Fluke 87 TRUE RMS MULTIMETER User manual

®
87
True RMS Multimeter
Users Manual
PN 834192
August 1988 Rev.8, 4/97
© 1988, 1989, 1990, 1992,1993, 1994, 1997 Fluke Corporation. All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies.

Interference Information
This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with
the manufacturer’s instructions, may cause interference to radio and television reception. It has been type tested
and found to comply with the limits for a Class B computing device in accordance with the specifications of Part
15 of FCC Rules, which are designed to provide reasonable protection against such interference in a residential
installation.
Operation is subject to the following two conditions:
•This device may not cause harmful interference.
•This device must accept any interference received, including interference that may cause undesired opera-
tion.
There is no guarantee that interference will not occur in a particular installation. If this equipment does cause in-
terference to radio or television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one of more of the following measures:
•Reorient the receiving antenna
•Relocate the equipment with respect to the receiver
•Move the equipment away from the receiver
•Plug the equipment into a different outlet so that the computer and receiver are on different branch circuits
If necessary, the user should consult the dealer or an experienced radio/television technician for additional sug-
gestions. The user may find the following booklet prepared by the Federal Communications Commission helpful:
How to Identify and Resolve Radio-TV Interference Problems. This booklet is available from the U.S. Govern-
ment Printing Office, Washington, D.C. 20402. Stock No. 004-000-00345-4.
Fluke Coporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett, WA 98206-9090 5602 BD Eindhoven
U.S.A. The Netherlands

i
Table of Contents
Title Page
Introduction ....................................................................................................................1
Multimeter Safety ........................................................................................................... 2
Getting Started Quickly .................................................................................................. 3
How to Use the Meter..................................................................................................... 6
Input Terminals and Input Alert ................................................................................. 6
Pushbuttons............................................................................................................... 8
Summary of Power-On Options................................................................................. 13
Digital and Analog Displays....................................................................................... 13
Holster and Flex-Stand.............................................................................................. 17
Applications....................................................................................................................17
Measuring Voltage (AC/DC)...................................................................................... 19
Measuring Current..................................................................................................... 19
Continuity Testing...................................................................................................... 20
Measuring Resistance............................................................................................... 20
Using Conductance for High Resistance or Leakage Tests...................................... 21

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Noisy Resistance Measurements.............................................................................. 22
Measuring Capacitance ............................................................................................ 22
Diode Testing............................................................................................................ 23
Using the Analog Display.......................................................................................... 24
Using the MIN MAX Recording Mode....................................................................... 24
Measuring Frequency............................................................................................... 26
Measuring Duty Cycle............................................................................................... 27
Pulse Width Measurements...................................................................................... 29
Maintenance.................................................................................................................. 29
General Maintenance................................................................................................ 29
Calibration................................................................................................................. 30
Battery Replacement ................................................................................................ 30
Fuse Test W............................................................................................................. 30
Fuse Replacement W............................................................................................... 32
Service W................................................................................................................. 32
Replaceable Parts ......................................................................................................... 33
Specifications................................................................................................................. 36

iii
List of Tables
Table Title Page
1. International Electrical Symbols.......................................................................................... 3
2 Input Terminals and Limits..................................................................................................4
3. Beeper Response in Continuity Test..................................................................................7
4. Options Available at Power-on .........................................................................................14
5. Approximate Charge Rate for Capacitors......................................................................... 23
6. Frequency Counter Operation With Current Inputs..........................................................27
7. Replaceable Parts ............................................................................................................ 34

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v
List of Figures
Figure Title Page
1. Summary of Pushbutton Operation ....................................................................................9
2. Holster and Flex-Stand..................................................................................................... 18
3. Duty Cycle Measurement of Typical Logic Signal............................................................. 28
4. Battery and Fuse Replacement ........................................................................................ 31
5. Replaceable Parts ............................................................................................................ 35

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1
Introduction
Note
This meter has been designed and tested
according to IEC 1010-1, Safety Requirements
for Electrical Equipment for Measurements,
Control, and Laboratory Use. This manual
contains information and warnings which must be
followed to ensure safe operation and retain the
meter in safe condition. If the meter is not used
as described in this manual, the safety features
of the meter might be impaired.
Warning
Read "Multimeter Safety" before using the
meter.
The Fluke 87 True RMS Multimeter (also referred to as
"the meter") is a handheld, 4000-count instrument that is
designed for use in the field, laboratory, and at home. The
meter combines the precision of a digital meter with the
speed and versatility of a high resolution analog display.
Frequencies between 0.5 Hz and 200 kHz can be
measured with up to 0.01 Hz resolution. The meter is
powered by a 9V battery and has a rugged case sealed
against dirt, dust, and moisture. A snap-on holster, with
flexible stand (Flex-Stand), protects the meter from
rough handling. The flexible stand allows the meter to be
stood or hung.
The meter also provides:
•A MIN MAX Recording mode, in which the meter
"remembers" the lowest and highest readings,
calculates the true average of all readings taken over
a period as long as thirty-six hours, and displays
these values. The beeper emits a Min Max Alert
when a new minimum or maximum reading is
recorded.
•A Peak MIN MAX mode that captures changes as
short as 1 millisecond.
•An alternate Frequency Counter mode that measures
duty cycle and displays it as a value between 0.1 and
99.9%.
•An Input Alertthat causes the beeper to sound if the
test leads are plugged into the wrong input terminals
for the function being performed.
•A REL mode that allows you to store a reading in
memory, and display the difference between the
stored value and subsequent readings.

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•A Touch Holdmode that allows you to keep your
eyes fixed on the probes when taking measurements
in difficult or hazardous circumstances, then read the
display when it is convenient and safe.
•A display back-light that makes the meter useable in
dark areas.
•A 4 ½-digit display mode for a ten times increase in
resolution.
•A Capacitance mode that measures capacitors from
0.01 nF to 5 µF.
After unpacking the meter, if you notice that the meter is
damaged or something is missing, contact the place of
purchase immediately. Save the shipping container and
packing material in case you have to reship the meter.
Multimeter Safety
Before using the meter, read the following safety
information carefully. In this manual the word, "Warning,"
is reserved for conditions and actions that pose hazard(s)
to the user; the word, "Caution," is reserved for conditions
and actions that may damage your meter. The symbols
shown in Table 1 are used internationally to denote the
electrical functions and conditions indicated. If the meter is
not used as described in this manual, the safety features
of the meter might be impaired.
•Avoid working alone.
•Do not allow the meter to be used if it is damaged, or
it's safety is impaired.
•Inspect the test leads for damaged insulation or
exposed metal. Check test lead continuity. Damaged
leads should be replaced.
•Be sure the meter is in good operating condition.
During a continuity test, a meter reading that goes
from overload (OL) to 0 generally means the meter is
working properly.
•Select the proper function and range for your
measurement.
•In order to maintain the safety protection of this
meter, use only parts listed in the Service Manual.
Refer to Table 7 for the Service Manual part number.
•CAT III: For making measurements on equipment in
fixed installations (industrial).
Warning
To avoid electrical shock, use caution when
working above 60V dc or 30V ac rms. Such
voltages pose a shock hazard.

Getting Started Quickly
3
Table 1. International Electrical Symbols
BAC-Alternating
Current WSee Explanation in Manual
FDC-Direct
Current TDouble insulation (Protection Class II
CEither DC or AC IFuse
JGround
•Disconnect the live test lead before disconnecting the
common test lead.
•Follow all safety procedures for equipment being
tested. Disconnect the input power and discharge all
high-voltage capacitors through a protective
impedance before testing in the Ωand Lfunctions.
•When making a current measurement, turn the power
off before connecting the meter in the circuit.
•Check meter fuses before measuring current
transformer secondary or motor winding current. (See
"Fuse Test" in the "Maintenance" Section.) An open
fuse may allow high voltage build-up, which is
potentially hazardous.
Getting Started Quickly
Examine the meter carefully, familiarizing yourself with the
layout of the input terminals, rotary switch, pushbuttons
and display. Notice the Warning information and summary
of power-on options engraved into the rear panel.
If you have used a multimeter before, simply examining
your meter will probably give you a good idea how to use
it. The following procedure is an overview of how to take
basic measurements.
Warning
To avoid electrical shock or damage to the
meter, do not apply more than 1000V between
any terminal and earth ground.
1. Insert the test leads in the appropriate input terminals
(see Table 2). If the test leads are in the wrong input
terminals when the meter is turned on and the beeper
has not been disabled, the beeper will emit a
warning. See "Input Terminals and Input Alert",
below.

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Table 2. Input Terminals and Limits
Function Input Terminals MIN Display MAX Display Maximum Input
Red Lead Black Lead Reading † Reading
KzCOM 0.01 mV 1000V 1000V
LzCOM 0.0001V 1000V 1000V
lzCOM 0.01 mV 400.0 mV 1000V
e
nS
E
z
z
z
COM
COM
COM
0.01Ω
0.001 nS
0.01 nF
40.00 MΩ
40.00 nS
5.00 µF
1000V
1000V
1000V
GzCOM 0.0001V 3.000V 1000V
A CA COM 0.1 mA 20.00A* 11A 1000V Fast Fuse**
mA F
µA BmA/µA
mA/µACOM COM 0.001 mA 0.01 µA400.0 mA 4000 µA44/100A 1000V Fast Fuse**
* 10A continuous, 20A for 30 seconds maximum.
** Fuse protected.
† See the 4½ digit display mode on page 8.

Getting Started Quickly
5
2. To turn the meter on and select a function, turn the
rotary switch from OFF to the appropriate switch
position. All segments on the liquid-crystal display
(LCD) will turn on for one second, then the meter is
ready for normal operation. If you would like to freeze
the display with all segments on, press and hold
down any button, while turning the meter on. As long
as the button is held down, all LCD segments will
remain on.
3. To select an additional operation, press the
appropriate pushbuttons above the rotary switch as
described in the items below. (See also, Figure 1.)
•To operate the MIN MAX and RANGE buttons: press
to select, press again to scroll or increment, and
press and hold for two seconds to exit.
•To operate the Hz button: press to select the
frequency mode, press again to select duty cycle, and
press again to exit.
•To operate the back-lit display, press the YELLOW
button. The back-light automatically turns off in 68
seconds to conserve battery life.
•To operate the remaining buttons: press to select and
press again to exit.
Note
The response of the display and the pushbuttons
slows down in the capacitance mode.
An annunciator is displayed when a mode has been
selected. A quick way to reset all the pushbuttons to their
default state is to turn the rotary switch to an adjacent
function and then back to the function you are using.
4. To take a measurement, use the test lead probes to
make the proper contacts. Remember, insert the
meter in the circuit in parallel for voltage and in series
for current measurements. Read the measurement on
the display. If you did not manually select a range (by
using the RANGE button), the range that provides the
best resolution is automatically selected.
5. To run a performance check of the meter, turn the
rotary switch to Ωand connect a test lead from the
Tinput to the mA µA input. (If you are using a
test probe, touch the half of the input contact nearest
the LCD.) The display should read 1.000 kΩ±5
digits. With the rotary switch still at Ω, test the A fuse
(11A) by inserting the plug end of the test lead into
the A input and test the mA uA fuse (44/100A) by

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inserting the plug end of the test lead into the mA uA
input. The beeper emits an Input Alert if the fuses are
good.
Although this procedure will allow you to get started
quickly, we suggest that you take the time to read the
remainder of this manual so that you can learn to take full
advantage of your meter’s capabilities.
How to Use the Meter
This section describes your meter and how to use it. For
ease of reference, each description is numbered and
keyed to the illustration inside the front cover.
Input Terminals and Input Alert
Items 1-4 describe the input terminals. (See Table 1 for
overload limits.) If the test leads are connected to the
Amperes input terminal, and the function selector switch is
not in the Amp measurement position, the beeper will emit
an Input Alert. An Input Alert will also sound if the test
leads are connected to the mA uA terminal and the
function switch is not in either Amp position. After an Input
Alert sounds, the meter will attempt to take a reading from
inputs applied to the Tterminal. Input Alert can be
disabled by pressing Twhile turning the rotary
switch from OFF to any function position.
AA Amperes Input Terminal.
For current measurements (ac or dc) up to 10A
continuous (20A for 30 seconds) when function
selector switch is set to
^
\
BmA µA Milliamp/Microamp Input Terminal
For current measurements up to 400 mA (ac or dc)
when the function selector switch is set to ^ or
µAC
\
CCOM Common Terminal
Return terminal for all measurements.
DzVolts, Ohms, Diode Test Input Terminal
Function Selector Rotary Switch
EItem 5 describes functions that are selected by setting
the rotary switch. Each time the rotary switch is
moved from OFF to a function setting, all LCD
segments will turn on for one second as part of a
selftest routine. (This selftest routine is also
performed if the rotary switch is turned slowly from
one position to another.) The meter is then ready for
normal operations and will respond to the rotary
switch and pushbuttons.

How to Use the Meter
7
OFF
Power to the meter is turned off.
KVolts ac
Autoranges to the 400 mV, 4V, 40V, 400V or 1000V
range.
LVolts dc
Autoranges to the 4V, 40V, 400V or 1000V range.
lMillivolts dc
Single 400 mV range.
ReE Resistance (Ω), conductance (1/Ω),
capacitance or continuity Rtesting.
Press BLUE button to toggle between the resistance
and capacitance function. (The response of the
display and the pushbuttons slows down in the
capacitance mode.)
Autoranges to the 400Ω, 4 kΩ, 40 kΩ, 400 kΩ, 4 MΩ,
or 40 MΩresistance range.
In Manual Ranging mode, 40 nS conductance range
(equal to a 25-100,000 MΩrange) is selectable. (See
item 9.)
Autoranges to the 05.00 nF, .0500 µF, 0.500 µF, or
05.00 µF capacitance range.
When testing continuity, the beeper sounds if the
resistance falls below the typical values indicated in
Table 3.
Table 3. Beeper Response in Continuity Test
Input Range Beeper On If
400.0Ω
4.000 kΩ
40.00 kΩ
400.0 kΩ
4.000 MΩ
40.00 MΩ
<40Ω
<200Ω
<2 kΩ
<20 kΩ
<200 kΩ
<200 kΩ
LDiode Test
Measures forward voltage of semiconductor
junction(s) at approximately 0.5 mA test current.
Single 0-3V range.

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^Milliamps or amperes
\
Defaults to dc. Press BLUE button to toggle between
dc and ac.
Autoranges to the 40 mA or 400 mA range when
using the mA µA input terminal, or to the 4000 mA or
10A range when using the [A] input terminal.
µA CMicroamps
Defaults to dc. Press BLUE button to toggle between
dc and ac.
Autoranges to the 400 µA or 4000 µA range when
using the mA µA input terminal.
Pushbuttons
Items 6-13 describe how to use the pushbuttons. These
buttons are used (in conjunction with rotary switch) to
select operating modes and set power-on options. When a
button is pushed the beeper sounds (unless the beeper
has been turned off or the Data Output mode has been
selected). A summary of pushbutton operations is shown
in Figure 1. An annunciator is displayed to indicate that a
mode or option has been selected. A quick way to reset all
the pushbuttons to their default state is to turn the rotary
switch to an adjacent function and then back to the
function you are using.
FbDisplay Back-Light
Press the YELLOW button to turn on the back-light.
Back-light turns off automatically after 68 seconds to
extend battery life.
Power-On Option: 4½-Digit Display Mode
The meter displays the readings at 10 times the
resolution with a maximum display at 19,999 counts.
The display is updated once per second. The 4½-digit
display mode works in all functions except
capacitance, Peak MIN MAX and 100 millisecond
MIN MAX. Use manual ranging for best performance.
GAC or DC, Resistance or Capacitance
Press BLUE button to toggle between ac and dc
when measuring current, or between capacitance and
resistance when the rotary switch is set to ReE

How to Use the Meter
9
MIN MAX
REL Hz
RANGE HOLD
PEAK MIN MAX
H
_Press to Select
_Press again to Scroll or increment
_Press and Hold Down for 2 Seconds to Exit
_Press to Select Fequency
_Press again to Select Duty Cycle
_Press again to Exit
_Press to Select
_Press again to Exit
_Press to Turn on Back Light
_Turns Off Automatically After 68 Seconds
ep1f.eps
Figure 1. Summary of Pushbutton Operation

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Power-On Option: Disable Automatic Power-off
Automatic Power-off extends the life of the battery by
turning part of the meter off if neither the rotary switch
nor a pushbutton is operated for half an hour.
(Automatic Power-off is not allowed in the MIN MAX
Recording or Data Output modes.) The meter turns
back on if either the rotary switch is turned or a
pushbutton is pressed.
HMMinimum (MIN), Maximum (MAX),
Average (AVG) Recording
Press Mto enter the MIN MAX Recording mode
(manual range only). Select the proper range before
selecting MIN MAX to ensure that the MIN MAX
reading will not exceed the measurement range. The
minimum, maximum, and average values are then
reset to the present input; the RECORD annunciator
turns on; the AUTO annunciator turns off; and the
automatic power-off feature is disabled.
In the MIN MAX Recording mode, the minimum and
maximum readings are stored in memory. The beeper
emits a tone when a new minimum or maximum value
is recorded. A continuous beeper tone is emitted
when an overload is recorded. Push Mto cycle
through the maximum (MAX), minimum (MIN),
average (AVG), and present readings. The MIN,
MAX, or AVG annunciator turns on to indicate what
value is being displayed. If an overload is recorded,
the averaging function is stopped and the average
value becomes OL (overload).
The true average of all the readings taken over at
least a thirty-six hour period can be displayed. If this
duration is exceeded, the actual minimum and
maximum readings will continue to be captured and
can be displayed. However, new averages are no
longer calculated. The last average calculated is
retained as the average reading.
At normal (default) record speed, changes to the
voltage, current, or resistance inputs that last at least
100 milliseconds are recorded, and the "100 ms"
annunciator turns on. Press and hold down the
Mfor 2 seconds to exit and erase recorded
readings.
In the MIN MAX mode, press Tto select the
Peak MIN MAX mode ("1 ms", "RECORD", and
"MAX" are displayed). Voltage or current inputs that
last for 1 milliseconds or longer are captured. Press
Mto select the minimum (MIN) reading. Press

How to Use the Meter
11
again to return to the maximum (MAX) reading. To
reset the Peak MIN MAX mode press Ttwice:
the first press exits the mode, and the second press
re-enters the mode. To completely exit the MIN MAX
mode, press Mfor one second. In Peak MIN
MAX mode, the present reading, average (AVG)
readings, and analog display are not displayed.
Before selecting Peak MIN MAX, select DC voltage or
current to DC couple the input waveform; or AC
voltage to capacitively couple the input waveform.
Peak MIN MAX works in all functions except ohms,
frequency and capacitance.
In the MIN MAX Recording mode, press Ito
stop the recording of readings; press again to restart
recording. If recording is stopped, the minimum,
maximum, average, and present values are frozen,
but the analog display continues to be active. When
recording is stopped, the stored readings are not
erased and you can still scroll through these
readings.
Power-On Option: Select High Accuracy MIN
MAX Recording
The High Accuracy MIN MAX Recording mode has a
response time of approximately 1 second. Changes of
more than 1 second duration are recorded. The "1 s"
annunciator is turned on. In the Frequency Counter
mode, readings are always recorded at the high
accuracy recording speed; the response time is not
selectable.
IKManual Ranging
Press Kto select the Manual Range mode and
turn off the AUTO annunciator. (The meter remains in
the range it was in when manual ranging was
selected.)
In the Manual Range mode, each time you press
Kbutton, the range (and the input range
annunciator) increments, and a new value is
displayed. If you are already in the highest range, the
meter "wraps around" to the lowest range. (In the
Frequency Counter mode, pressing Kmanually
selects the input voltage or current range.) To exit the
Manual Range mode and return to autoranging,
Press and hold down Kfor 2 seconds. The
AUTO annunciator turns back on.
When the range is changed manually, the Touch
Hold, MIN MAX Recording, and REL[ative] modes are
disabled.

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Power-On Option: Rotary Switch Test
The Rotary Switch Test is used only for servicing
purposes. See the 80 Series Service Manual for
details. In the Rotary Switch Test mode, normal meter
functions are disabled. To exit the Rotary Switch
mode, turn the rotary switch to OFF and back to any
switch setting.
JIDisplay Hold
Warning
Touch hold will not capture unstable or noisy
readings. Do not use touch hold to determine
that circuits with dangerous voltage are dead.
Press Ito toggle in and out of the Touch Hold
mode, except if you are already in the MIN MAX
Recording or Frequency Counter mode.
In the Touch Hold mode, the Hannunciator is
displayed and the last reading is held on the display.
When a new, stable reading is detected, the beeper
emits a tone, and the display is automatically
updated. Pressing Mwhen you are in the Touch
Hold mode causes you to exit Touch Hold and enter
the MIN MAX Recording mode.
In the MIN MAX Recording mode, press Ito
stop the recording of readings; press Iagain to
resume recording. (Previously recorded readings are
not erased.)
In the Frequency Counter mode (Hz), press Ito
stop the display; press Iagain to start it.
KTContinuity Beeper/Peak MIN MAX
Press Tto toggle the beeper on or off for
continuity testing in the ohms function.
The beeper responds as indicated in Table 2.
In the Frequency Counter mode, press Tto
change the trigger slope from positive-going edges to
negative-going edges. The slope selected is indicated
by the analog display polarity annunciator (±).
In the MIN MAX mode, press Tto toggle in and
out of the Peak MIN MAX mode. See item 8.
Power-On Option: Disable Beeper
When the beeper has been disabled, all beeper
functions are turned off. The beeper is automatically
disabled if the meter is in the Data Output mode.