Craftsman 81079 User Manual

Owner's Manual

True RMS Multimeter
with IR Thermometer

Model No.
81079

CAUTION: Read, understand and

follow Safety Rules and Operating
Instructions in this manual before
using this product.

© Sears, Roebuck and Co., Hoffman Estates, IL 60179 U.S.A.

www.craftsman.com 062006

• Safety

• Operation

• Maintenance

• Español

TABLE OF CONTENTS

Warranty Page 3
Safety Instructions 4
Safety Symbols 5
Control and Jacks 6
Symbols and Annunciators 6
Specifications 7
Battery Installation 10
Operating Instructions 11

DC Voltage Measurements 11
AC Voltage Measurements 12
DC Current Measurements 13
AC Current Measurements 14
Resistance Measurements 15
Continuity Check 16
Diode Test 16
Contact Temperature Measurements 17
Non-Contact Temperature Measurements 18
Capacitance Measurements 19
Frequency Measurements 20
% Duty Cycle Measurements 20
Autorange/Manual Range Selection 21
Relative Mode 21
Display Backlight 21
Data Hold 22
Auto Power Off 22
Low Battery indication 22
Wrong Connection Indication 22

Maintenance 23

Battery Replacement 24

Fuse Replacement 25
Troubleshooting 26
Service and Parts 26

2

ONE YEAR FULL WARRANTY

ONE YEAR FULL WARRANTY ON CRAFTSMAN PROFESSIONAL
TRUE RMS MULTIMETER
If this CRAFTSMAN Professional True RMS Multimeter fails to give
complete satisfaction within one year from the date of purchase,
RETURN IT TO THE NEAREST SEARS STORE OR OTHER
CRAFTSMAN OUTLET IN THE UNITED STATES, and Sears will replace
it, free of charge.
This warranty gives you specific legal rights, and you may also have
other rights which vary from state to state.
Sears, Roebuck and Co., Dept. 817WA, Hoffman Estates, IL 60179

For Customer Assistance Call 9am - 5pm (ET)
Monday through Friday 1-888-326-1006

WARNING: USE EXTREME CAUTION IN THE USE OF THIS
DEVICE. Improper use of this device can result in injury or

death. Follow all safeguards suggested in this manual in addition
to the normal safety precautions used in working with electrical
circuits. DO NOT service this device if you are not qualified to do
so.

3

SAFETY INSTRUCTIONS

This meter has been designed for safe use, but must be operated
with caution. The rules listed below must be carefully followed for
safe operation.

1. NEVER apply voltage or current to the meter that exceeds the

specified maximum:

V DC or V AC 600V DC/AC, 200Vrms on 400mV

Function Maximum Input

mA AC/DC 500mA 250V fast acting fuse
A AC/DC 20A 250V fast acting fuse(30

Frequency, Resistance,
Capacitance, Duty Cycle,
Diode Test, Continuity
Temperature 60V DC/24V AC

2. USE EXTREME CAUTION when working with high voltages

3. DO NOT measure voltage if the voltage on the "COM" input

jack exceeds 600V above earth ground

4. DO NOT measure current of circuits whose voltage is greater

than 500V above earth ground

5. NEVER connect the meter leads across a voltage source

while the function switch is in the resistance or diode mode.
Doing so can damage the meter

6. ALWAYS turn off the power and disconnect the test leads

before opening the cover to replace the fuse or battery

7. NEVER operate the meter unless the back cover is in place

and fastened securely

Input Limits

range

seconds max every 15 minutes)
250Vrms for 15sec max

4

SAFETY SYMBOLS

This symbol adjacent to another symbol,
terminal or operating device indicates that the
operator must refer to an explanation in the
Operating Instructions to avoid personal injury
or damage to the meter.

WARNING

CAUTION

MAX
600V

This WARNING symbol indicates a potentially
hazardous situation, which if not avoided,
could result in death or serious injury.

This CAUTION symbol indicates a potentially
hazardous situation, which if not avoided, may
result damage to the product.

This symbol advises the user that the
terminal(s) so marked must not be connected
to a circuit point at which the voltage with
respect to earth ground exceeds (in this case)
600 VAC or VDC.

This symbol adjacent to one or more terminals
identifies them as being associated with
ranges that may, in normal use, be subjected
to particularly hazardous voltages. For
maximum safety, the meter and its test leads
should not be handled when these terminals
are energized.

This symbol indicates that a device is
protected throughout by double insulation or
reinforced insulation.

This symbol indicates there is a potential
hazard from a laser light source.

5

CONTROLS AND JACKS

1. IR Thermometer and laser pointer

2. 4000 count LCD display

3. HOLD and Backlite button

4. SELECT button

5. Function switch

6. mA, uA and A input jacks

7. COM input jack

8. Positive input jack

9. RANGE hold button

10. RELATIVE button

11. Laser pointer button

Note: Tilt stand and battery compartment are on rear of unit.

SYMBOLS AND ANNUNCIATORS

•))) Continuity

Diode test

Laser pointer

Battery status

Test lead connection

error
n nano (10
(capacitance)
! micro (10
m milli (10
k kilo (10
M mega (10
Hz Hertz (frequency) V Volts
% Percent (duty ratio) REL Relative
AC Alternating current AUTO Autoranging
DC Direct current HOLD Data hold
ºF Degrees Fahrenheit ºC Degrees Centigrade

-9

)

-6

) (amps, cap)

-3

) (volts, amps) A Amps

3

) (ohms) F Farads (capacitance)

6

) (ohms) ! Ohms

6

SPECIFICATIONS

Function Range Resolution
DC

Voltage

AC
Voltage

DC
Current

AC
Current

NOTE: Accuracy is stated at 65oF to 83oF (18oC to 28oC) and less

400mV 0.1mV ±(0.3% reading + 2 digits)

4V 0.001V

40V 0.01V
400V 0.1V

600V 1V ±(0.8% reading + 3 digits)

50 to 400Hz 400Hz to 1kHz

400mV 0.1mV ±(1.5% reading

4V 0.001V
40V 0.01V

400V 0.1V

600V 1V ±(1.8% reading

400µA 0.1µA

4000µA 1µA

40mA 0.01mA

400mA 0.1mA

4A 0.001A
20A 0.01A

50 to 400Hz 400Hz to 1KHz

400µA 0.1µA

4000µA 1µA

40mA 0.01mA

400mA 0.1mA

4A 0.001A
20A 0.01A

than 75% RH.

±(0.5% reading + 2 digits)

+ 15 digits)

±(1.5% reading

+ 6 digits)

+ 6 digits)

±(1.5% reading + 3 digits)

±(2.5% reading + 5 digits)

±(1.8% reading

+ 8 digits)

±(3.0% reading
+ 8 digits)

Accuracy

±(2.5% reading

+ 15digits)

±(2.5% reading

+ 8 digits)

±(3% reading +

8 digits)

±(3.0% reading
+ 7 digits)

±(3.5% reading
+ 10 digits)

7

Function Range Resolution Accuracy

Resistance

apacitance

Frequency

(type-K)

(IR)

NOTE: Accuracy specifications consist of two elements:

• (% reading) – This is the accuracy of the measurement circuit.

• (+ digits) – This is the accuracy of the analog to digital

400! 0.1! ±(0.8% reading + 4 digits)

4k! 0.001k! ±(0.8% reading + 2 digits)

40k! 0.01k!

400k! 0.1k!

4M! 0.001M!

40M! 0.01M! ±(3.0% reading + 5 digits)

40nF 0.01nF ±(5.0% reading + 7 digits)

400nF 0.1nF ±(3.0% reading + 5 digits)

4µF 0.001µF

40µF 0.01µF

100µF 0.1µF ±(5.0% reading + 5 digits)

5.000Hz 0.001Hz

50.00Hz 0.01Hz

500.0Hz 0.1Hz

5.000kHz 0.001kHz

50.00kHz 0.01kHz

500.0kHz 0.1kHz

5.000MHz 0.001MHz

10.00MHz 0.01MHz

Sensitivity: 0.8V rms min. <100kHz; 5Vrms min > 100kHz.

0.1 to 99.9% 0.1% ±(1.2% reading + 2 digits) Duty Cycle

Pulse width: 100!s - 100ms, Frequency: 5Hz to 150kHz

-4 to 1382°F 1°F Temp

-20 to 750°C

-4 to 518°F 1°F Temp

-20 to270°C

converter.

1°C

1°C

±(1.0% reading + 2 digits)

±(3.5% reading + 5 digits)

±(1.5% reading + 5 digits)

±(1.2% reading + 2 digits)

±(1.5% reading + 4 digits)

±(3.0% reading + 3 digits)

(probe accuracy not included)

±2.0% reading or ±2°C, ± 4 °F

8

Diode Test Test current of 0.3mA maximum,

open circuit voltage 1.5V DC typical

Continuity Check Audible signal will sound if the

resistance is less than 150!
(approx.), test current <0.7mA

Temperature Sensor Requires type K thermocouple
IR Spectral response 6 to 16!m
IR Emissivity 0.95 fixed
IR distance ratio 8:1
Input Impedance >7.5M" (VDC & VAC)
AC Response True rms
ACV Bandwidth 50Hz to 1kHz
Display 4000 count backlit liquid crystal
Overrange indication “OL” is displayed
Auto Power Off 15 minutes (approximately)
Polarity Automatic (no indication for

positive); Minus (-) sign for negative .

Measurement Rate 2 times per second, nominal
Low Battery Indication “ ” is displayed if battery voltage

drops below operating voltage

Battery one 9 volt (NEDA 1604) battery
Fuses mA, !A ranges; 0.5A/250V fast blow

A range; 20A/250V ceramic fast
blow

Operating Temperature 32
Storage Temperature -4

o

F to 122oF (0oC to 50oC)

o

F to 140oF (-20oC to 60oC)

Relative Humidity <70% operating, <80% storage
Operating Altitude 7000ft. (2000) meters maximum.
Weight 0.753lb (342g) (includes holster).
Size 7.36” x 3.2” x 2.0” (187 x 81 x

50mm) (includes holster)

Safety For indoor use and in accordance

with the requirements for double
insulation to IEC1010-1 (1995):
EN61010-1 (1995) Overvoltage
Category III, Pollution Degree 2.

9

BATTERY INSTALLATION

WARNING: To avoid electric shock, disconnect the test leads

from any source of voltage before removing the battery cover.

1. Disconnect the test leads from the meter.

2. Remove the rear battery cover by removing the two screws

using a Phillips head screwdriver.

3. Insert the battery into battery clips, observing the correct

polarity.

4. Put the battery cover back in place and secure with the two

screws.

WARNING: To avoid electric shock, do not operate the meter
until the battery cover is in place and fastened securely.

NOTE: If your meter does not work properly, check the fuses and

batteries to make sure that they are still good and that they
are properly inserted.

10

OPERATING INSTRUCTIONS

WARNING: Risk of electrocution. High-voltage circuits, both AC

and DC, are very dangerous and should be measured with great
care.

1. ALWAYS turn the function switch to the OFF position when the

meter is not in use.

2. If “OL” appears in the display during a measurement, the value

exceeds the range you have selected. Change to a higher range.

NOTE: On some low AC and DC voltage ranges, with the test

leads not connected to a device, the display may show a
random, changing reading. This is normal and is caused by
the high-input sensitivity. The reading will stabilize and give
a proper measurement when connected to a circuit.

DC VOLTAGE MEASURE MENTS

CAUTION: Do not measure DC voltages if a motor on the

circuit is being switched ON or OFF. Large voltage surges may
occur that can damage the meter.

1. Set the function switch to the V

position.

2. Insert the black test lead banana

plug into the negative (COM) jack.
Insert the red test lead banana
plug into the positive (V) jack.

3. Touch the black test probe tip to

the negative side of the circuit.
Touch the red test probe tip to the
positive side of the circuit.

4. Read the voltage in the display.

11

AC VOLTAGE MEASURE MENTS

AC VOLTAGE: The probe tips may not be long enough to

contact the live parts inside some 240V outlets for appliances
because the contacts are recessed deep in the outlets. As a
result, the reading may show 0 volts when the outlet actually
has voltage on it.

WARNING: To avoid electric shock, make sure the probe tips
are touching the metal contacts inside the outlet before
assuming no voltage is present

CAUTION: Do not measure AC voltages if a motor on the
circuit is being switched ON or OFF. Large voltage surges may
occur that can damage the meter.

1. Set the function switch to the V

position.

2. Press the SELECT button to

indicate “AC” on the display.

3. Insert the black test lead banana

plug into the negative (COM) jack.
Insert red test lead banana plug into
the positive (V) jack.

4. Touch the black test probe tip to the

negative side of the circuit.
Touch the red test probe tip to the
positive side of the circuit.

5. Read the voltage in the display.

12

DC CURRENT MEASURE MENTS

CAUTION: Do not make current measurements on the 20A

scale for longer than 30 seconds. Exceeding 30 seconds may
cause damage to the meter and/or the test leads.

1. Insert the black test lead banana plug into the negative (COM)

jack.

2. For current measurements up

to 4000!A DC, set the
function switch to the !A
position and insert the red test
lead banana plug into the
(!A/mA) jack.

3. For current measurements up

to 400mA DC, set the function
switch to the mA position and
insert the red test lead
banana plug into the (!A/mA)
jack.

4. For current measurements up

to 20A DC, set the function
switch to the A range and
insert the red test lead
banana plug into the (20A)
jack.

5. Remove power from the circuit under test, then open up the

circuit at the point where you wish to measure current.

6. Touch the black test probe tip to the negative side of the circuit.

Touch the red test probe tip to the positive side of the circuit.

7. Apply power to the circuit.

8. Read the current in the display.

13

AC CURRENT MEASURE MENTS

WARNING: To avoid electric shock, do not attempt to

measure AC A in circuits that have voltages which exceed
250V AC.

CAUTION: Do not make current measurements on the 20A
scale for longer than 30 seconds. Exceeding 30 seconds may
cause damage to the meter and/or the test leads.

1. Insert the black test lead banana plug into the negative (COM)

jack.

2. For current measurements up

to 4000!A AC, set the function
switch to the !A position and
insert the red test lead banana
plug into the (!A/mA) jack.

3. For current measurements up

to 400mA AC, set the function
switch to the mA position and
insert the red test lead banana
plug into the (!A/mA) jack.

4. For current measurements up

to 20A AC, set the function
switch to the A range and
insert the red test lead banana
plug into the (20A) jack.

5. Press the SELECT button to

indicate “AC” on the display.

6. Remove power from the circuit under test, then open up the

circuit at the point where you wish to measure current.

7. Touch the black test probe tip to the negative side of the circuit.

Touch the red test probe tip to the positive side of the circuit.

8. Apply power to the circuit.

9. Read the current in the display.

14

RESISTANCE MEASUREMENTS

WARNING: To avoid electric shock, disconnect power to the

unit under test and discharge all capacitors before taking any
resistance measurements. Remove the batteries and unplug
the line cords.

1. Set the function switch to the

! position.

2. Insert the black test lead banana

plug into the negative (COM) jack
Insert the red test lead banana
plug into the positive ! jack.

3. Touch the test probe tips across

the circuit or part under test. It is
best to disconnect one side of the
part under test so the rest of the
circuit will not interfere with the
resistance reading.

4. Read the resistance in the display.

15

CONTINUITY CHECK

WARNING: To avoid electric shock, never measure continuity

on circuits or wires that have voltage on them.

1. Set the function switch to the

! position.

2. Insert the black lead banana plug

into the negative (COM) jack
Insert the red test lead banana
plug into the positive (!) jack.

3. Press the SELECT button to

indicate !!!!on the display

4. Touch the test probe tips to the

circuit or wire you wish to check.

5. If the resistance is less than

approximately 150!, the audible
signal will sound. If the circuit is
open, the display will indicate “OL”.

DIODE TEST

1. Set the function switch to the

! position

2. Insert the black test lead banana

plug into the negative CO M jack
and the red test lead banana plug
into the positive diode jack.

3. Press the SELECT button to

indicate !!!!!!on the display.

4. Touch the test probes to the

diode under test. Forward voltage
will typically indicate 0.400 to

0.700mV. Reverse voltage will
indicate “OL”. Shorted devices
will indicate near 0mV. Shorted
devices will indicate near 0mV
and an open device will indicate
“OL” in both polarities.

16

CONTACT TEMPERA TURE MEASUREMENTS

1. Set the function switch to the (K) ºF or ºC position.

2. Insert the

Temperature Probe
into the input jacks,
making sure to
observe the correct
polarity.

3. Touch the

Temperature Probe
head to the part
whose temperature
you wish to
measure. Keep the
probe touching the
part under test until
the reading
stabilizes (about 30
seconds).

4. Read the

temperature in the display.

Note: The temperature probe is fitted with a type K mini connector.

A mini connector to banana connector adaptor is supplied
for connection to the input banana jacks.

17

NON-CONTACT TEMPERATURE MEASUREMENTS

1. Set the function switch to the Non-Contact (IR) ºF or ºC position.

2. Point the meter at the surface to be measured.

3. If needed, press the red IR Laser Pointer button to locate the

exact spot being measured.

4. The area of the surface to be measured must be larger than the

spot size as determined by the distance to spot size
specification.

5. Read the temperature in the display.

WARNING: Do not directly view or direct the laser pointer
at an eye. Low power visible lasers do not normally present a

hazard, but may present some potential for hazard if viewed
directly for extended periods of time.

18

CAPACITANCE MEASUR EMENTS

WARNING: To avoid electric shock, disconnect power to the

unit under test and discharge all capacitors before taking any
capacitance measurements. Remove the batteries and unplug
the line cords.

1. Set the function switch to the

CAP position.

2. Insert the black test lead banana

plug into the negative (COM)
jack.
Insert the red test lead banana
plug into the positive (CAP) jack.

3. Touch the test leads to the

capacitor to be tested.

4. Read the capacitance value in

the display

19

FREQUENCY MEASURE MENTS

1. Set the function switch to the

“FREQ %” position.

2. Insert the black lead banana

plug into the negative COM
jack and the red test lead
banana plug into the positive
Hz jack.

3. Touch the test probe tips to the

circuit under test.

4. Read the frequency on the

display.

% DUTY CYCLE

1. Set the function switch to the

“FREQ %” position.

2. Insert the black lead banana

plug into the negative COM
jack and the red test lead
banana plug into the positive Hz jack.

3. Press the SELECT key momentarily

to select % in the display.

4. Touch the test probe tips to the circuit

under test.

5. Read the % duty cycle on the display.

20

AUTORANGE/MANUAL RANGE SELECTION

When the meter is first turned on, it automatically goes into
AutoRanging. This automatically selects the best range for the
measurements being made and is generally the best mode for
most measurements. For measurement situations requiring that
a range be manually selected, perform the following:

1. Press the RANGE key. The AUTO display indicator will turn

off.

2. Press the RANGE key to step through the available ranges

until you select the range you want.

3. To exit the Manual Ranging mode and return to AutoRanging,

press and hold the RANGE key for 2 seconds.

Note: Manual ranging does not apply for the Capacitance,

Frequency and Temperature functions.

RELATIVE MODE

The relative measurement feature allows you to make
measurements relative to a stored reference value. A reference
voltage, current, etc. can be stored and measurements made in
comparison to that value. The displayed value is the difference
between the reference value and the measured value.

1. Perform the measurement as described in the operating

instructions.

2. Press the REL button to store the reading in the display and

the "REL" indicator will appear on the display.

3. The display will now indicate the difference between the

stored value and the measured value.

4. Press the REL button to exit the relative mode.
Note: The Relative function does not operate in the Frequency

function.

DISPLAY BACKLIGHT

Press and hold the HOLD key for >1 second to turn on or off the
display backlight function.

Note: The HOLD feature will activate when the Backlight is

turned on. Press the HOLD key again to exit Data Hold.

21

DATA HOLD

The hold function freezes the reading in the display. Press the
HOLD key momentarily to activate or to exit the hold function.
Note: In the Frequency mode, Data Hold will function only while
a frequency is applied.

AUTO POWER OFF

The auto off feature will turn the meter off after 20 minutes.

LOW BATTERY INDICATION

The icon will appear in the lower left corner of the display
when the battery voltage becomes low. Replace the battery
when this appears.

WRONG CONNECTION IND ICATION

The icon will appear in the upper right corner of the display
and the buzzer will sound whenever the positive test lead is
inserted into the 20A or uA/mA input jack and a non-current
function is selected. If this occurs, turn the meter off and reinsert
the test lead into the proper input jack for the function selected.

22

MAINTENANCE

WARNING: To avoid electric shock, disconnect the test leads

from any source of voltage before removing the back cover or
the battery cover.

WARNING: To avoid electric shock, do not operate your meter
until the battery cover is in place and fastened securely.

This multimeter is designed to provide years of dependable service,
if the following care instructions are performed:

1. KEEP THE METER DRY. If it gets wet, wipe it off.

2. USE AND STORE THE METER IN NORMAL

TEMPERATURES. Temperature extremes can shorten the life
of the electronic parts and distort or melt plastic parts.

3. HANDLE THE METER GENTLY AND CAREFULLY. Dropping

it can damage the electronic parts or the case.

4. KEEP THE METER CLEAN. Wipe the case occasionally with a

damp cloth. DO NOT use chemicals, cleaning solvents, or
detergents.

5. USE ONLY FRESH BATTERI ES OF THE RECO MMENDED

SIZE AND TYPE. Remove old or weak batteries so they do not
leak and damage the unit.

6. IF THE METER IS TO BE STORE D FOR A LONG P ERIOD

OF TIME, the batteries should be removed to prevent damage
to the unit.

UL LISTED

The UL mark does not indicate that this product has been
evaluated for the accuracy of its readings.

23

BATTERY REPLACE MENT

WARNING: To avoid electric shock, disconnect the test leads

from any source of voltage before removing the battery cover.

1. When the battery becomes exhausted or drops below the

operating voltage, “ ” will appear in the left-hand side of the
LCD display. The battery should be replaced.

2. Follow instructions for installing batteries. See the Battery

Installation section of this manual.

3. Dispose of the old batteries properly.

WARNING: To avoid electric shock, do not operate your meter
until the battery cover is in place and fastened securely.

NOTE: If your meter does not work properly, check the fuses and
batteries to make sure that they are still good and that they are
properly inserted.

24

FUSE REPLACEMENT

WARNING: To avoid electric shock, disconnect the test leads

from any source of voltage before removing the battery cover.

1. Disconnect the test leads from the meter.

2. Remove the protective rubber holster.

3. Remove the battery cover (two “B” screws).

4. Disconnect and remove the battery.

5. Remove the four “A” screws securing the rear cover.

6. Remove the rear cover.

7. Lift the center circuit board straight up from the connectors to

gain access to the fuse holders.

8. Gently remove the old fuse and install the new fuse into the

holder.

9. Always use a fuse of the proper size and value (0.5A/250V fast

blow for the 400mA range, 20A/250V fast blow for the 20A
range).

10. Align the center board with the connectors and gently press

into place.

11. Replace and secure the rear cover, battery, battery cover and

screws.

WARNING: To avoid electric shock, do not operate your meter
until the battery cover is in place and fastened securely.

25

TROUBLESHOOTING

There may be times when your meter does not operate properly.
Here are some common problems that you may have and some
easy solutions to them.

Meter Does Not Operate:

1. Always read all the instructions in this manual before use.

2. Check to be sure the battery is properly installed.

3. Check to be sure the battery is good.

4. If the battery is good and the meter still doesn’t operate, check

to be sure that both ends of the fuse are properly installed.

If You Do Not Understand How the Meter Works:

1. Purchase “Multitesters and Their Use for Electrical Testing”,

(Item No. 82303).

2. Call our Customer Service Line 1-888-326-1006.

SERVICE AND PARTS

Item Number Description

82376 Fuse kit
93894 9V battery
82378 Set of black and red Test Leads
81079-D Replacement battery cover
81079-C Front Cover
81079-CS Rear cover screws
82377 Thermocouple probe

For replacement parts shipped directly to your home

Call 9 am – 5 pm Eastern Time, M - F

1-888-326-1006

26