Craftsman 81079 User manual

Owner's Manual
True RMS Multimeter
with IR Thermometer
Model No.
81079
© Sears, Roebuck and Co., Hoffman Estates, IL 60179 U.S.A.
www.craftsman.com 062006
•Safety
•Operation
•Maintenance
•Español
CAUTION: Read, understand and
follow Safety Rules and Operating
Instructions in this manual before
using this product.

2
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

3
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.

4
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: Input Limits
Function Maximum Input
V DC or V AC 600V DC/AC, 200Vrms on 400mV
range
mA AC/DC 500mA 250V fast acting fuse
A AC/DC 20A 250V fast acting fuse(30
seconds max every 15 minutes)
Frequency, Resistance,
Capacitance, Duty Cycle,
Diode Test, Continuity
250Vrms for 15sec max
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

5
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.
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.
WARNING
CAUTION
MAX
600V

6
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 (10-9)
(capacitance)
micro (10-6) (amps, cap)
m milli (10-3) (volts, amps) A Amps
k kilo (103) (ohms) F Farads (capacitance)
M mega (106) (ohms) Ohms
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

7
SPECIFICATIONS
Function Range Resolution Accuracy
400mV 0.1mV ±(0.3% reading + 2 digits)
4V 0.001V
40V 0.01V
400V 0.1V
±(0.5% reading + 2 digits)
DC
Voltage
600V 1V ±(0.8% reading + 3 digits)
50 to 400Hz 400Hz to 1kHz
400mV 0.1mV ±(1.5% reading
+ 15 digits) ±(2.5% reading + 15digits)
4V 0.001V
40V 0.01V
400V 0.1V
±(1.5% reading
+ 6 digits) ±(2.5% reading + 8 digits)
AC
Voltage
600V 1V ±(1.8% reading
+ 6 digits) ±(3% reading + 8 digits)
400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
±(1.5% reading + 3 digits)
4A 0.001A
DC
Current
20A 0.01A ±(2.5% reading + 5 digits)
50 to 400Hz 400Hz to 1KHz
400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
±(1.8% reading
+ 8 digits) ±(3.0% reading + 7 digits)
4A 0.001A
AC
Current
20A 0.01A ±(3.0% reading
+ 8 digits) ±(3.5% reading + 10 digits)
NOTE: Accuracy is stated at 65oF to 83oF (18oC to 28oC) and less
than 75% RH.

8
Function Range Resolution Accuracy
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
±(1.0% reading + 2 digits)
Resistance
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 ±(3.5% reading + 5 digits)
C
apacitance
100µF 0.1µF ±(5.0% reading + 5 digits)
5.000Hz 0.001Hz
50.00Hz 0.01Hz ±(1.5% reading + 5 digits)
500.0Hz 0.1Hz
5.000kHz 0.001kHz
50.00kHz 0.01kHz
500.0kHz 0.1kHz
±(1.2% reading + 2 digits)
5.000MHz 0.001MHz
10.00MHz 0.01MHz ±(1.5% reading + 4 digits)
Frequency
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°FTemp
(type-K) -20 to 750°C
1°C
±(3.0% reading + 3 digits)
(probe accuracy not included)
-4 to 518°F 1°FTemp
(IR) -20 to270°C
1°C ±2.0% reading or ±2°C, ±4 °F
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
converter.

9
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 32oF to 122oF (0oC to 50oC)
Storage Temperature -4oF 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.

10
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.

11
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 MEASUREMENTS
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.

12
AC VOLTAGE MEASUREMENTS
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.

13
DC CURRENT MEASUREMENTS
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 Arange 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.

14
AC CURRENT MEASUREMENTS
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 Aposition 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 Arange 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.

15
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.

16
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 COM 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.

17
CONTACT TEMPERATURE 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.

18
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.

19
CAPACITANCE MEASUREMENTS
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

20
FREQUENCY MEASUREMENTS
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.