval 1 year
Compliances Complies with ANSI/ISA S82.01-94, CSA 22.2 No. 1010.1-
92 to 1000 V Overvoltage Category III, Pollution Degree 2.*
Certifications (listed and pending) CSA per standard CSA/CAN C22.2 No. 1010.1-92
UL per standard UL3111-1 (pending)
TÜV per standard EN 61010 Part 1-1993 (pending)
*CAT III: OVERVOLTAGE (Installation) Category III, Pollution Degree 2 per IEC1010-1 refers to the level of Impulse
Withstand Voltage protection provided. Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed installations.
Examples include electricity meter and primary over-current protection equipment.

87 & 89 Series IV
Service Manual
6
Basic Specifications
Function Ranges/Description
DC Voltage 0 to 1000 V
AC Voltage, true RMS 15 mV to 1000 V – 100 kHz bandwidth
Basic Accuracy DC voltage: 0.025 %
AC voltage: 0.4 %
DC Current 0 to 10 A (20 A for 30 seconds)
AC Current, true RMS 25 µA to 10 A (20 A for 30 seconds)
Resistance 0 to 30 MΩ
Conductance 0 to 50 nS
Capacitance 0.001 nF to 50 mF
Diode Test 3.1 V
Temperature −200 °C to 1350 °C (−328 °F to 2462 °F)
Frequency 0.5 Hz to 1000 kHz
LOGGING Intervals
(Model 89 only) At least 288 intervals may be stored. Up to 700 unstable event values are automatically added to LOGGING memory for
viewing only through optional PC software. Additional intervals
will be logged if the signal is stable.
SAVE Readings
(Model 89 only) Up to 100 readings may be saved by the user in a memory separate from LOGGING memory. These readings may be
viewed using VIEW MEM.
AC Voltage and Decibel Specifications
Accuracy
Function Range Resolution 45Hz-
1 kHz 20-45 Hz 1-10 kHz 10-20 kHz 20-100 kHz
AC mV 1, 2 500.00 mV 0.01 mV 0.4 % + 40 2 % + 80 5 % + 40 5 % + 40 6 % + 40
3000.0 mV 0.1 mV 0.4 % + 40 2 % + 80 0.4 % + 40 1.5 % + 40 6 % + 40
AC V1, 2 5.0000 V 0.0001 V 0.4 % + 40 2 % + 80 0.4 % + 40 1.5 % + 40 6 % + 40
50.000 V 0.001 V 0.4 % + 40 2 % + 80 0.4 % + 40 1.5 % + 40 6 % + 40
500.00 V 0.01 V 0.4 % + 40 2 % + 80 0.4 % + 40 Not specified Not specified
1000.0 V 0.1 V 0.4 % + 40 2 % + 80 0.4 % + 40 Not specified Not specified
dBm 600 Ω−56 to −6 0.01 dB 0.1 dB 0.2 dB 0.5 dB 0.5 dB 0.5 dB
−6 to +34 0.01 dB 0.1 dB 0.2 dB 0.1 dB 0.2 dB 0.5 dB
+34 to +60 0.01 dB 0.1 dB 0.2 dB 0.1 dB Not specified Not specified
1. For the 5,000 count mode, divide the number of least significant digits (counts) by 10.
2. A residual reading of 8 to 80 digits with leads shorted, will not affect stated accuracy above 5 % of range.

Specifications
7
AC Current Specifications
Accuracy
Function Range Resolution 45-1 kHz 20-45 Hz 1-20 kHz 20 kHz-100 kHz
AC µA 500.00 µA 0.01 µA 0.75 % + 20 1 % + 20 0.75 % + 20 6 % + 40
5,000 µA0.1µA 0.75 % + 5 1% + 5 0.75 % + 10 2 % + 40
AC mA 50.000 mA 0.001 mA 0.75 % + 20 1% + 20 0.75 % + 20 9 % + 40
400.00 mA 10.01 mA .75 % + 5 1% + 5 1.5 % + 10 4 % + 40
AC A 5.0000 A 0.0001 A 1.5 % + 20 1.5% + 20 6 % + 40 Not Specified
10.000 A 20.001 A 1.5 % + 5 1.5% + 5 5 % + 10 Not Specified
1. 500.00 mA overload for 30 seconds maximum.
2. 20 A overload for 30 seconds maximum.
DC Current Specifications
Accuracy Accuracy Dual Display
AC or AC+DC6
Function Range Resolution
DC 20 - 45 Hz 45 Hz - 1 kHz 1 - 20 kHz
DC mV 500.00 mV 0.01 mV 0.03 % + 2 42 % + 80 0.6 % + 40
3000.0 mV 0.1 mV 0.025 % + 5 (89 IV)
0.025 % + 10 (87 IV) 2 % + 80 0.6 % + 40 6 % + 40 3
DC V 5.0000 V 0.0001 V 0.025 % + 10 2 % + 80 0.5 % + 40
50.000 V 0.001 V 0.03 % + 3 2 % + 80 0.5 % + 40
500.00 V 0.01 V 0.1 % + 2 2 % + 80 0.5 % + 40 Not specified
1000.0 V 0.1 V 0.1 % + 2 2 % + 80 0.5 % + 40 Not specified
DC µA 500.00 µA 0.01 µA 0.25 % + 20 57 % + 10 7 % + 10 9 % + 40
5,000 µA0.1µA 0.25 % + 2 1 % + 10 0.75 % + 10 2 % + 40
DC mA 50.000 mA 0.001 mA 0.15 % + 10 1 % + 10 0.75 % + 10 2 % + 40
400.00 mA 10.01 mA 0.15 % + 2 1.5 % + 10 1.5 % + 10 3 % + 40
DC A 5.0000 A 0.0001 A 0.5 %+ 10 7 % + 20 7 % + 20 12 % + 40
10.000 A 20.001 A 0.5 %+ 2 1.5 % + 10 1.5 % + 10 3 % + 40
1. mA for 30 seconds maximum.
2. 20 A overload for 30 seconds maximum.
3. DC 5 V range, -3 dB typical @ 10 kHz.
4. In RF field of 3 V/m, add 100 counts from 100 to 120 MHz, 60 counts from 270 to 300 MHz, 40 counts from 320 to 335
MHz.
5. In RF field of 3 V/m, add 500 counts from 80 to 95 Mhz.
6. See AC conversions notes for AC mV and V.

87 & 89 Series IV
Service Manual
8
Resistance and Conductance Specifications
Function Range Resolution Accuracy
Resistance 1500.00 Ω0.01 Ω0.05 % + 10 3, 4
5.0000 kΩ0.0001 kΩ0.05 % + 2
50.000 kΩ0.001 kΩ0.05 % + 2
500.00 kΩ0.01 kΩ0.05 % + 2
5.0000 MΩ0.0001 MΩ0.15 % + 4 2
30.000 MΩ0.001 MΩ1 % + 4 2
Conductance 50.00 nS 0.01 nS 1 % + 10
1. For the 5,000 count mode, divide the number of least significant digits (counts) by 10.
2. For relative humidity greater than 70 %, resistance accuracy is 0.5 % over 1 MΩand 2.5 % over 10 MΩ.
3. In RF field of 3 V/m, add 45 counts from 470 to 1000 MHz.
4. Using Relative Mode (REL) to zero residual reading.
Capacitance and Diode Function Specifications
Function Ranges Resolution Accuracy
Capacitance 11.100 nF 0.001 nF
11.00 nF 0.01 nF
110.0 nF 0.1 nF
1.100 µF 0.001 µF
11.00 µF 0.01 µF1%+5
110.0 µF0.1µF
1,100 µF1µF
11.0 mF 0.01 mF
50.00 mF 0.01 mF
Diode Test 23.1000 V 0.0001 V 2 % + 2
1. For film capacitor or better, using Relative mode (REL ∆) to zero residual on 1.1 nF range.
2. For the 5,000-count mode, divide the number of least significant digits (counts) by 10.
Frequency, Duty Cycle, & Pulse Width Specifications
Function Range Resolution Accuracy
Frequency 500.00 Hz 0.01 Hz 1±(0.005 % + 1)
5.0000 kHz 0.0001 kHz
50.000 kHz 0.001 kHz
999.99 kHz 0.01 kHz
Duty Cycle 210 to 90 % 0.1 % ±(0.12 x voltage range / input voltage x 100 %)
Pulse Width 25.0000 ms 0.0001 ms ±(0.0001 ms + 1)
50.000 ms 0.001 ms
1. Reading will be 0.00 for signals below 0.5 Hz.
2. Duty cycle and pulse width operate on repetitive waveforms at 14.5 Hz or greater.

Specifications
9
Temperature Specifications
−200 to +1350 °C0.1°C±( 1% of reading + 1 °C) 1, 2 Temperature
−328 to +2462 °F0.1°F±( 1% of reading + 1.8 °F) 1, 2
1. Accuracy specification is relative to the user-adjustable temperature offset, and assumes ambient temperature
stable to ±1 °C.
2. For ambient temperature changes of ±5 °C, rated accuracy applies after 1 hour.
MIN MAX Recording Specifications
MIN MAX AVG Response: 100 ms to 80 % Specified accuracy ±12 counts for changes >
200 ms in duration. (±40 counts in AC for
changes > 350 ms and inputs > 25 % of range)
FAST MN MX 250 µsSpecified accuracy ±100 counts for changes
>250 µs in duration 1
1. For repetitive peaks; 2.5 ms for single events.
Frequency Counter Sensitivity
Minimum Sensitivity (RMS Sine Wave) 1
Input Range 40 Hz to 20 kHz 215 to 40 Hz 320 to 500 kHz 3
Approximate Trigger
Levels
(DC Voltage Function)
50 mV (dB only) 15 mV to 3 mV 15 mV 15 mV ±25 mV
500 mV 50 mV to 30 mV 50 mV 30 mV 35 mV ±6 mV
3000 mV 1500 mV to 300 mV 2000 mV 2000 mV 170 mV ±6 mV
5 V 1.5 V to 0.3 V 2 V 2.2 V 1.7 V ±0.25 V
50 V 15 V to 3 V 15 V 5 V 3.5 V ±2.5 V
500 V 50 V to 20 V 50 V 50 V 35 V ±25 V
1000 V 250 V to 100 V 250 V 50 V 35 V ±25 V
1. Maximum input for specified accuracy = 10 x Range or 1000 V, ac-coupled only. Accuracy: add 1 count
2. Sensitivity improves linearly from 40 Hz to 20 kHz.
3. Useable at reduced sensitivity to 0.5 Hz and 999.99 kHz.

87 & 89 Series IV
Service Manual
10
Burden Voltage (A, mA, µ A)
Function Range Burden Voltage (typical)
mA - µA 500.00 µA 102 µV / µA
5,000 µA 102 µV / µA
50.000 mA 1.8 mV / mA
400.00 mA 1.8 mV / mA
A 5.0000 A 0.04 V / A
10.000 A 0.04 V / A
Input Characteristics
Function Input Impedance (Nominal)
Volts, mV 10 MΩ, < 100 pF
Common Mode Rejection Ratio Normal Mode Rejection
DC Volts, mV >100 dB -dc, 50 Hz, or 60 Hz ±0.1% >90 dB at 50 Hz, or 60 Hz ±0.1%
AC Volts, mV > 90 dB dc to 60 Hz
Full-Scale Voltage
Open Circuit Test Voltage To 5 MΩ30 MΩ+ nS
Ohms < 5 V 500 mV 3.1 V
Diode Test < 5 V 3.1000 V
Typical Short-Circuit Current
500 Ω5 kΩ50 kΩ500 kΩ5 MΩ30 MΩ
Ohms 100 µA100 µA10 µA1µA0.1 µA0.1 µA
Diode Test 0.8 mA typical

Required Equipment
11
Required Equipment
Required equipment is listed in Table 2. If the recommended models are not available,
equipment with equivalent specifications may be used.
Repairs or servicing should be performed only by qualified personnel.
Table 2. Required Equipment
Equipment Required Characteristics Recommended Model
Calibrator AC Voltage Range: 0-1000 Vac
Accuracy: + 0.1 %
Frequency Range: 20 Hz – 100 kHz
Accuracy: +3 %
DC Voltage Range: 0-1000 Vdc
Accuracy: + 0.006 %
Current Range: 0-10A
Accuracy: AC mA - +0.18 %
AC A - + 0.38 %
Frequency range: 1 kHz – 20 kHz
DC mA - + 0.06 %
DC A - + 0.125 %
Frequency Source: 0.5-20 kHz
Accuracy: + 0.00125 %
Amplitude: 1 Volt
Accuracy: + 5 %
Ohms Range: 0 Ω- 50 MΩ
Accuracy: + 0.0125 %
Capacitance Range: 110.0 nF & 11.00 uF
Accuracy: +0.25%
Temperature Range: -10 to 350 °C
Accuracy: 0.3%
Fluke 5520A
Thermocouple
Adapter Accessory K-type Fluke 80AK
K-type
Thermocouple K-type, mini-plug on both ends N/A
Infrared (IR) Adapter Fluke P/N 690518
87/89 IV Service
Software Fluke P/N 676152

87 & 89 Series IV
Service Manual
12
Basic Maintenance
Warning
To avoid electrical shock or personal injury, remove the test
leads and any input signals before opening the case or
replacing the battery or fuses. To prevent damage or injury,
install ONLY batteries or fuses specified for this product.
Opening the Meter Case
Caution
To avoid unintended circuit shorting, always place the
uncovered Meter assembly on a protective surface. When the
case of the Meter is open, circuit connections are exposed.
To open the Meter case, do the following:
1. Disconnect test leads from any live source, turn the rotary switch to OFF, and remove
the test leads from the front terminals.
2. Remove the battery door by using a flat-blade screwdriver to turn the battery door
fasteners 1/4-turn counterclockwise.
3. The case bottom is secured to the case top by four screws, one at each corner.
Remove the screws with a Phillips-head screwdriver.
4. Pull the two halves of the case apart.
Removing and Reinserting the Circuit Board Assembly
The circuit board assembly must be removed to access and replace the LCD.
Caution
The circuit board is extremely susceptible to contamination.
Handle it by the input receptacle, fuse clips or edges of the
board only. You can use clean surgical gloves to help avoid
contamination.
1. Open the Meter case and remove the case bottom to access the circuit board.
2. Remove the two Phillips-head screws securing the circuit board to the case top and
lift it out carefully to avoid contamination.
3. To reinsert the circuit board, simply place it into the case top with the LCD display
showing through the window.
4. Carefully replace the two Phillips-head screws that connect the circuit board to the
case top.
Caution
Do not over-torque the two Phillips-head screws when you
reconnect the circuit board to the case top. Doing so may
create shielding problems and cause the Meter to give incorrect
readings.