Fluke 28-II, 28-II-KIT3 User manual

27 II/28 II

Digital Multimeters

Users Manual

®

September 2009, Rev. 1, 10/10
© 2009, 2010 Fluke Corporation. All rights reserved. Specifications are subject to change without notice.
All product names are trademarks of their respective companies.

Lifetime Limited Warranty

Each Fluke 20, 70, 80, 170, 180 and 280 Series DMM will be free from defects in material and workmanship for its lifetime. As used herein,
“lifetime” is defined as seven years after Fluke discontinues manufacturing the product, but the warranty period shall be at least ten years from
the date of purchase. This warranty does not cover fuses, disposable batteries, damage from neglect, misuse, contamination, alteration,
accident or abnormal conditions of operation or handling, including failures caused by use outside of the product’s specifications, or normal
wear and tear of mechanical components. This warranty covers the original purchaser only and is not transferable.
For ten years from the date of purchase, this warranty also covers the LCD. Thereafter, for the lifetime of the DMM, Fluke will replace the LCD
for a fee based on then current component acquisition costs.
To establish original ownership and prove date of purchase, please complete and return the registration card accompanying the product, or
register your product on http://www.fluke.com
defective product purchased through a Fluke authorized sales outlet and at the applicable international price. Fluke reserves the right to
charge for importation costs of repair/replacement parts if the product purchased in one country is sent for repair elsewhere.
If the product is defective, contact your nearest Fluke authorized service center to obtain return authorization information, then send the
product to that service center, with a description of the difficulty, postage and insurance prepaid (FOB Destination). Fluke assumes no risk
for damage in transit. Fluke will pay return transportation for product repaired or replaced in-warranty. Before making any non-warranty
repair, Fluke will estimate cost and obtain authorization, then invoice you for repair and return transportation.

THIS WARRANTY IS YOUR ONLY REMEDY. NO OTHER WARRANTIES, SUCH AS FITNESS FOR A PARTICULAR PURPOSE, ARE
EXPRESSED OR IMPLIED. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL
DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY. AUTHORIZED RESELLERS ARE
NOT AUTHORIZED TO EXTEND ANY DIFFERENT WARRANTY ON FLUKE’S BEHALF. Since some states do not allow the exclusion or
limitation of an implied warranty or of incidental or consequential damages, this limitation of liability may not apply to you. If any provision of
this warranty is held invalid or unenforceable by a court or other decision-maker of competent jurisdiction, such holding will not affect the
validity or enforceability of any other provision.

. Fluke will, at its option, repair at no charge, replace or refund the purchase price of a

5/07

Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.

Fluke Europe B.V.
P.O. Box 1186
5602 BD Eindhoven
The Netherlands

Table of Contents

Title Page

Introduction .................................................................................................................... 1

How to Contact Fluke..................................................................................................... 1

Safety Information .......................................................................................................... 2

Features ......................................................................................................................... 6

Automatic Power-Off ................................................................................................. 13

Input Alert™ Feature ................................................................................................. 13

Power-Up Options ..................................................................................................... 13

How to Make Measurements.......................................................................................... 15

AC and DC Voltage Measurements........................................................................... 15

Zero Input Behavior of True-rms Meters (28 II) ......................................................... 16

Low-Pass Filter (28 II) ............................................................................................... 16

Temperature Measurements (28 II) ........................................................................... 17

Continuity Tests......................................................................................................... 18

Resistance Measurements ........................................................................................ 20

How to Use Conductance for High Resistance or Leakage Tests ............................. 22

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Users Manual

Capacitance Measurements ..................................................................................... 23

Diode Tests............................................................................................................... 24

AC or DC Current Measurements............................................................................. 26

Frequency Measurements ........................................................................................ 29

Duty Cycle Measurements........................................................................................ 31

How to Determine Pulse Width ................................................................................. 32

Bargraph........................................................................................................................ 32

Zoom Mode (Power Up Option Only)........................................................................ 33

Uses for the Zoom Mode .......................................................................................... 33

HiRes Mode (28 II)......................................................................................................... 33

MIN MAX Recording Mode ............................................................................................ 34

Smooth Feature (Power Up Option Only)...................................................................... 34

AutoHOLD Mode ........................................................................................................... 36

Relative Mode................................................................................................................ 36

Maintenance .................................................................................................................. 37

General Maintenance................................................................................................ 37

Fuse Test.................................................................................................................. 37

How to Replace the Batteries.................................................................................... 38

How to Replace the Fuses........................................................................................ 39

Service and Parts .......................................................................................................... 39

General Specifications................................................................................................... 44

Detailed Specifications .................................................................................................. 46

27 II AC Voltage........................................................................................................ 46

28 II AC Voltage........................................................................................................ 47

DC Voltage, Conductance, and Resistance.............................................................. 48

Temperature (28 II Only)........................................................................................... 49

AC Current................................................................................................................ 49

DC Current................................................................................................................ 50

Capacitance.............................................................................................................. 50

ii

Contents (continued)

Diode ......................................................................................................................... 51

Frequency ................................................................................................................. 51

Frequency Counter Sensitivity and Trigger Levels .................................................... 51

Duty Cycle (Vdc and mVdc) ...................................................................................... 52

Input Characteristics.................................................................................................. 52

MIN MAX Recording.................................................................................................. 53

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iv

List of Tables

Table Title Page

1. Symbols................................................................................................................................. 5

2. Inputs .................................................................................................................................... 6

3. Rotary Switch Positions......................................................................................................... 7

4. Pushbuttons .......................................................................................................................... 8

5. Display Features ................................................................................................................... 11

6. Power-Up Options ................................................................................................................. 14

7. Functions and Trigger Levels for Frequency Measurements................................................. 30

8. MIN MAX Functions .............................................................................................................. 35

9. Replacement Parts................................................................................................................ 41

10. Accessories ........................................................................................................................... 43

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vi

List of Figures

Figure Title Page

1. Display Features ................................................................................................................... 11

2. AC and DC Voltage Measurements ...................................................................................... 15

3. Low-Pass Filter...................................................................................................................... 17

4. Continuity Tests..................................................................................................................... 19

5. Resistance Measurements .................................................................................................... 21

6. Capacitance Measurements.................................................................................................. 23

7. Diode Tests ........................................................................................................................... 25

8. Current Measurements.......................................................................................................... 27

9. Components of Duty Cycle Measurements ........................................................................... 31

10. Current Fuse Test ................................................................................................................. 38

11. Battery and Fuse Replacement............................................................................................. 40

12. Replacement Parts................................................................................................................ 42

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viii

Introduction

XW Warning

Read “Safety Information” before using the
Meter.

Except where noted, the descriptions and instructions in
this manual refer to both Series II Models 27 and 28
multimeters (hereafter referred to as “the Meter”). Model
28 II appears in all illustrations.

The Model 27 II is an average-responding Digital
Multimeter while the 28 II is a True-rms Digital Multimeter.
In addition the 28 II measures temperature using a type-K
thermocouple.

How to Contact Fluke

To contact Fluke, call one of the following telephone
numbers:

Technical Support USA: 1-800-44-FLUKE (1-800­443-5853)

Calibration/Repair USA: 1-888-99-FLUKE (1-888­993-5853)

Canada: 1-800-36-FLUKE (1-800-363-5853)
Europe: [phone]
Japan: [phone]
Singapore: [phone]
Anywhere in the world: [phone]

Or, visit Fluke's website at www.fluke.com

To register your product, visit http://register.fluke.com.

To view, print, or download the latest manual supplement,
visit http://us.fluke.com/usen/support/manuals

.

.

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Users Manual

Safety Information

The Meter complies with:

• ISA-82.02.01

• CAN/CSA-C22.2 No. 61010-1-04

• IEC Standard No. 61010-1:2001

• Measurement Category III, 1000V, Pollution

Degree 2

• Measurement Category IV, 600V, Pollution

Degree 2
In this manual, a Warning identifies conditions and
actions that pose hazards to the user. A Caution
identifies conditions and actions that may damage the
Meter or the equipment under test.

Symbols used on the Meter and in this manual are
explained in Table 1.

XWWarning

To avoid possible electric shock or personal
injury, follow these guidelines:

• Use this Meter only as specified in this

manual or the protection provided by the
Meter might be impaired.

• 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.

• Make sure the battery door is closed and

secured before operating the Meter.

• Replace the battery as soon as the

battery indicator () appears.

• Remove test leads from the Meter before

opening the battery door.

2

Digital Multimeters

Safety Information

• 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 apply more than the rated

voltage, as marked on the Meter,
between the terminals or between any
terminal and earth ground.

• Never operate the Meter with the cover

removed or the case open.

• Use caution when working with voltages

above 30 V ac rms, 42 V ac peak, or 60 V
dc. These voltages pose a shock hazard.

• Use only the replacement fuses specified

by the manual.

• Use the proper terminals, function, and

range for measurements.

• Avoid working alone.

• 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 making electrical connections,

connect the common test lead before
connecting the live test lead; when
disconnecting, disconnect the live test
lead before disconnecting the common
test lead.

• Do not use the Meter if it operates

abnormally. Protection may be impaired.
When in doubt, have the Meter serviced.

• Do not use the Meter around explosive

gas, vapor or in damp or wet
environments.

• Use only three 1.5-V AA batteries,

properly installed in the Meter case, to
power the Meter.

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Users Manual

• When servicing the Meter, use only

specified replacement parts.

• When using probes, keep fingers behind

the finger guards on the probes.

• Do not use the Low-Pass Filter to verify

the presence of hazardous voltages.

Voltages greater than what is indicated

may be present. First, make a voltage

measurement without the filter to detect

the possible presence of hazardous

voltage. Then add the filter.

The following three warnings apply to MSHA
use.

• MSHA approved for use with three

Energizer P/N E91 or three Duracell P/N

MN1500 1.5 volt, “AA” alkaline batteries

only. All cells are to be replaced at the

same time with identical part number

cells in fresh air locations only.

• This multimeter is not to be used to

check electrical blasting circuits.

• This multimeter is not to be connected to

an electrically energized circuit in an
area where permissibility is required.

WCaution

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 all measurements.

• Before measuring current, check the

Meter’s fuses. (See “Fuse Test”.)

4

Digital Multimeters

Safety Information

Table 1. Symbols

B
F

X

W



R

CAT III

μ

®

~

AC (Alternating Current)

DC (Direct Current)

Hazardous voltage

Risk of Danger. Important information.
See Manual.

Battery. Low battery when displayed.

Continuity test or continuity beeper tone.

IEC Overvoltage Category III
CAT III equipment is designed to protect

against transients in equipment in fixed­equipment installations, such as
distribution panels, feeders and short
branch circuits, and lighting systems in
large buildings.

United States Department of Labor, Mine
Safety and Health Administration.

Inspected and licensed by TÜV Product
Services.

Do not dispose of this product as unsorted municipal waste. Go to Fluke’s website for recycling information.

J

I

P

)

T

E

CAT IV



;

Earth ground

Fuse

Conforms to European Union directives.

Conforms to relevant Canadian Standards
Association directives.

Double insulated

Capacitance

IEC Overvoltage Category IV
CAT IV equipment is designed to protect against

transients from the primary supply level, such as an
electricity meter or an overhead or underground utility
service.

Diode

Conforms to relevant Australian standards.

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Users Manual

Features

Tables 2 through 5 briefly describe the features of the Meter.

Table 2. Inputs

Terminal Description

A



COM



Input for 0 A to 10.00 A current (10 - 20 A overload for 30 seconds maximum), current frequency, and
duty cycle measurements.

Input for 0 μA to 400 mA current measurements (600 mA for 18 hrs) and current frequency and duty
cycle.

Return terminal for all measurements.

Input for voltage, continuity, resistance, diode, capacitance, frequency, temperature (28 II only), and
duty cycle measurements.

6

gaq112.eps

Digital Multimeters

Features

Table 3. Rotary Switch Positions

Switch Position

Any Position When the Meter is turned on, the Meter model number briefly appears on the display.

Function

K AC voltage measurement

 (yellow) for low-pass filter () (28 II only)

Press

L DC voltage measurement



 Press  for continuity test.

600 mV dc voltage range

Press  (yellow) for temperature () (28 II only)

e Resistance measurement
Press  (yellow) for capacitance measurement.

 Diode test





AC current measurements from 0 mA to 10.00 A

 (yellow) for dc current measurements, from 0 mA to 10.00 A.

Press
AC current measurements from 0 μA to 6000 μA

 (yellow) for dc current measurements from 0 μA to 6000 μA.

Press

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Table 4. Pushbuttons

Button



(Yellow)



Switch

Position



Any switch
position





Any switch
position

MIN MAX
recording

Frequency
counter

Selects capacitance









Switches between °C and °F. (28 II only)

Selects temperature (28 II only)

Selects ac low-pass filter function (28 II only)

Switches between dc and ac current

Switches between dc and ac current

Switches between the ranges available for the selected function. To return to autoranging, hold
the button down for 1 second.

AutoHOLD (formerly TouchHold) captures the present reading on the display. When a new,
stable reading is detected, the Meter beeps and displays the new reading.

Stops and starts recording without erasing recorded values.

Stops and starts the frequency counter.

Function

8

Digital Multimeters

Features

Table 4. Pushbuttons (cont.)

Button



Switch

Position

Continuity


MIN MAX
recording

Hz, Duty
Cycle

 Any switch

position



Any switch
position

Function

Turns the continuity beeper on and off

Switches between Peak (250 μs) and Normal (100 ms) response times. (28 II only)

Toggles the meter to trigger on positive or negative slope.

Turns the button backlight and display backlight on, makes them brighter, and turns them off.
For Model 28 II, hold

appears on the display. To return to the 3-1/2 digit mode, hold
HiRes=19,999

Starts recording of minimum and maximum values. Steps the display through MAX, MIN, AVG
(average), and present readings. Cancels MIN MAX (hold for 1 second)

 down for one second to enter the HiRes digit mode. The “HiRes” icon

 down for one second.

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Users Manual

Table 4. Pushbuttons (cont.)

Button Switch Position Function



(Relative
mode)



10

Any switch
position

Any switch
position except
diode test

Stores the present reading as a reference for subsequent readings. The display is
zeroed, and the stored reading is subtracted from all subsequent readings.

Press  for frequency measurements.
Starts the frequency counter.

Press again to enter duty cycle mode.

Digital Multimeters

Features

Number Feature Indication

Negative readings, In relative mode,
this sign indicates that the present
input is less than the stored
reference.

High voltage present at the input.
Appears if the input voltage is 30 V
or greater (ac or dc), Also appears in
low-pass filter mode. Also appears in
cal, Hz, and duty cycle modes.

AutoHOLD is active.

Display HOLD is active,

Peak Min Max modes and the
response time is 250 μs (28 II only).

Minimum-maximum recording mode.

Low-pass filter mode (28 II Only).
See “Low-pass Filter (28 II)”.

Figure 1. Display Features

Table 5. Display Features

Number Feature Indication

Polarity indicator for the analog
bargraph.

Positive or negative slope indicator
for Hz/duty cycle triggering.

The continuity beeper is on.

Relative (REL) mode is active.

Smoothing is active.









Trig±







gaq101.eps

 -

 








 





MAX MIN

AVG

 

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Users Manual

Table 5. Display Features (cont.)

Number Feature Indication

Low battery. XW Warning: To

avoid false readings, which

 

could lead to possible electric
shock or personal injury,
replace the battery as soon as
the battery indicator appears.



A, μA, mA amperes (amps), microamp, milliamp

V, mV volts, millivolts
μF, nF microfarad, nanofarad
nS nanosiemens

%

Percent. Used for duty cycle
measurements.

Ω, MΩ, kΩ ohm, megohm, kilohm
Hz, kHz hertz, kilohertz



AC DC Alternating current, direct current

Diode test mode.

Number Feature Indication

 °C, °F



610000 mV Displays selected range

 HiRes



Auto

Manual



Degrees Celsius, Degrees
Fahrenheit

High resolution (Hi Res) mode.
HiRes=19,999 (28 II only)

Autorange mode. Automatically
selects the range with the best
resolution

Manual range mode

The number of segments is relative
to the full-scale value of the selected
range. In normal operation 0 (zero) is
on the left. The polarity indicator at
the left of the graph indicates the
polarity of the input. The graph does
not operate with the capacitance, or
frequency counter functions. For
more information, see “Bargraph”.
The bargraph also has a zoom
function, as described under "Zoom
Mode".

12

Digital Multimeters

Features

Table 5. Display Features (cont.)

Number Feature Indication

--

Overload condition is detected.

0L

Error Messages

bAtt

di'c

CAL Err

EEPr

Err

0PEn

F2_

LEAd

Replace the battery immediately.

In the capacitance function, too much electrical
charge is present on the capacitor being tested.

Invalid calibration data. Calibrate Meter.

Invalid EEPROM data. Have the Meter serviced.

Open thermocouple detected.

Invalid model. Have the Meter serviced.

W Test lead alert. Displayed when the test leads are
in the

A or mA/μA terminal and the selected rotary

switch position does not correspond to the terminal
being used.

Automatic Power-Off

The Meter automatically turns off if you do not turn the
rotary switch or press a button for 30 minutes. If MIN
MAX Recording is enabled, the Meter will not power off.
Refer to Table 6 to disable automatic power-off.

Input Alert™ Feature

If a test lead is plugged into the mA/μA or A terminal, but
the rotary switch is not set to the correct current position,
the beeper warns you by making a chirping sound and
the display flashes “LEAd”, This warning is intended to
stop you from attempting to measure voltage, continuity,
resistance, capacitance, or diode values with the leads
are plugged into a current terminal.

W Caution

Placing the probes across (in parallel with) a
powered circuit when a lead is plugged into a
current terminal can damage the circuit you
are testing and blow the Meter’s fuse. This
can happen because the resistance through
the Meter’s current terminals is very low, so
the Meter acts like a short circuit.

Power-Up Options

Holding a button down while turning the Meter on
activates a power-up option. Table 6 describes power-up
options.

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Users Manual

Table 6. Power-Up Options

Button Power-Up Option



(Yellow)



Disables automatic power-off feature (Meter normally powers off in 30 minutes).
The Meter reads “PoFF” until  is released.

Enables the Meter’s calibration mode and prompts for a password.
The Meter reads “CAL” and enters calibration mode. See 27 II/28 II Calibration Information.

 Enables the Meter’s smoothing feature. The Meter reads “'---” until  is released.
 Turns on all LCD segments.
 Disables the beeper for all functions. The Meter reads “bEEP” until  is released.





(Relative mode)



14

Disables auto backlight off (backlight normally disables after 2 minutes). The Meter reads “LoFF” until  is
released.

Enables zoom mode for the bargraph. The Meter reads “2rEL” until  is released.

Enables the Meter’s high impedance mode when the mV dc function is used.
The Meter reads “Hi2” until  is released. (28 II only)

Digital Multimeters

How to Make Measurements

How to Make Measurements

The following sections describe how to make
measurements with the Meter.

AC and DC Voltage Measurements

Model 28 II features true-rms readings, which are
accurate for distorted sine waves and other waveforms
(with no dc offset) such as square waves, triangle waves,
and staircase waves.

The Meter’s voltage ranges are 600.0 mV, 6.000 V,

60.00 V, 600.0 V, and 1000 V. The select the 600.0 mV
dc range, turn the rotary switch to mV.

Refer to Figure 2 to measure ac or dc voltage.

AC Voltage

Switch Box

V

DC Voltage

mV

V

+

Figure 2. AC and DC Voltage Measurements

gaq102.eps

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Users Manual

When measuring voltage, the Meter acts approximately
like a 10-MΩ (10,000,000 Ω) impedance in parallel with
the circuit. This loading effect can cause measurement
errors in high-impedance circuits. In most cases, the error
is negligible (0.1 % or less) if the circuit impedance is
10 kΩ (10,000 Ω) or less.

For better accuracy when measuring the dc offset of an
ac voltage, measure the ac voltage first. Note the ac
voltage range, then manually select a dc voltage range
equal to or higher than the ac range. This procedure
improves the accuracy of the dc measurement by
ensuring that the input protection circuits are not
activated.

Zero Input Behavior of True-rms Meters (28 II)

True-rms meters accurately measure distorted
waveforms, but when the input leads are shorted together
in the ac functions, the Meter displays a residual reading
between 1 and 30 counts. When the test leads are open,
the display readings may fluctuate due to interference.
These offset readings are normal. They do not affect the
Meter’s ac measurement accuracy over the specified
measurement ranges.

Unspecified input levels are:

• AC voltage: below 3 % of 600 mV ac, or 18 mV ac

• AC current: below 3 % of 60 mA ac, or 1.8 mA ac

Low-Pass Filter (28 II)

The 28 II is equipped with an ac low-pass filter. When
measuring ac voltage or ac frequency, press  to
activate the low-pass filter mode (). The Meter
continues measuring in the chosen mode, but now the
signal diverts through a filter that blocks unwanted
voltages above 1 kHz, refer to Figure 3. The lower
frequency voltages pass with reduced accuracy to the
measurement below 1 kHz. The low-pass filter can
improve measurement performance on composite sine
waves that are typically generated by inverters and
variable frequency motor drives.

• AC current: below 3 % of 600 μA ac, or 18 μA ac

16

Digital Multimeters

How to Make Measurements

XW Warning

To avoid possible electric shock or personal
injury, do not use the low-pass filter to verify
the presence of hazardous voltages.
Voltages greater than what is indicated may
be present. First, make a voltage
measurement without the filter to detect the
possible presence of hazardous voltage.
Then, select the filter.

Note

When the low-pass filter is selected, the Meter
goes to manual ranging mode. Select ranges by
pressing . Autoranging is not available with
the low-pass filter.

1 kHz

100 Hz

Figure 3. Low-Pass Filter

Temperature Measurements (28 II)

The Meter measures the temperature of a type-K
thermocouple (included). Choose between degrees
Celsius (°C) or degrees Fahrenheit (°F) by pushing
.

aom11f.eps

W Caution

To avoid possible damage to the Meter or
other equipment, remember that while the
Meter is rated for -200.0 °C to +1090.0 °C and

-328.0 °F to 1994 °F, the included type-K
thermocouple is rated to 260 °C. For
temperatures out of that range, use a higher
rated thermocouple.

Display ranges are -200.0 °C to +1090 °C and -328.0 °F
to 1994 °F. Readings outside of these ranges show 0L on
the Meter display. When there is no thermocouple
connected, the display also reads 0PEn.

To measure temperature, do the following:

1. Connect a type-K thermocouple to the Meter’s COM
and  terminals.

2. Turn the rotary switch to .

3. Push  to enter temperature mode.

4. Push  to choose Celsius or Fahrenheit.

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Users Manual

Continuity Tests

WCaution

To avoid possible damage to the Meter or to
the equipment under test, disconnect circuit
power and discharge all high-voltage
capacitors before testing for continuity.

The continuity test features a beeper that sounds as long
as a circuit is complete. The beeper allows you to perform
quick continuity tests without having to watch the display.

To test for continuity, set up the Meter as shown in
Figure 4.

Press  to turn the continuity beeper on or off.

The continuity function detects intermittent opens and
shorts lasting as little as 1 ms. A brief short causes the
Meter to emit a short beep.

18

Digital Multimeters

How to Make Measurements

For in-circuit tests, turn circuit power off.

ON
(closed)

Activates
continuity
beeper

OFF
(open)

Figure 4. Continuity Tests

gaq103.eps

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Users Manual

Resistance Measurements

WCaution

To avoid possible damage to the Meter or to
the equipment under test, disconnect circuit
power and discharge all high-voltage
capacitors before measuring resistance.

The Meter measures resistance by sending a small
current through the circuit. Because this current flows
through all possible paths between the probes, the
resistance reading represents the total resistance of all
paths between the probes.

The Meter's resistance ranges are 600.0 Ω, 6.000 kΩ,

60.00 kΩ, 600.0 kΩ, 6.000 MΩ, and 50.00 MΩ.

Set up the Meter as shown in Figure 5 to measure
resistance.

The following are some tips for measuring resistance:

• The measured value of a resistor in a circuit is often

different from the resistor's rated value.

• The test leads can add 0.1 Ω to 0.2 Ω of error to

resistance measurements. To test the leads, touch
the probe tips together and read the resistance of the
leads. If necessary, you can use the relative (REL)
mode to automatically subtract this value.

• The resistance function can produce enough voltage

to forward-bias silicon diode or transistor junctions,
causing them to conduct. If this is suspected, press
 to apply a lower current in the next higher
range. If the value is higher, use the higher value.
Refer to the Input Characteristics table in the
specifications section for typical short-circuit currents.

20

Digital Multimeters

How to Make Measurements

In-Circuit Resistance Measurements

Circuit Power

OFF

Figure 5. Resistance Measurements

Isolating a Potentiometer

1

2

3

Disconnect

1

Isolating a Resistor

2

3

Disconnect

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Users Manual

How to Use Conductance for High Resistance or Leakage Tests

Conductance, the inverse of resistance, is the ability of a
circuit to pass current. High values of conductance
correspond to low values of resistance.

The Meter's 60-nS range measures conductance in
nanosiemens (1 nS = 0.000000001 siemens). Because
such small amounts of conductance correspond to
extremely high resistance, the nS range lets you
determine the resistance of components up to
100,000 MΩ, 1/1 nS = 1,000 MΩ.

To measure conductance, set up the Meter for measuring
resistance as shown in Figure 5, then press  until
the nS indicator appears on the display.

The following are some tips for measuring conductance:

• High-resistance readings are susceptible to

electrical noise. To smooth out most noisy readings,
enter the MIN MAX recording mode; then step to the
average (AVG) reading.

• There is normally a residual conductance reading

with the test leads open. To ensure accurate
readings, use the relative (REL) mode to subtract
the residual value.

22

Digital Multimeters

How to Make Measurements

Capacitance Measurements

WCaution

To avoid possible damage to the Meter or to
the equipment under test, disconnect circuit
power and discharge all high-voltage
capacitors before measuring capacitance.
Use the dc voltage function to confirm that
the capacitor is discharged.

The Meter's capacitance ranges are 10.00 nF, 100.0 nF,

1.000 μF, 10.00 μF, 100.0 μF, and 9999 μF.

To measure capacitance, set up the Meter as shown in
Figure 6.

To improve the accuracy of measurements less than
1000 nF, use the relative (REL) mode to subtract the
residual capacitance of the Meter and leads.

Note

If too much electrical charge is present on the
capacitor being tested, the display shows
“diSC“.

Select

Capacitance

+
+
+

+
+
+
+
+

+

gaq104.eps

Figure 6. Capacitance Measurements

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Users Manual

Diode Tests

WCaution

To avoid possible damage to the Meter or to
the equipment under test, disconnect circuit
power and discharge all high-voltage
capacitors before testing diodes.

Use the diode test to check diodes, transistors, silicon
controlled rectifiers (SCRs), and other semiconductor
devices. This function tests a semiconductor junction by
sending a current through the junction, then measuring
the junction's voltage drop. A good silicon junction drops
between 0.5 V and 0.8 V.

To test a diode out of a circuit, set up the Meter as shown
in Figure 7. For forward-bias readings on any
semiconductor component, place the red test lead on the
component's positive terminal and place the black lead on
the component's negative terminal.

In a circuit, a good diode should still produce a forward­bias reading of 0.5 V to 0.8 V; however, the reverse-bias
reading can vary depending on the resistance of other
pathways between the probe tips.

A short beep sounds if the diode is good (<0.85 V). A
continuous beep sounds if the reading is ≤0.100 V. This
reading would indicate a short circuit. The display shows
“OL” if the diode is open.

24

Digital Multimeters

How to Make Measurements

Typical
Reading

Single Beep

Bad Diode

Forward Bias

+

Open

Figure 7. Diode Tests

Bad Diode

Reverse Bias

+

Shorted

or

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Users Manual

AC or DC Current Measurements

XWWarning

To avoid possible electric shock or personal
injury, never attempt an in-circuit current
measurement where the open-circuit
potential to earth is greater than 1000 V. You
may damage the Meter or be injured if the
fuse blows during such a measurement.

WCaution

To avoid possible damage to the Meter or to
the equipment under test:

• Check the Meter's fuses before

measuring current.

• Use the proper terminals, function, and

range for all measurements.

• Never place the probes across (in

parallel with) any circuit or component
when the leads are plugged into the
current terminals.

To measure current, you must break the circuit under
test, then place the Meter in series with the circuit.

The Meter's current ranges are 600.0 μA, 6000 μA,

60.00 mA, 400.0 mA, 6.000 A, and 10.00 A.

To measure current, refer to Figure 8 and proceed as
follows:

1. Turn off power to the circuit. Discharge all high­voltage capacitors.

2. Insert the black lead into the COM terminal. For
currents between 0 mA and 400 mA, insert the red
lead into the mA/μA terminal. For currents above
400 mA, insert the red lead into the A terminal.

Note

To avoid blowing the Meter's 400-mA fuse, use

μ

the mA/
current is less than 400 mA continuously or less
than 600 mA for 18 hours or less.

A terminal only if you are sure the

26

Digital Multimeters

How to Make Measurements

1

Circuit Power:

OFF to connect meter.

Total Current to Circuit

ON for measurement.
OFF to disconnect meter.

4

mA

A

3

A

5

2

Current Through One Component

5

gaq107.eps

Figure 8. Current Measurements

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27 II/28 II

Users Manual

3. If you are using the A terminal, set the rotary switch

to mA/A. If you are using the mA/μA terminal, set the
rotary switch to
(6 mA), or  for currents above 6000 μA.

4. To measure dc current, press .

5. Break the circuit path to be tested. Touch the black
probe to the more negative side of the break; touch
the red probe to the more positive side of the break.
Reversing the leads will produce a negative reading,
but will not damage the Meter.

6. Turn on power to the circuit; then read the display.
Be sure to note the unit given at the right side of the
display (μA, mA, or A).

7. Turn off power to the circuit and discharge all high­voltage capacitors. Remove the Meter and restore
the circuit to normal operation.

 for currents below 6000 μA

The following are some tips for measuring current:

• If the current reading is 0 and you are sure the Meter

is set up correctly, test the Meter's fuses as
described under "Testing the Fuses".

• A current meter drops a small voltage across itself,

which might affect circuit operation. You can
calculate this burden voltage using the values listed
in the specifications in the Input Characteristics table.

28

Digital Multimeters

How to Make Measurements

Frequency Measurements

The Meter measures the frequency of a voltage or current
signal by counting the number of times the signal crosses
a threshold level each second.

Table 7 summarizes the trigger levels and applications for
measuring frequency using the various ranges of the
Meter's voltage and current functions.

To measure frequency, connect the Meter to the signal
source; then press
trigger slope between + and -, as indicated by the symbol
at the left side of the display (refer to Figure 9 under
"Duty Cycle"). Pressing  stops and starts the
counter.

The Meter autoranges to one of five frequency ranges:

199.99 Hz, 1999.9 Hz, 19.999 kHz, 199.99 kHz, and
greater than 200 kHz. For frequencies below 10 Hz, the
display is updated at the frequency of the input. Below

0.5 Hz, the display may be unstable.

. Pressing  switches the

The following are some tips for measuring frequency:

• If a reading shows as 0 Hz or is unstable, the input

signal may be below or near the trigger level. You
can usually correct these problems by selecting a
lower range, which increases the sensitivity of the
Meter. In the L function, the lower ranges also have
lower trigger levels.

If a reading seems to be a multiple of what you expect,
the input signal may be distorted. Distortion can cause
multiple triggerings of the frequency counter. Selecting a
higher voltage range might solve this problem by
decreasing the sensitivity of the Meter. You can also try
selecting a dc range, which raises the trigger level. In
general, the lowest frequency displayed is the correct
one.

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Users Manual

Table 7. Functions and Trigger Levels for Frequency Measurements

Function Range

K

K

L

m

L
L
L
L

R e E G

\

μAF

^

AF 6 A, 10 A .30 A, 3.0 A

6 V, 60 V,
600 V, 1000 V

600 mV ±30 mV High-frequency 5 V logic signals. (The dc-coupling of the L function can

600 mV 40 mV Refer to the measurement tips given before this table.

6 V 1.7 V 5 V logic signals (TTL).

60 V 4 V Automotive switching signals.

600 V 40 V Refer to the measurement tips given before this table.

1000 V 100 V

All ranges ±5 % of scale AC current signals.

600 μA, 6000 μA 30 μA , 300 μA Refer to the measurement tips given before this table.

60 mA, 400 mA 3.0 mA , 30 mA

Approximate

Trigger Level

±5 % of scale Most signals.

Frequency counter characteristics are not available or specified for these functions.

Typical Application

attenuate high-frequency logic signals, reducing their amplitude enough to
interfere with triggering.)

30

Digital Multimeters

How to Make Measurements

Duty Cycle Measurements

Duty cycle (or duty factor) is the percentage of time a
signal is above or below a trigger level during one cycle
(Figure 9). The duty cycle mode is optimized for
measuring the on or off time of logic and switching
signals. Systems such as electronic fuel injection systems
and switching power supplies are controlled by pulses of
varying width, which can be checked by measuring duty
cycle.

To measure duty cycle, set up the Meter to measure
frequency; then press Hz a second time. As with the
frequency function, you can change the slope for the
Meter's counter by pressing .

+Slope

Trigger Point

30% Above

+Slope

Figure 9. Components of Duty Cycle Measurements

-Slope
Trigger Point

100%

For 5-V logic signals, use the 6-V dc range. For 12-V
switching signals in automobiles, use the 60 V dc range.
For sine waves, use the lowest range that does not result
in multiple triggering. (Normally, a distortion-free signal
can be up to ten times the amplitude of the selected
voltage range.)

If a duty cycle reading is unstable, press MIN MAX; then
scroll to the AVG (average) display.

70% Below

-Slope

iyf.eps

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Users Manual

How to Determine Pulse Width

For a periodic waveform (its pattern repeats at equal time
intervals), you can determine the amount of time that the
signal is high or low as follows:

1. Measure the signal's frequency.

2. Push  a second time to measure the signal's
duty cycle. Push  to select a measurement of
the signal's positive or negative pulse, refer to
Figure 9.

3. Use the following formula to determine the pulse
width:

Pulse Width =

(in seconds) Frequency

% Duty Cycle ÷ 100

Bargraph

The analog bargraph functions like the needle on an
analog meter, but without the overshoot. The bargraph
updates 40 times per second. Because the graph
responds 10 times faster than the digital display, it is
useful for making peak and null adjustments and
observing rapidly changing inputs. The graph is not
shown for capacitance, frequency counter functions,
temperature, or peak min max.

The number of lit segments indicates the measured value
and is relative to the full-scale value of the selected
range.

In the 60-V range, for example, the major divisions on the
scale represent 0, 15, 30, 45, and 60 V. An input of -30 V
lights the negative sign and the segments up to the
middle of the scale.

The bargraph also has a zoom function, as described
under "Zoom Mode".

32

Digital Multimeters

HiRes Mode (28 II)

Zoom Mode (Power Up Option Only)

To use the Rel Zoom Bargraph:

1. Hold down
display reads “2rEL”.

2. Select the relative mode by pressing

3. The center of the bargraph now represents zero and
the sensitivity of the bargraph increases by a factor
of 10. Measured values more negative than the
stored reference activate segments to the left of
center; values more positive activate segments to the
right of center.

 while turning the Meter on. The

 again.

Uses for the Zoom Mode

The relative mode, combined with the increased
sensitivity of the bargraph's zoom mode, helps you make
fast and accurate zero and peak adjustments.

For zero adjustments, set the Meter to the desired
function, short the test leads together, press
connect the leads to the circuit under test. Adjust the
circuit's variable component until the display reads zero.
Only the center segment on the zoom bargraph is lit.

For peak adjustments, set the Meter to the desired
function, connect the leads to the circuit under test; then
press

. The display reads zero. As you adjust for a

positive or negative peak, the bargraph length increases
to the right or left of zero. If an overange symbol (< >)

; then

lights, press  twice to set a new reference; then
continue with the adjustment.

HiRes Mode (28 II)

On a Model 28 II, push  for one second to enter the
high-resolution (HiRes) 4-1/2 digit mode. Readings are
displayed at 10 times the normal resolution with a
maximum display of 19,999 counts. The HiRes mode
works in all modes except capacitance, frequency counter
functions, temperature, and the 250 μs (peak) MIN MAX
modes.

To return to the 3-1/2 digit mode, push  for one second.

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27 II/28 II

Users Manual

MIN MAX Recording Mode

The MIN MAX mode records minimum and maximum
input values. When the inputs go below the recorded
minimum value or above the recorded maximum value,
the Meter beeps and records the new value. This mode
can be used to capture intermittent readings, record
maximum readings while you are away or record readings
while you are operating the equipment under test and
cannot watch the Meter. MIN MAX mode can also
calculate an average of all readings taken since the MIN
MAX mode was activated. To use MIN MAX mode, refer
to the functions in Table 8.

Response time is the length of time an input must stay at
a new value to be recorded. A shorter response time
captures shorter events, but with decreased accuracy.
Changing the response time erases all recorded
readings. Model 27 II has 100 millisecond response time;
Model 28 II has 100 millisecond and 250 μs (peak)
response times. The 250 μs response time is indicated by
“” on the display.

The 100 millisecond response time is best for recording
power supply surges, inrush currents, and finding
intermittent failures.

The true average value (AVG) displayed is the
mathematical integral of all readings taken since the start
of recording (overloads are discarded). The average
reading is useful for smoothing out unstable inputs,

calculating power consumption, or estimating the
percentage of time a circuit is active.

Min Max records the signal extremes lasting longer than
100 ms.

Peak records the signal extremes lasting longer than
250 μs.

Smooth Feature (Power Up Option Only)

When the input signal changes rapidly, “smoothing”
provides a steadier reading on the display.

To use the smooth feature:

1. Hold down  while turning the Meter on. The
display will read “'---” until  is released.

2. The smooth icon () will appear on the left side
of the display to let you know that smoothing is
active.

34

Digital Multimeters

Smooth Feature (Power Up Option Only)

Table 8. MIN MAX Functions

Button MIN MAX Function

Enter MIN MAX recording mode. The Meter is locked in the range displayed before you



entered MIN MAX mode. (Select the desired measurement function and range before
entering MIN MAX.) The Meter beeps each time a new minimum or maximum value is
recorded.



(while in MIN MAX mode)



PEAK MIN MAX

 Stop recording without erasing stored values. Press again to resume recording.



(hold for 1 second)

Step through maximum (MAX), minimum (MIN), average (AVG) and present values.

Model 28 II only: Select 100 ms or 250 μs response time. (The 250 μs response time is
indicated by  on the display.) Stored values are erased. The present and AVG
(average) values are not available when 250 μs is selected.

Exit MIN MAX mode. Stored values are erased. The Meter stays in the selected range.

35

27 II/28 II

Users Manual

AutoHOLD Mode

XWWarning

To avoid possible electric shock or personal
injury, do not use AutoHOLD mode to
determine that circuits are without power.
The AutoHOLD mode will not capture
unstable or noisy readings.

The AutoHOLD mode captures the present reading on
the display. When a new, stable reading is detected, the
Meter beeps and displays the new reading. To enter or
exit AutoHOLD mode, press

.

Relative Mode

Selecting relative mode () causes the Meter to zero
the display and store the present reading as the reference
for subsequent measurements. The Meter is locked into
the range selected when you pressed . Press

 again to exit this mode.

In relative mode, the reading shown is always the
difference between the present reading and the stored
reference value. For example, if the stored reference
value is 15.00 V and the present reading is 14.10 V, the
display shows -0.90 V.

36

Digital Multimeters

Maintenance

Maintenance

XWWarning

To avoid possible electric shock or personal
injury, repairs or servicing not covered in
this manual should be performed only by
qualified personnel as described in the

27 II/28 II Calibration Information.

General Maintenance

Periodically wipe the case with a damp cloth and mild
detergent. Do not use abrasives or solvents.

Dirt or moisture in the terminals can affect readings and
can falsely activate the Input Alert feature. Clean the
terminals as follows:

1. Turn the Meter off and remove all test leads.

2. Shake out any dirt that may be in the terminals.

3. Soak a clean swab with mild detergent and water.
Work the swab around in each terminal. Dry each
terminal using canned air to force the water and
detergent out of the terminals.

Fuse Test

As shown in Figure 10, with the Meter in the 
function, insert a test lead into the  jack and place the
probe tip on the other end of the test lead against the
metal of the current input jack. If “LEAd” appears in the
display, the probe tip has been inserted too far into the
amps input jack. Back the lead out a bit until the message
disappears and either OL or a resistance reading appears
in the display. The resistance value should be as shown
in Figure 10. If the tests give readings other than those
shown, have the Meter serviced.

XWWarning

To avoid electrical shock or personal injury,
remove the test leads and any input signals
before replacing the battery or fuses. To
prevent damage or injury, install ONLY
specified replacement fuses with the
amperage, voltage, and speed ratings shown
in Table 9.

37

27 II/28 II

Users Manual

Good 0.44 A fuse: 0.995 kΩ to

1.005 kΩ

Replace fuse: OL

Touch top half

of input contacts

Good 11 A fuse: 00.0 Ω to

00.5 Ω

Replace fuse: OL

Figure 10. Current Fuse Test

gaq105.eps

How to Replace the Batteries

Replace the batteries with three AA batteries
(NEDA 15A IEC LR6).

XWWarning

To avoid false readings, which could lead to
possible electric shock or personal injury,
replace the battery as soon as the battery
indicator () appears. If the display shows
“batt” the Meter will not function until the
battery is replaced.

MSHA approved for use with three Energizer
P/N E91 or three Duracell P/N MN1500 1.5
volt, “AA” alkaline batteries only. All cells are
to be replaced at the same time with identical
part number cells in fresh air locations only.

Replace the battery as follows, refer to Figure 11:

1. Turn the rotary switch to OFF and remove the test
leads from the terminals.

2. Remove the six Phillips-head screws from the case
bottom and remove the battery door ().

Note

While lifting the battery door, ensure the rubber
gasket stays attached to the battery
compartment barrier.

3. Remove the three batteries and replace all three with
AA Alkaline batteries ().

38

Digital Multimeters

Service and Parts

4. Ensure the battery compartment gasket () is
properly installed around the outside edge of the
battery compartment barrier.

5. Replace the battery door by aligning the battery
compartment barrier with battery compartment.

6. Secure the door with the six Phillips-head screws.

How to Replace the Fuses

Referring to Figure 11, examine or replace the Meter's
fuses as follows:

1. Turn the rotary switch to OFF and remove the test
leads from the terminals

2. Refer to step 2 under the How to Replace the
Batteries section above to remove the battery door.

3. Remove the fuse compartment seal () from the
fuse compartment.

4. Gently lift out the fuse compartment door () from
the fuse compartment.

5. Remove the fuse by gently prying one end loose,
then sliding the fuse out of its bracket ().

6. Install ONLY specified replacement fuses with the
amperage, voltage, and speed ratings shown in
Table 9. The 440-mA fuse is shorter than the 10-A
fuse. For correct placement of each fuse, note the
marking on the printed circuit board under each fuse.

7. Replace the fuse compartment door by aligning the
arrow on the fuse door with the arrow on the case
bottom and lowering the door into the fuse
compartment.

8. Replace the fuse compartment seal by aligning the
tab on the seal with the outline on the case bottom.
Ensure the seal () is properly seated.

9. Refer to steps four through six under the Replacing
the Batteries section above to reinstall the battery
door.

Service and Parts

If the Meter fails, check the battery and fuses. Review this
manual to verify proper use of the Meter.

Replacement parts and accessories are shown in Table 9
and Figure 12.

To order parts and accessories, refer to “How to Contact
Fluke”.

39

27 II/28 II

Users Manual

1

3

4

2

6

5

40

Figure 11. Battery and Fuse Replacement

gaq10.eps

Digital Multimeters

Service and Parts

Table 9. Replacement Parts

Description Qty.

Battery, AA 1.5 V 3 376756

Fuse, 0.440 A, 1000 V, FAST 1 943121

Fuse, 11 A, 1000 V, FAST 1 803293

Fuse Access Door 1 3400480

Screw 6 3861068

Gasket, Battery Door 1 3439087

Fuse Cap 1 3440546

Holster 1 3321048

Battery Door 1 3321030

Fluke Part or Model

Number

Alligator Clip, Black 1

AC72

Alligator Clip, Red 1

Test Lead Set 1 TL75

Integrated DMM Temperature Probe (28 II Only) 1 80BK-A

27 II / 28 II Users Manual CD 1 3368139

27 II / 28 II Getting Started Manual 1 3368142

W To ensure safety, use exact replacement only.

41

27 II/28 II

Users Manual

Battery

Door

Access Door

Fuse

11 A,

1000 V, Fast

1000 V, Fast

Fuse

Fuse

0.440 A,

Fuse Cap

Screw

Battery Door
Gasket

Battery
AA 1.5 V

Users Manual CD

Getting Started Manual

Figure 12. Replacement Parts

27 II/28 II

27 II/28 II

Alligator Clips

Holster

TL75

Test Lead Set

AC72

80BK-A Integrated DMM
Temperature Probe
(28 II only)

gaq111.eps

42

Digital Multimeters

Service and Parts

Table 10. Accessories

Item Description

AC72 Alligator Clips for use with TL75 test lead set

AC220 Safety Grip, Wide-Jaw Alligator Clips

TPAK ToolPak Magnetic Hanger

C25 Carrying Case, Soft

TL75 Silicone test lead set with probes

TL220 Industrial Test Lead Set

TL224 Test Lead Set, Heat-Resistant Silicone Modular

TP1 Test Probes, Flat Blade, Slim Reach

TP4 Test Probes, 4 mm diameter, Slim Reach

Fluke accessories are available from an authorized Fluke distributor.

43

27 II/28 II

Users Manual

General Specifications

Maximum voltage between any

terminal and earth ground............................................ 1000 V rms

W Fuse for mA inputs ..................................................440 mA, 1000 V FAST Fuse

W Fuse for A inputs .....................................................11 A, 1000 V FAST Fuse

Display

Digital .......................................................................... 6000 counts, updates 4/sec (Model 28 II also has 19,999 counts in high-resolution

Bargraph .....................................................................33 segments; updates 40/sec

Altitude

Operating ....................................................................2,000 meters

Storage .......................................................................10,000 meters

Temperature

Operating ....................................................................-15 °C to +55 °C, to -40 °C for 20 minutes when taken from 20 °C

Storage .......................................................................-55 °C to +85 °C (without battery)

-55 °C to +60 °C (with battery)

Temperature coefficient

28 II ............................................................................. 0.05 X (specified accuracy) / °C (<18 °C or >28 °C)

27 II ............................................................................. 0.1 X (specified accuracy) / °C (<18 °C or >28 °C)

mode).

44

Digital Multimeters

General Specifications

Electromagnetic Compatibility (EN 61326-1:1997).....In an RF field of 3 V/M, accuracy = specified accuracy +20 counts, except 600 μA dc

Relative Humidity ..........................................................0 % to 95 % (0 °C to 35 °C)

0 % to 70 % (35 °C to 55 °C)

Battery Type...................................................................3 AA Alkaline batteries, NEDA 15A IEC LR6, MSHA approved for use with three

Battery Life.....................................................................800 hrs typical without backlight (Alkaline)

Vibration.........................................................................Per MIL-PRF-28800 for a Class 2 instrument

Shock..............................................................................1 Meter drop per IEC 61010 (3 Meter drop with holster)

Size (H x W x L)..............................................................1.80 in x 3.95 in x 8.40 in (4.57 cm x 10.0 cm x 21.33 cm)

Size with Holster............................................................ 2.50 in x 3.95 in x 7.80 in (6.35 cm x 10.0 cm x 19.81 cm)

Weight ............................................................................1.14 lb (517.1 g)

Weight with Holster and Flex-Stand ............................1.54 lb (698.5 g)

Safety Compliance ........................................................Complies with ANSI/ISA S82.01-2004, CAN/CSA C22.2 61010-1-04 to 600 V

Certifications .................................................................CSA, TÜV, P,

IP Rating.........................................................................67 (Protected against dust and the effect of immersion between 15 cm and 1 m for

MSHA Approval No ....................................................... 18-A100015-0

range total accuracy = specified accuracy +60 counts. Temperature not specified

Energizer P/N E91 or three Duracell P/N MN1500 1.5 Volt, AA alkaline batteries
only.

Measurement Category IV. Licensed by TÜV to EN61010-1

;, GOST, s

30 min)

45

27 II/28 II

Users Manual

Detailed Specifications

For all detailed specifications:
Accuracy is specified for 2 years after calibration, at operating temperatures of 18 °C to 28 °C, with relative humidity at 0 % to 95 %.

Accuracy specifications take the form of ±([% of Reading] + [Number of least-significant digits]). For Model 28 II in the 4 ½-digit mode,
multiply the number of least-significant digits (counts) by 10.

27 II AC Voltage

Range Resolution

600.0 mV 0.1 mV

6.000 V 0.001 V

60.00 V 0.01 V

600.0 V 0.1 V
1000 V 1 V ±(1.0 % + 3) ±(3 % + 3) Unspecified

[1] Specified to a maximum of 300 V ac
[2] Below 5 % of range, temperature coefficient is 0.15 X (specified accuracy)/ °C (>40 °C).

40 Hz – 2 kHz 2 kHz – 10 kHz 10 kHz – 30 kHz

±(0.5 % + 3) ±(2 % + 3)

Accuracy

[2]

±(4 % + 10)

[1]

±(4 % + 10)

46

Digital Multimeters

Detailed Specifications

28 II AC Voltage

AC conversions are ac-coupled and valid from 3 % to 100 % of range.

Range Resolution

600.0 mV 0.1 mV

45 – 65 Hz 15 – 200 Hz 200 – 440 Hz 440 Hz – 1 kHz 1 – 5 kHz 5 – 20 kHz

±(0.7 % + 4) ±(2 % + 4)

Accuracy

±(2 % + 20)

[2]

6.000 V 0.001 V

60.00 V 0.01 V Unspecified

±(1.0 % + 4)

600.0 V 0.1 V

1000 V 1 V

Low-Pass Filter

[1] Below 30 Hz, use smoothing function.

[2] Below 10 % of range, add 12 counts.

[3] Frequency range: 1 to 2.5 kHz

[4] Specification increases from -1 % to -6 % at 440 Hz when filter is used.

±(0.7 % + 2)

±(1.0 % + 4)

[1]

+1.0 % + 4

-6.0 % - 4

[1]

±(2 % + 4)

[3]

Unspecified

Unspecified Unspecified

Unspecified Unspecified Unspecified

[4]

47

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DC Voltage, Conductance, and Resistance

Function Range Resolution Accuracy

mV dc 600.0 mV 0.1 mV ±(0.1 % + 1)

6.000 V 0.001 V

V dc

Ω

nS

[1] Add 0.5 % of reading when measuring above 30 MΩ in the 50 MΩ range, and 20 counts below 33 nS in the 60 nS range.

[2] When using the rel function to compensate for offsets.

60.00 V 0.01 V

600.0 V 0.1 V

1000 V 1 V

600.0 Ω 0.1 Ω

6.000 kΩ 0.001 kΩ

60.00 kΩ 0.01 kΩ

600.0 kΩ 0.1 kΩ

6.000 MΩ 0.001 MΩ

50.00 MΩ 0.01 MΩ

60.00 nS 0.01 nS

±(0.05 % + 1)

±(0.2 % + 2)

±(0.2 % + 1)

±(1.0 % + 1)

±(1.0 % + 10)

[2]

[1]

[1,2]

48

Digital Multimeters

Detailed Specifications

Temperature (28 II Only)

Range Resolution

-200 °C to +1090 °C

-328 °F to +1994 °F

[1] Does not include error of the thermocouple probe.
[2] Accuracy specification assumes ambient temperature stable to ± 1 °C. For ambient temperature changes of ± 5 °C, rated accuracy

applies after 2 hour.

0.1 °C

0.1 °F

Accuracy

±(1.0 % + 10)
±(1.0 % + 18)

[1,2]

AC Current

Accuracy

Function Range Resolution Burden Voltage

μA ac

mA ac

A ac

[1] AC conversion for the 27 II is ac coupled and calibrated to the rms value of a sine wave input.
[2] Below 300 counts, add 1 count and the temperature coefficient is 0.15 x (specified accuracy) / °C (>40 °C).
[3] AC conversions for the 28 II are ac coupled, true rms responding, and valid from 3 % to 100 % of range, except 400 mA range.

[4] 400 mA continuous. 600 mA for 18 hr maximum.
[5] W 10 A continuous up to 35 °C. <20 minutes on, 5 minutes off at 35 °C to 55 °C. >10 A to 20 A for 30 seconds maximum,

[6] >10 A accuracy unspecified.

600.0 μA 0.1 μA 100 μV/μA
6000 μA 1 μA 100 μV/μA

60.00 mA 0.01 mA 1.8 mV/mA

400.0 mA

[4]

0.1 mA 1.8 mV/mA

6.000 A 0.001 A 0.03 V/A

[5,6]

10.00 A

(5 % to 100 % of range) and 10 A range (15 % to 100 % or range).

5 minutes off.

0.01 A 0.03 V/A

[1,2]

27 II

(40 Hz – 1 kHz)

(45 Hz – 2 kHz)

±(1.5 % + 2) ±(1.0 % + 2)

28 II

[3]

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Users Manual

DC Current

Function Range Resolution Burden Voltage

μA dc

600.0 μA 0.1 μA 100 μV/μA ±(0.2 % + 4) ±(0.2 % + 4)

27 II 28 II

6000 μA 1 μA 100 μV/μA ±(0.2 % + 2) ±(0.2 % + 2)

mA dc

A dc

[1] 400 mA continuous; 600 mA for 18 hr maximum.
[2] W 10 A continuous up to 35 °C. <20 minutes on, 5 minutes off at 35 °C to 55 °C. >10 A to 20 A for 30 seconds maximum, 5

[3] >10 A accuracy unspecified.

60.00 mA 0.01 mA 1.8 mV/mA ±(0.2 % + 4) ±(0.2 % + 4)

[1]

400.0 mA

0.1 mA 1.8 mV/mA ±(0.2 % + 2) ±(0.2 % + 2)

6.000 A 0.001 A 0.03 V/A ±(0.2 % + 4) ±(0.2 % + 4)

[2,3]

10.00 A

minutes off.

0.01 A 0.03 V/A ±(0.2 % + 2) ±(0.2 % + 2)

Accuracy

Capacitance

Range Resolution Accuracy

10.00 nF 0.01 nF

100.0 nF 0.1 nF

1.000 μF 0.001 μF

10.00 μF 0.01 μF

100.0 μF 0.1 μF
9999 μF 1 μF

[1] With a film capacitor or better, using the rel mode to zero residual.

±(1.0 % + 2)

±(1.0 % + 2)

[1]

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Digital Multimeters

Detailed Specifications

Diode

Range Resolution Accuracy

2.000 V 0.001 V ±(1.0 % + 1)

Frequency

Range Resolution Accuracy

199.99 Hz 0.01 Hz

1999.9 Hz 0.1 Hz

19.999 kHz 0.001 kHz

199.99 kHz 0.01 kHz

>200 kHz 0.1 kHz Unspecified

[1] From 0.5 Hz to 200 kHz and for pulse widths >2 μs.

±(0.005 % + 1)

[1]

Frequency Counter Sensitivity and Trigger Levels

Input Range

600 mV dc 70 mV (to 400 Hz) 70 mV (to 400 Hz) 40 mV

600 mV ac 150 mV 150 mV -

6 V 0.3 V 0.7 V 1.7 V
60 V 3 V 7 V (≤140 kHz) 4 V
600 V 30 V 70 V (≤14.0 kHz) 40 V
1000 V 100 V 200 V (≤1.4 kHz) 100 V

Minimum Sensitivity (RMS Sine Wave)

5 Hz – 20 kHz 0.5 Hz – 200 kHz

Approximate Trigger Level

(DC Voltage Function)

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Duty Cycle (Vdc and mVdc)

Range Accuracy

0.0 % to 99.9 %

[1] 0.5 Hz to 200 kHz, pulse width >2 μs. Pulse width range is determined by the frequency by the frequency of the signal.

[1]

Within ± (0.2 % per kHz + 0.1 %) for rise times < 1 μs.

Input Characteristics

Function

L



K

Overload

Protection

1000 V rms

1000 V rms

1000 V rms

Input

Impedance

(nominal)

10 MΩ <100 pF

10 MΩ < 100 pF

(ac-coupled)

Common Mode

Rejection Ratio

(1 kΩ unbalance)

> 120 dB at dc, 50 Hz

or 60 Hz

> 120 dB at dc, 50 Hz

or 60 Hz

> 60 dB, dc to 60 Hz

Normal Mode Rejection

> 60 dB at 50 Hz or 60 Hz

> 60 dB at 50 Hz or 60 Hz

Ω
G

52

1000 V rms <2.8 V dc <850 mV dc <1.3 V dc 500 μA 100 μA 10 μA 1 μA 0.2 μA 0.1 μA

1000 V rms <2.8 V dc 2.200 V dc 1.0 mA typical

Open Circuit

Test Voltage

Full Scale Voltage Typical Short Circuit Current

To 6 MΩ

5 MΩ or

60 nS

600 Ω 6 kΩ 60 kΩ 600 kΩ 6 MΩ 50 MΩ

Digital Multimeters

Detailed Specifications

MIN MAX Recording

Accuracy Nominal Response

27 II 28 II

Specified accuracy ±12 counts for changes

100 ms to 80 %

100 ms to 80 %
(dc functions)

120 ms to 80 %
(ac functions)

250 μs (peak)

[1] For repetitive peaks: 1 ms for single events.

[1]

>200 ms in duration
(±40 counts in ac with beeper on)

Specified accuracy ±12 counts for
changes >200 ms in duration

Specified accuracy ±40 counts for
changes >350 ms and inputs >25 %
of range

Specified accuracy ±100 counts for
changes >250 μs in duration
(add ±100 counts for readings over
6000 counts)
(add ±100 counts for readings in Low
Pass mode)

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