Fluke 27/FM User manual

27/FM
MULTIME TER
Operator's Manual
FLUKE
P/N 828558
AUGUST 1987
©1987. John Fluke Mfg. Co., Inc. All rights reserved. Litho in U.S.A.

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FLUKE 27/FM MULTIMETER OPERATOR'S MANUAL
CONTENTS
SECTION TITLE

PAGE
INTRODUCTION 
1
UNPACKING THE INSTRUMENT 
2
MULTIMETER SAFETY 
2
BATTERY INSTALLATION AND REPLACEMENT

3
GETTING STARTED QUICKLY

POWER-UP OPTIONS AND TESTS

5
OPERATING FEATURES 
5
MEASUREMENT TECHNIQUES AND CONSIDERATIONS

10
True RMS vs Average-Responding Meters

10
Measuring Voltage, AC/DC 
10
Measuring Current, AC/DC

12
Current Measurement Error Calculations
 12
Measuring Resistance 
13
Diode and Continuity Testing

13
Measuring Conductance

14
Leakage Testing

14
USING THE ANALOG BAR GRAPH 
15
Nulling 
15
Contact Bounce

15
Checking Capacitors 
16
Noisy Resistance Measurements

16
MAINTENANCE

16
General Maintenance 
16
Tilt Stand Adjustment

17
Fuse Test 
17
Fuse Replacement 
17
SPECIFICATIONS 
18
INTRODUCTION
The Fluke 27/FM Multimeter (hereinafter, also referred to as the "DMM" or
"meter") is a true rms, digital multimeter that provides unsurpassed
performance and operator safety in the most demanding working conditions. It
meets MIL-T-28800 Type II, Class 2, Style A specifications for shock,
vibration, humidity, and water resistance. The meter is powered by a 9V
battery with a life of 750 hours.
The Fluke 27/FM combines the precision of a digital meter with the speed and
versatility of an analog bar graph. Its 3200-count, digital display offers
better resolution than a conventional 3-1/2 digit, 2000-count display.
The 80K-6 High Voltage Probe that is shipped with the meter extends the
voltage measurement capability of the meter to 6000V. A 1000:1 voltage

Multimeter Safety
divider provides a high input impedance. Before using the 80K-6 probe, read
the instruction sheet that accompanies it.
UNPACKING THE INSTRUMENT
The meter is shipped with a 80K-6 high voltage probe (and instruction
sheet), TL70 test leads, two alligator clips (one red and one black), a 9V
alkaline battery, this operator's manual, and a protective carrying case for
meter and accessories. Contact the place of purchase immediately if anything
,
is missing or damaged.
When reshipping the meter, use the original container. If this container is
not available, we recommend that the instrument be surrounded by at least
three inches of shock-absorbing material in the shipping container.
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 possible hazard(s) to the operator; the word "CAUTION" means
damage to the meter may occur. The symbols shown in Figure 1 are used
internationally to denote the electrical functions and conditions indicated.
o Avoid working alone.
o
Inspect the test leads for damaged insulation or exposed metal.
Check test lead continuity. Damaged leads should be replaced.
o
Be sure the DMM is in good operating condition. During the
continuity test, a meter reading that goes from OL (overload) to 0
normally means the meter is working properly.
o
Select the proper function and range for your measurement.
o
A 101
When servicing, use only specified replacement parts.
OFF Ipower)
SWITCH
POSITION
VOLTAGE
DANGEROUS
I
ON Ipower)
SWITCH
POSITION
-I- —
_
GROUND
." - N ... „..
AC-
ALTERNATING
CURRENT
A SEE
EXPLANATION
 IN MANUAL
DC-
DIRECT CURRENT
DOUBLE
INSULATION
iProtection Class II)
•
- — —
EITHER
.-41.• FUSE
Figure 1. International Electrical Symbols

Battery Installation and Replacement
WARNING
TO AVOID ELECTRICAL SHOCK OR DAMAGE TO THE METER, DO NOT
APPLY MORE THAN 1000V BETWEEN ANY TERMINAL AND EARTH GROUND.
WARNING
TO AVOID ELECTRICAL SHOCK, USE CAUTION WHEN WORKING ABOVE
60V DC OR 25V AC RMS. SUCH VOLTAGES POSE A SHOCK HAZARD.
o
Disconnect the live (hot) test lead before disconnecting the common
test lead.
o
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
 and Ho , 4* functions.
o When making a current measurement, turn the power off before
connecting the'DMM in the circuit.
o
Check DMM fuses before measuring transformer secondary or motor
winding current. An open fuse may allow high voltage build-up,
which is potentially hazardous.
WARNING
TO AVOID ELECTRICAL SHOCK, REMOVE THE TEST LEADS AND ANY
INPUT SIGNALS BEFORE REPLACING THE BATTERY OR FUSES.
BATTERY INSTALLATION AND REPLACEMENT
The meter is powered by a single 9V battery (NEDA 1604, 6F22, or 006P).
Referring to Figure 2, use the following procedure to install (and replace)
the battery.
1.
Disconnect test leads from any live source, turn the rotary switch
to OFF, and remove the test leads from the input terminals.
2. Lift the instrument stand on the back of the Fluke 27/FM, then
remove the four (#6 X 32) screws from the battery cover.
3.
Pull the battery cover straight out from the back of the meter.
(A coin-slot in the side of the battery cover facilitates removal.)
4
•

Snap the battery connector to the terminals on the battery, then
slide the battery into the battery holder. Slip each battery lead
into the slot in the holder as shown in Figure 2.
5. 
Insert the battery holder/cover into the meter, then start the four
screws removed in step 2. Press firmly on the battery cover while
tightening the screws in a diagonal pattern.

Getting started Quickly
Figure 2. Battery Installation and Replacement
GETTING STARTED QUICKLY
NOTE
Read "MULTIMETER SAFETY" (above) before using the DMM.
Familiarize yourself with the layout of the meter, taking note of the
location of the input terminals, rotary switch, push buttons and display.
After doing so, you probably already have a good idea how to use the meter
to take basic voltage, current, and resistance measurements. Simply:
1. Insert the test leads in the appropriate input terminals, and set
the rotary switch to the desired position.
2.
To select additional functions and modes, press the appropriate
pushbuttons above the rotary switch.
o To operate the MIN/MAX and [manual] RANGE features: press to
select, press again to increment, and press and hold for two
seconds to exit.
o To operate the [Touch] HOLD and REL[ative] features: press to
activate and press again to exit.
An annunciator lights on the display to indicate that a function
has been selected.

Power-up Options and Tests
3. 
To take a measurement, make the proper contacts with the test lead
probes, inserting the meter in the circuit (in series for current
or in parallel for voltage measurements). Read the measurement on
the display. If you did not manually select a range (by using the
RANGE button), the range which provides the best resolution is
automatically selected for you.
This simple procedure will allow you to take basic measurements. However, to
use your meter to full advantage, read the remainder of this manual.
POWER-UP OPTIONS AND TESTS
To power up the meter, turn the rotary function selector switch from OFF to
any position. The meter then performs a selftest and battery check. During
the selftest all display segments are switched on for about 1 second, then
the display blanks. The meter is now operational.
The battery test performed at power up (and each time you select a different
function with the rotary switch) determines if the voltage is below 6.3V. If
it is, the C-2 annunciator comes on and remains on until the battery
recovers or is replaced (i.e, voltage is above the above the 6.3V.)
The meter powers up in the autorange mode. In autorange, the meter
automatically selects the appropriate range for the measurement being taken.
If the function selected has only one range, then the
ED
symbol is
displayed. The operating range is indicated by the decimal point position
and range indicator in the display, and in the
n
function by the presence
of the M or k annunciators. There is no annunciator for the autorange mode.
The meter is in autorange unless the manual range annunciator is on.
Manual ranging can be selected at power up by pressing and holding the RANGE
button while the function switch is moved from OFF to any ON position. To
return to the autorange mode, press RANGE for approximately two seconds.
If the HOLD push button is pressed while the function switch is moved from
OFF to any ON position, automatic updates in the Touch-Hold* mode are
defeated and the Touch-Hold mode only displays a new reading when HOLD
button is pressed. This is useful when you want to take a reading at a
specific time and hold it.
OPERATING FEATURES
The meter is operated from the front panel. All operating features and
functions are described below and are keyed by number to the illustration
inside the front cover.
(DDigital Display:
3200-count, liquid crystal display (LCD) with automatic decimal point
positioning. Updated two times per second. When the meter is first
turned on, all display segments appear while the instrument performs a
brief power-up self-test.
* Touch-Hold is a trademark of the John Fluke Manufacturing Co., Inc.

Function Selection
0
Function Selector Rotary Switch:
To select one of ten functions (or OFF), listed below, turn the function
selector rotary switch to the position for the desired function. Refer
to Table 1 for input terminals and limits and to specifications in Table
3 for available ranges.
V 
Volts dc
mV

Millivolts dc
V 
Volts ac
rn1/ 
Millivolts ac
Ohms (resistance), also conductance (1/ohms) in nanosiemens (nS)
(W
1-1
+ 
Continuity or diode test
rnAJA

Milliamps or amperes ac
pA 
Microamps dc
nIAJA

Milliamps or amperes dc
pA 
Microamps ac
Table 1. Input Terminals and Limits
FUNCTION
INPUT TERMINALS
Red Lead 
Black Lead
MIN DISPLAY
READING
MAX DISPLAY
READING
MAXIMUM
INPUT
=
V 
V V f) -ol- 
COM
0.001V
1000V
1000V
=  .--
mV 
mV
V 0 -41÷ 
COM
0.1
mV
320.0 mV
500V
0
(nS)
V f) -I+

COM
V 0
44-

COM
o.in
0.01 nS
32.00 MD
32.00 nS
500V
500V
Wo 44-
V r2 44-

COM
0.001V 2.08V 500V
,
m - ZA 
mA/A
A 
COM
0.01A 20.00A*
10A* 
600V
mA 
COM
pA
0.01 mA 320.0 mA
320 mA
 600V
pA  pA
mA
/./A 
COM
0.1 pA 3200 pA
320 mA
** 600V **
*
10A continous,
20A for 30 seconds maximum
"320mA continous, 1A for 30 seconds maximum
-6-

Input Terminals and Operating Modes
(2) 
Volt, Ohms, Diode Test Input Terminal:
Input terminal used in conjunction with the volts, mV (ac or dc), ohms,
or diode test position of the function selector rotary switch.
0
COM 
Common Terminal:
Common or return terminal used for all measurements.
0mA
pA 
Milliamp/Microamp Input Terminal:
Input terminal used for current measurements up to 320 mA (ac or dc)
with the function selector rotary switch in the mA or uA position.
0
A 
Amperes Input Terminal:
Input terminal used for current measurements up to 10A continuous (20A
for 30 seconds) with the function selector rotary switch in the mA/A
position (ac or dc)..
0
RANGE® 
Manual Range Mode Pushbutton:
Press once to enter manual range mode, press again to increment range,
press and hold for 2 seconds to return to autorange. Meter returns to
autorange if the function selector is switched to any other position.
There is no autorange annunciator; absence of the manual range
annunciator indicates the meter is in autorange. If RANGE is depressed
and held for the duration of the selftest, while the function switch is
moved from OFF to any ON position, manual ranging will be selected in
all functions.
0
RELA

Relative Mode Pushbutton:
Press momentarily to enter the Relative mode and store the displayed
reading. The display will read zero. Press again to update the stored
digital reading. Press and hold for 2 seconds to exit the Relative mode.
The Relative mode stores a digital reading and displays the change
(difference) between the stored reading and any following reading. For
example, if the stored reading is 15.00V and the present reading is
14.10V, the display will indicate -0.90V. The analog bar graph continues
to display the actual reading (14.10V). If the difference exceeds 3999
counts (without overloading the input), OF (overflow) is displayed. The
Relative mode selects manual ranging; changing ranges automatically
exits the Relative mode.
(::) MIN/MAX 
Mode Pushbutton:
Press momentarily to enter MIN/MAX mode, press again to toggle between
MIN and MAX indications. Press and hold for 2 seconds to exit MIN/MAX
mode. The meter stores the minimum and maximum digital readings, and
will display either reading as selected by the operator. Press the
HOLD/RESET button to reset the MIN/MAX readings to the present input.

Operating Modes and LCD Annunciators
The MIN/MAX mode selects manual ranging; use a range that can record the
maximum anticipated input. Range changes reset previously recorded
MIN/MAX readings. Exiting the MIN/MAX mode does not reset the previously
recorded readings unless the range or function is changed. The MIN/MAX
mode overrides the Touch-Hold mode.
0
HOLD EJ

Touch-Hold Mode Pushbutton:
Press momentarily to enter Touch-Hold mode. In Touch-Hold, the meter
captures a stable measurement and holds it on the display. The operator
can watch the probes while taking measurements in difficult or hazardous
circuits, then look at the display when convenient. The meter beeps and
the display is automatically updated each time a new, stable measurement
is made. Press momentarily to manually update reading. Press and hold
for 2 seconds to exit Touch-Hold mode. If HOLD is depressed and held for
the duration of the selftest, while the function switch is moved from
OFF to any ON position, the Touch-Hold mode will only update to a new
reading when the HOLD button is pressed. (Automatic Touch-Hold updates
are defeated.) This is useful when you want to take a reading at a
specific time and hold it.
0
MIN 
Minimum Value Annunciator:
Indicates that the meter is in the MIN/MAX recording mode, and the value
displayed is the minimum digital reading taken since reset or since
entering MIN/MAX. Refer to item
9
for operation.
(2) MAX 
Maximum Value Annunciator:
Indicates that the meter is in the MIN/MAX recording mode, and the value
displayed is the maximum digital reading taken since reset or since
entering MIN/MAX. Refer to item
9 for operation.
® A

Relative Value Annunciator:
Indicates that the meter is in the Relative mode and that the value
displayed is relative (the difference between the present measurement
and the previously stored reading). Refer to item 8 for operation.
Touch-Hold Mode Annunciator:
Displayed when the Touch-Hold mode is in use. Refer to item 10 for
operation.
0
Mkt') 
Resistance Annunciators:
The appropriate annunciator (M, k, or
n )
is displayed for the
resistance range in use.

LCD Annunciators
0
nS  Conductance Range Annunciator
(nS):
Top range of the resistance function is the conductance range. Displays
conductance in nS (nanosiemens). 1000/nS converts to Mfl
. (Example:
2 nS converts to 500BAO.) Use for measuring resistance above
32AAn .
Select n , open test leads, press RANGE button twice. (Refer to item
7
for manual range operation.)

. 1. Analog Bar Graph Display:
Analog representation of input. Composed of 31 segments which illuminate
starting from the left as the input increases. (See display inside front
cover.) A minus sign (INA
■
) is displayed for reverse-polarity inputs.
Updated 25 times per second.
C) I • I I I
3  30 
300
Decimal Point/Range Indicator:
Decimal point position and the digits (3, 30, 300) under the decimal
point indicate the range in use.
Manual Range Annunciator:
Displayed in the Manual Range mode or if the selected function has only
one range. Absence of the indicator implies autorange mode in use. The
meter powers-up in autorange. In autorange, the meter automatically
selects the measurement range. Refer to item
7 for operation.
0 n

Low Battery Annunciator:
At least 40 hours of battery life remain when first displayed. Battery
voltage is tested each time the function switch is moved to a new
position.
Negative Polarity Annunciator:
Automatically indicates negative inputs.

o
t.

Overload Indication:
Indicates that the input is too large for the input circuitry. (The
location of the decimal point depends on the measurement range.)

® OF 
Overflow Indication:
Indicates that the calculated difference in the Relative mode is too
large to display (>3999 counts) and that the input is not overloaded.
q
)Beeper (not illustrated):
The beeper emits beeps, clicks, or a continuous tone. It is used for
audible indication in the diode test mode, when operating the push
buttons, and when a new reading is displayed in the Touch-Hold mode.

True RMS and Measuring Voltage
MEASUREMENT TECHNIQUES AND CONSIDERATIONS
The following measurement techniques and considerations will assist you in
using your meter safely and effectively.
True RMS vs Average-Responding Meters
One of the most useful features of the Fluke 27/FM is the direct measurement
of true rms or effective ac voltages and ac currents. Mathematically, rms is
defined as the square root of the sum of the squares of the ac and dc
components. In physical terms, rms is equivalent to the dc value that
dissipates the same amount of heat in a resistor as the original waveform.
The reason that rms is valuable is that it greatly simplifies the analysis
of complex ac signals. Since rms is the dc equivalent to the original waveform,
it can be used in the relationships derived from Ohm's law (E = I x R), and
it provides a reliable basis for comparing dissimilar waveforms.
Most meters today have average-responding ac converters rather than true rms
ac converters. Usually the gain in average-responding meters is adjusted so
that the reading gives the rms value, provided the input signal is a
harmonic-free sinusoid. However, if the signal is not sinusoidal, the
average-responding meter does not give correct rms readings.
The Fluke 27/FM actually calculates the rms value through analog computation.
This means that readings are accurate rms values not only for harmonic-free
sinusoids, but also for mixed frequencies, modulated signals, square waves,
sawtooths, 10%-duty-cycle rectangular pulses, etc.
Figure 3
shows some common waveforms and a comparison of the readings
displayed by your true rms meter and average-responding meters. Figure
3
also illustrates the relationship between ac and dc measurements for
ac-coupled meters. For example, consider the first waveform, a 1.414V (0-pk)
sine wave. Both true rms and the rms-calibrated average-respondings meters
display the correct rms reading of 1.000V (the dc component equals 0).
However, consider the 1.414V (0-pk) rectified square wave. Both types of
meters correctly measure the de component (0.707V). Only the true rms meter
correctly measures the ac component (0.707V). The average-responding meter
measures 0.785V, which amounts to a 5.6% error in the total rms measurement
calculated from the ac and dc components. Since average-responding meters
have been in use for so long, you may have accumulated test or reference
data based on them. The conversion factors in Figure
3
should help you
convert between the two measurement methods.
Measuring Voltage, AC/DC
The multimeter features five ac voltage ranges and five dc voltage ranges.
All
ranges present an input impedance of approximately 10 megohms in
parallel with less than 100 pF. Measurement errors, due to circuit loading,
can result when making either ac or dc voltage measurements on circuits with
high source resistance. However, in most cases the error is negligible (0.1%
or less) if the measurement circuit source resistance is 10 kilohms or less.
If circuit loading does present a problem, the percentage of error can be
calculated using the appropriate formula from Figure 4.

Measuring Voltage
AQCOUPLED
INPUT
WAVEFORM
PEAK VOLTAGES METERED VOLTAGES
DC AND AC
TOTAL RMS
PK-PK
0-PK
AC COMPONENT ONLY
DC
COMPONENT
ONLY
R MS CAL* 27/FM TRUE RMS
=
Vac 2 + dc 2
SINE
PK
2.828
1.414
1.000 1.000
0.000
1.000
0

PK-PK
--f-
RECTIFIED SINE
(FULL WAVE)
PK

i_
-
1.414 1.414
0.421
0.435
0.900
1.000
o
ry)PK-PK
" -- f -
RECTIFIED SINE
(HALF WAVE)
PK
--i-
2.000 2.000
0.764
0.771
0.636
1.000
ni\PK-PK
0
T-
SQUARE
PK
art
-+---
PK-PK
-±.-
2.000
1.000 1.110 1.000
0.000
1.000
RECTIFIED
SQUARE
PK

PK-PK-+
0
T
1.414
1.414
0.785
0.707
0.707 1.000
RECTANGULAR
PULSE
2.000 2.000
2.22K
2K
90
2-VF
X
PK -PK
_ 4.1 0 y  14 _ 
4-
D = X/Y
K =OD - D 2
TRIANGLE
SAWTOOTH
PK
3.464
1.732
0
Av
1.000
0.960
0.000
1.000
PK-PK
i-
"
RMS CAL IS THE DISPLAYED VALUE FOR AVERAGE RESPONDING METERS
THAT ARE CALIBRATED TO DISPLAY RMS FOR SINE WAVES
Figure 1, Waveform Conversion

I DC VOLTAGE MEASUREMENTS
Loading Error in
0
/0 - 100 x Rs+ (Rs + IC)
Where: As

Source resistance in ohms of circuit
being measured.
2 AC VOLTAGE MEASUREMENTS
First, determine input impedance, as follows.
10 7
v /7 1 7 72 -
x - F. R
M.0) 2
Where Zin = effective input impedance
Rin 10Iohms
Cm • 100 x 10
-12 Farads
F = frequency in Hz
Then, determine source loading error as follows:
(vector algebra required)
100 x Zs
Loading Error in
% - 
Rs - Zin
Where: Zs = source impedance
Zin -- input impedance (calculated)
Rs = source resistance
Z in
Measuring Current
Figure 4.
Voltage Measurement Error Calculations
When measuring voltages above 320V in Touch-Hold mode, use manual ranging to
minimize readings of stray voltages.
Measuring Current, AC/DC
WARNING
INSTRUMENT DAMAGE AND OPERATOR INJURY MAY RESULT
IF THE FUSE BLOWS WHILE CURRENT IS BEING MEASURED
IN A CIRCUIT WHICH EXHIBITS AN OPEN CIRCUIT VOLTAGE
GREATER THAN 600V. DO NOT ATTEMPT AN IN-CIRCUIT
CURRENT MEASUREMENT WHERE THE POTENTIAL IS GREATER
THAN 600V.
The multimeter features five ac current ranges and five dc current ranges.
All current ranges are fuse protected. If a fuse opens, refer to the fuse
replacement procedures in the "MAINTENANCE" section of this manual.
Current Measurement Error Calculations
In an ac or de current measurement, the voltage developed across the meter's
terminals is called burden voltage. The burden voltage for a full-scale
input is given for each range in Table 3 (specifications). The burden
voltage can affect the accuracy of a current measurement if the current
source is unregulated and the terminal resistance represents a significant
portion (1/1000 or more) of the source resistance. If burden voltage does
present a problem, the percentage of error can be calculated using the
-12-

114
Es = Source voltage
RL = Load resistance -1- Source resistance
Im = Measured current (display reading in mA)
Es = Burden voltage (calculated). i.e.. Display reading
expressed as a % of full-scale (100 x
READING ) times
FULL-SCALE
full-scale burden voltage for selected range. See Table:
TYPICAL
BURDEN VOLTAGE
320 pA
3200 pA
32 mA
320 mA
10A
Maximum current error due to Burden Voltage
Es
fl
Of

100 x

Es - Es
Es x I m
Es -Es
Example: Es = 15V, R
L
= 500,1m = 270 mA.
270
Es = 100 x
320
x 1.8 (from Table)
84.4% x 1.8 = 1.519V
1.519 
1.519
Error in % — 100

— 100 
= 11.3%
15 - 1.519 
13.481
Increase displayed current by 11.3% to obtain true current
Error in mA =
1
.
519 x 270 , 410 s_
30.41 mA
15- 1.519 
13.481
Increase displayed current by 30 mA to obtain true current.
RANGE
0.16V
1.6V
.18V
1.8V
0.5V
in mA
Resistance, Diode and Continuity Testing
formula in Figure 5. Approximate terminal resistances for the current ranges
are: 0.05 ohms for A, 5.5 ohms for mA, and 500 ohms for uA.
Figure 5. Current Measurement Error Calculations
Measuring Resistance
CAUTION
Turn test circuit power off and discharge all capacitors
before attempting in-circuit resistance measurements.
The multimeter features six resistance ranges and a conductance range. All
ranges employ a two-wire measurement technique. As a result, test lead
resistance may influence measurement accuracy on the 320-ohm range. To
determine the error, short the test leads together and read the lead
resistance. Correct the measurement by subtracting the lead resistance from
the measurement, or use the Relative (REL A) mode to zero the display. The
error is usually 0.1 to 0.2 ohms for a standard pair of test leads.
Some in-circuit resistance measurements can be made without removing diodes
and transistors from the circuit. The full-scale measurement voltage
produced on ranges below 32 megohms does not strongly forward bias silicon
diodes or transistor junctions. Use the highest range you can (except 32
megohm) to minimize the possibility of turning on diodes or transistor
junctions. Full scale measurement voltage in the 32-megohm range does
strongly forward bias a diode or transistor.
Diode and Continuity Testing
In diode test, there is only one range: 0 to +2.08 volts. Voltage is
developed across the component(s) under test by a test current output from
-13-

Conductance and Leakage Testing
the multimeter. Voltages greater than 2.08V or open test leads produce an
overload (OL) condition. Negative inputs produce a negative indication (they
are not suppressed). In the diode test function ( ((to

), the beeper
produces a continuous tone if the input is less than 0.1V, and the beeper
beeps once when the input descends through a 0.7V threshold.
Audible continuity testing is also performed with the function selector
switch in the ( 
)
position. A continuous tone sounds for resistances
below approximately 150 ohms. An intermittent connection produces erratic
beeps, and can be a valuable troubleshooting aid. Erratic beeps can also
occur, due to environmental noise, if a test value is very close to the
threshold (150 ohms). Test resistances from approximately 150 ohms to 1000
ohms produce a short tone similar to a forward biased diode. Test
resistances less than approximately 20 kilohms will produce an on-scale
reading.
Measuring Conductance
Measuring conductance is performed with the function selector switch in
the ohms
(11)
function. The conductance range can only be entered when the
meter is in the manual ranging mode. The conductance range can be used both
to measure conductance (1/ohms, the inverse of resistance) and to measure
very high resistances (greater than 32 megohms).
High value resistance measurements are susceptible to induced noise, and may
require careful shielding. Conductance measurements are displayed in
nanosiemens (nS). Calculate megohms by dividing 1000 by the nanosiemens
displayed (1000/nS is equivalent to megohms). Example: 2 nS converts to 500
megohms (1000/2).
Leakage Testing
The conductance range effectively extends the resistance measurement
capability of the multimeter to the point where it can provide useful leakage
measurements on passive components. For example, the operator can detect
leaky diodes, cables, connectors, printed circuit boards, etc. In all cases,
the test voltage is less than 2V dc.
Leakage testing on purely resistive components such as cables and printed
circuit boards is straightforward. Select the ohms function and manually
increment the range to conductance (nS). Connect the test leads to the test
points on the unit under test, and read the leakage in terms of conductance.
NOTE
In the conductance range, there is normally a small
residual reading with open test leads. To ensure accurate
measurements, connect clean test leads to the multimeter
and (with the leads open) read the residual leakage in
nanosiemens. Correct subsequent measurements by
subtracting the residual from the readings. This can be
done automatically using the Relative mode (REL

).

Using the Bar Graph
Diode leakage tests require that the diode junction be reverse biased when
being measured. This is accomplished by connecting the anode of the diode
to the COMMON input terminal and the cathode (ring) of the diode to the
V
ri 
input terminal. Leakage at the test voltage being applied can
then be read in terms of conductance.
High-voltage stacked diode assemblies can usually be tested for forward and
reverse resistance changes using conductance. These assemblies typically
have such high forward voltage drops that the diode test or resistance modes
cannot test them.
USING THE ANALOG BAR GRAPH
The analog bar graph functions like the needle on an analog meter without
the mechanical overshoot of movements.
The bar graph is especially useful for peaking and nulling, and observing
rapidly changing inputs. Because bar graph response time is fast and
precise, it can be used to make approximate adjustments quickly. The
3200-count digital display can then be used for final adjustment.
The analog bar graph can also be used for some limited diagnostic purposes.
In situations where rapidly fluctuating signal levels make the digital
display useless, the bar graph is ideal. Like the needle on a Volt-ohm
milliammeter (VOM), the analog bar graph excels at displaying trends, or
slowly changing signals. In addition, in the Autorange mode, you can monitor
signal change through changing ranges. Many diagnostic routines using the
bar graph require practice. You will usually be looking for good or bad
signal patterns that occur over some span of time. Noisy resistance
measurements, for instance, create such patterns. Therefore, familiarity
with analog bar graph response and movement is necessary to accurately
interpret a signal pattern. Compare the bar graph response when making
measurements on a known-good unit to the bar graph response when making
measurements on a faulty unit.
Nulling
The DMM's bar graph is ideal for nulling adjustments. As an adjustment
approaches zero, fewer bar graph segments are displayed, until no bar graph
segments are displayed. The ow annunciator flickers when the input level is
within 10 counts of zero. The flickering null indication is displayed every
time the input approaches zero or swings from one polarity to the other.
Watch for the 
annunciator indication, then reverse the direction of the
adjustment when the polarity sign is displayed. In one or two passes, a
near-zero input level is possible, then the digital display can be used for
exact zero adjustment.
Contact Bounce
Relay contacts may begin to bounce open when subject to vibration. Testing
for this problem is a routine troubleshooting practice for many types of
equipment. Since the bounce problem will worsen as 'the relay fatigues, early
diagnosis is important.

Using the Bar Graph
The bar graph will display at least one segment when the contact opens. The
bar graph can detect contact bounce as brief as 0.2 ms, while most analog
needle movements require a
3 ms opening before they will respond.
Checking Capacitors
With the meter set to the resistance function, the analog bar graph can be
used (even in the autoranging mode) to check capacitors. As a capacitor is
placed across the inputs, the analog bar graph quickly shortens, then
rapidly down-ranges, depending on the size of the capacitor. As the
capacitor charges, the bar graph slowly extends back to its full 31-segment
length, up-ranging if necessary. For capacitors as small as 0.02 uF, only
the 30-megohm range is involved, the last few segments blink off, then back on.
In a fixed range (using manual range mode), the time it takes for the bar
graph to extend from zero to full scale indicates the approximate
capacitance value. Table 2 gives typical capacitance values for various
charge times on different resistance ranges. For very small capacitors, use
the conductance (1/ohm nS) mode.
Table 2. Capacitance vs. Time to Full Scale
Resistance
Range
3200
3.2k0
32k0
320k0
3.2M0
32M0
Capacitance
Value
10,000 pF
1,000 pF
100 pF
10 pF
1 pF
0.1 pF
0.02 pF
4 sec
blink
nil
nil
nil
nil
nil
8
co C =

=
-c)
E
(
i
)
i
n
8
Nt
ext
ext
32 sec
4 sec
blink
nil
nil
ext
ext
ext
30 sec
3 sec
blink
nil
ext
ext
ext
ext
19 sec
2 sec
blink
ext = extended time, nil = no indication
Noisy Resistance Measurements
Your Fluke meter will tolerate ac noise far better than the usual DMM.
Readings of 2-kilohms can be obtained even in the presence of 1V ac noise.
Readings of 1 megohm may be obtained with up to 2V ac noise. The noise
appears as about 50 counts of change and an oscillating bar graph.
MAINTENANCE
General Maintenance
Replaceable parts are listed below:
PART 
FSCM  PART NO.  NSN
F1-Fuse, Catridge 1A/600V

71400

BBS-1  5920-00-615-3781
F3-Fuse 15A/600V  71400 
KTK-15 
5920-00-064-2374
Lead, Test 
89536
 654053

6625-01-220-5608
Battery, 9V Alkaline,
NEDA 1604A

Fuse Test and Replacement
Clean the case with a damp cloth and detergent; do not use abrasives or
solvents.
Have the meter calibrated by a qualified technician once a year to
ensure specified performance.
Tilt Stand Adjustment
To use the tilt stand as a handle, lift the stand slightly (about 1 inch or
2.5 cm), pull the ends out, and insert the ends in the alternate set of holes.
Fuse Test
Use the following procedure to test internal fuses:
1.
Turn the function selector switch to the
n
position.
2. Connect a test lead from the V
n 44-
input terminal to the A input
terminal.
3.
The display should indicate between 0.1 ohm and 0.3 ohm. This tests
F3 (15A, 600V fast).
4.
Move one end of the test lead from the A input terminal to the
mA/uA input terminal.
5.
The display should indicate between 4.5 ohms and 6.5 ohms. This
tests F1 (1A, 600V fast).
6.
If either of the above display indications is OL (overload),
replace the appropriate fuse.
Fuse Replacement
WARNING
TO PREVENT DAMAGE OR INJURY, REPLACE A FUSE WITH ONE OF
THE SAME SIZE AND AMP/VOLT RATINGS.
Use the following procedure to check or replace the multimeter's fuses.
(Refer to Figure 2, if necessary).
1.
Perform steps 1 through
3
of the battery installation and
replacement procedure.
2.
Remove the defective fuse (or check continuity through the
suspected fuse).
3.
Replace the defective fuse(s) with a new fuse of the same size and
rating.
4
•

Reinstall the battery cover/holder as described in step
5
of the
battery installation and replacement procedure.

Specifications
SPECIFICATIONS
Table 3.
Specifications
FUNCTION RANGE
RESOLUTION ACCURACY'
3.200V
32.00V
320.0V
1000V
0.001V
0.01V
0.1V
1V
+/-(0.1%+1)
+/ - (0.1%+1)
+/ - (0.1%+1)
+/-(0.
1
%+1)
mV 320.0 mV 0.1 mV
+/ -
(0.1%+1)
320.00 0.10
3.200 kcl 0.001 Ic0
+/-(0.25%+1)
32.00 1(0 0.01 kla
+1-(0.25%+1)
320 . o 0.1  Ida
+/-(0.25%+1)
3.200 MO
0.001 MO
+/-(0.25%+1)
32.00 MO
0.01 MO
+/-(1%+1)
(nS)
32.00 nS 0.01 nS
+/-(2%+10) typical
Vw
41-
2.000V 0.001V +/-(1%+1) typical
For continuity tests, the beeper emits a continuous tone at
test resistance below approximately 1500
20 Hz-40 Hz
 40 Hz-1 kHz 1 kHz-5 kHz
3.200V
0.001V
+1-(1.5%+5) +/-(5%+5)
32.00V
0.01V
+/-(1.5%+5) +/-(0.5%+5)
320.0V 0.1V
+/-(1.5%+5) +1-(0.51+5)
+/-(51+5)
1000V 1V
+1-(1.5%+5)
rat 320.0 mV
0.1 
mV
+/-(1.5%+5) +/-(0.5%+5) +/-(5%+5)
* Accuracy is specified as +/-C% of reading] + [number of least
significant digits]).
Basic electrical accuracy is specified from 18 to 28
° C, at a relative
humidity of up to 95%, for one year after calibration.
Within a single ac range, accuracy is specified between 5 and 100% of
full range. AC conversion method is AC coupled, true rms responding to
signals whose crest factor is 3:1 or less.