Tenma 72-7228 User manual

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Digital Clamp meter
Model: 72-7228

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This meter is designed to meet IEC61010-1, 61010-2-032, and 61010-2-033 in
Pollution Degree 2, Measurement Category (CAT II 600V, CAT III 300V) and double
Insulation.
• Do not operate the meter or use test leads if they appear damaged, or if the meter
is not operating properly.
• There are no user-serviceable parts in this product. Refer servicing to qualied
personnel.
• Do not apply voltage between the COM and OHM terminals, while in the
resistance measuring state.
• Do not measure current with the test leads inserted into the voltage or OHM
terminals.
• To avoid electrical shock and personal injury, do not attempt to measure voltage
higher than 600V AC/DC, although the readings may be obtained.
• Do not expose the instrument to direct sunlight, extreme temperature or humidity.
• Before measuring current, check the fuses and turn the power to the circuit off
before connecting the meter to the circuit.
• To prevent damage to the meter, range or mode changes should not be made
during measurement.
• Disconnect circuit power and discharge all high voltage capacitors before testing
continuity. diode, resistance, capacitance or current.
• Do not use the meter around explosive gas or vapour.
• When using the test leads, keep your ngers behind the nger guards.
• Remove test leads from the meter before opening the meter case or battery door.
• Never operate the meter with the cover removed or the battery door open.
• Use only the test leads supplied or the protection may be impaired.
• Probe assemblies for mains measurements shall be rated as appropriate for
measurement category III according to IEC 61010-031 and shall have a voltage
rating of at least the voltage of the circuit to be measured.
• Replace the batteries as soon as the low battery indicator appears on the display.
• Remove dead batteries from the meter or if it is not going to be used for a long
time.
• Never dispose of batteries in a re, or attempt to recharge ordinary batteries.
• Before replacing the battery, turn off the meter and disconnect all the test probes.
• To prolong battery life turn off the meter after use.
SAFETY INFORMATION
Please read these instructions carefully before use and retain for future
reference.
WHAT’S INCLUDED
• Digital multimeter
• Storage case
• User manual
• Test leads
• 9V Battery (NEDA1604A or 6LF22)

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SYMBOL GUIDE
AC (Alternating Current)
DC (Direct Current)
AC or DC
Grounding
Double insulated
Warning
Low battery
Continuity buzzer
Diode
Fuse
Capacitance test
Conforms to European Union directives
FUNCTIONS
1. Hands guard: protects hands from touching the
dangerous area.
2. Trigger: press and release the trigger to open and
close the detector jaw.
3. Function buttons x 3
4. Input terminals
5. LCD Display
6. Range selector
7. Detector jaw: designed to pick up the AC current
owing through the conductor.
Setting Indicators Surge Indicator
Main Reading
Indicator
Mode Indicators
Negative
Indicator
Low Battery
Indicator
True RMS
Indicator

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OPERATING PARAMETERS
• Operating temperature: 23°C± 5°C
• Relative Humidity: ≤80%.
• Temperature Coefcient: 0.1× (specied accuracy)/1°C
DC VOLTAGE AUTO RANGING
Range Resolution Accuracy Overload Protection
6.600V 1mV
±(0.8%+1) 600V DC/AC
66.00V 10mV
600.0V 100mV
Note: The input impedance is 10MΩ.
AC VOLTAGE AUTO RANGING
Range Resolution Accuracy Overload Protection
6.600V 1mV
±(1.2%+5) 600V DC/AC66.00V 10mV
600.0V 100mV
Notes:
• Input Impedance: 10MΩ
• Frequency Response: 40Hz~400Hz
• Change to AC:
Combine AC and True RMS response method. Input sine wave to adjust.
Non sine wave signals must be adjusted based on the following data:
Peak factor: 1.4~2.0, add 1.0% to the stated accuracy
Peak factor: 2.0~2.5, add 2.5% to the stated accuracy
Peak factor: 2.5~3.0, add 4.0% to the stated accuracy.
RESISTANCE
Range Resolution Accuracy Overload Protection
660.0Ω 100mΩ ±(1.2%+2)
250VAC
6.600kΩ 1Ω
±(1%+2)66.00kΩ 10Ω
660.0kΩ 100Ω
6.600MΩ 1kΩ ±(1.2%+2)
66.00MΩ 10kΩ ±(1.5%+2)
Range Resolution Accuracy Overload Protection
1mV
0.5V~0.8V
(Open circuit voltage
approx. 3.0V)
250VAC
DIODE AND CONTINUITY

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Notes:
• Input Sensitivity (a) as follows:
When a ≤10Hz: the meter does not respond
When 10Hz < a ≤100kHz: ≥300mV rms
When a >100kHz: ≥600mV rms
Range Resolution Accuracy Overload Protection
660.0Ω 0.1Hz
±(0.1%+3) 250VAC
6.600kΩ 0.001kHz
66.00kΩ 0.01kHz
660.0kΩ 0.1kHz
6.600MΩ 0.001MHz
66.00MΩ 0.01MHz
Range Resolution Accuracy Overload Protection
0.1Ω
Around ≤30Ω, the
buzzer will sound.
(Open circuit voltage
approx. –1.2V)
250VAC
Notes:
• The open circuit voltage is about 0.45V.
• The buzzer may sound when the resistance of a circuit under test is 30Ω~100Ω.
• The buzzer does not sound when the resistance of a circuit under test is higher
than 100Ω.
FREQUENCY
DUTY CYCLE
DC CURRENT
AC CURRENT
Range Resolution Accuracy Overload Protection
0.1%~99.9% 0.1% For reference only 250VAC
Range Resolution Accuracy Overload Protection
66.00A 0.01A ±(2%+40) 250VAC
1000A 1A ±(2%+8)
Range Resolution Accuracy Frequency
response
Overload
Protection
66.00A 0.01A ±(2%+40) 50Hz ~ 60Hz 250VAC
1000A 1A ±(2%+8)
Warning:
• The operating temperature must be 0°C ~ 40°C when measuring current.

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Measuring Resistance
Warning
• To avoid damage to the meter or to the devices
under test, disconnect circuit power and
discharge all the high-voltage capacitors before
measuring resistance.
The resistance ranges are 660Ω, 6.6kΩ, 660kΩ,
6.6MΩ and 66MΩ.
• To measure the resistance, perform the following
steps:
1. Insert the red test lead into the VΩHz
terminal and the black test lead into the COM
terminal.
2. Turn the range selector to Ω. Press
SELECT to select Ω mode.
OPERATION
Measuring DC/AC Voltage
Warning
• To avoid damage to the meter, or risk of personal injury, do not attempt to measure
higher than 600V.
• The DC and AC voltage ranges are 600V, 66V and 6.6V.
• To measure DC or AC voltage, perform the following steps:
1. Insert the red test lead into the VΩHz terminal and the black test lead into the
COM terminal.
2. Turn the range selector to V
DC measurement mode and auto ranging is a default. Press SELECT to
switch to AC measurement mode.
3. Press Hz button to measure frequency or duty cycle, but the frequency or
duty cycle readings obtained from this range are only for reference.
4. Connect the test probes with the object being measured. The measured value
shows on the display.
• When voltage measurement has been completed, disconnect the test leads from
the circuit under test and remove them from the input terminals.

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Testing Diodes
Warning
• To avoid damage to the meter or to the devices under test, disconnect circuit
power and discharge all the high-voltage capacitors before testing diodes.
• Use the diode test mode to check diodes, transistors and other semiconductor
devices. In diode test mode, a current is sent through the semiconductor junction
and the voltage drop across the junction is measured.
• To test a diode out of a circuit, perform the following steps:
1. Insert the red test lead into the VΩHz terminal
and the black test lead into the COM terminal.
2. Turn the range selector to Ω. Press
SELECT to switch to diode measurement
mode.
3. For forward voltage drop readings on any
semiconductor component, connect the red
test probe to the component’s anode and the
black test probe to the cathode.
Notes:
• In a circuit, a good diode should still produce
a forward voltage drop reading of 0.5V to 0.8;
however, the reverse voltage drop reading can vary
depending on the resistance of other pathways
between the probe tips.
• The unit of diode is volt (V), displaying the forward voltage drop readings.
• To obtain a more precise reading, you could remove the object being measured
from the circuit when measuring.
• When diode testing has been completed, disconnect the test leads from the circuit
under test, and remove them from the input terminals.
3. Connect the test probes with the object being measured. The measured value
shows on the display.
Notes:
• Removing the object under test from its circuit will allow more accurate
measurement.
• When resistance measurement has been completed, disconnect the test leads
from the circuit under test, and remove them from the input terminals.
Measuring Continuity
• To test continuity, perform the following steps:
1. Insert the red test lead into the VΩHz terminal
and the black test lead into the COM terminal.
2. Turn the range selector to Ωand press
SELECT button to choose the continuity
measurement mode.
• The buzzer will sound if the resistance of a circuit
under test is less than 30Ω.
• The buzzer may sound if the resistance of a circuit
under test is between 30Ω and 100Ω.

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Measuring Frequency
• The frequency ranges are 660Hz, 6.6kHz, 66kHz,
6.6MHz and 66MHz.
• To test frequency, perform the following steps:
1. Insert the red test lead into the VΩHz terminal
and the black test lead into the COM terminal.
2. Turn the range selector to %Hz and
press SELECT button to choose the Hz
measurement mode.
3. Connect the test leads across the object
being measured.
• When continuity testing has been completed,
disconnect the test leads from the circuit under test
and remove the test leads from the input terminals.
Duty Cycle Measurement
• The duty cycle range is: 0.1%~99.9%.
• To measure duty cycle, perform the following steps:
1. Insert the red test lead into the VΩHz terminal
and the black test lead into the COM terminal.
2. Turn the range selector to %Hz and
press SELECT button to choose the %
measurement mode.
3. Connect the test leads across the object being
measured.
• When duty cycle measurement has been
completed, disconnect the test leads from the
circuit under test and remove the test leads from
the input terminals.
• The buzzer does not sound if the resistance of a circuit under test is higher than
100Ω.
• When continuity testing has been completed, disconnect the test leads from the
circuit under test and remove the test leads from the input terminals.
Measuring DC Current
Warning
• To avoid electric shock, never measure current while the test leads
are inserted into the input terminals.
• The measurement ranges of current are 66A and 1000A.
• To measure current, do the following:
1. Set the range selector to 66A or 1000A
2. Press the trigger to open the detector jaw.
3. Center the conductor within the detector jaw then release
the trigger gently until fully closed. Make sure the conductor
remains centrally through the jaws during measurement.

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• The measured value shows on the display, it is an effective value of sine wave
(mean value response).
Note:
• If the meter does not display 00.00 when 66A range, press ZERO to reset. The
ZERO button is then inoperative.
• When current measurement has been completed, press the jaw lever to open the
jaw and remove the conductor from the meter.
Sleep Mode
• To preserve battery life, the meter automatically turns off after 15 minutes of
inactivity.
• The meter beeps 3 times one minute before entering sleep mode followed by one
long beep just before entering sleep mode.
• The meter can be activated by turning the rotary switch or by pressing any function
button when the meter will display the measurement value shown before entering
sleep mode.
• To disable the sleep mode feature, pressand hold either MAX/MIN, LIGHT or Hz
buttons while turning on the meter.
Measuring AC Current
Warning
• To avoid electric shock, never measure current while the test leads
are inserted into the input terminals.
• The measurement ranges of current are 66A~ and 1000A~.
• To measure current, do the following:
1. Set the range selector to 66A~ or 1000A~
2. Press the trigger to open the detector jaw.
3. Center the conductor within the detector jaw then release
the trigger gently until fully closed. Make sure the conductor
remains centrally through the jaws during measurement.
• When the measuring current >1A, press Hz button to step
through AC current, frequency and duty cycle measurement
mode.
Note: the frequency or duty cycle readings obtained from this range is only for
reference.
• To measure surge current while in this AC measurement mode and with
the conductor still within the jaws do the following:
1. Set the rotary switch to 1000A~ .
2. Press SELECT when the meter displays the minimum readings. The
meter then displays “-----’’ indicating it is ready to carry out surge
current measurement.
3. Turn on the electrical equipment at this time to measure the
momentary start up current.
Note: When the meter is set to surge current measurement, it is locked in the
highest measurement range.

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Specications
A. General Specications:
Maximum voltage including transient
overvoltage between any terminals and
ground:
500V rms.
Auto Polarity Display: 3 5/6 digits LCD display,
Maximum display 6666
Overload : Display OL or –OL
Low battery : Display
Measurement Speed : Updates 3 times/second.
Measurement Deviation : When the conductor being measured is not
placed centrally through the jaws during
AC current measurement, it will cause 1%
reading deviation.
Max. Jaw Size : 2.17” (55mm) diameter.
Projected Max.Current conductor size : 1.77” (45mm) diameter.
Power : 9V battery (6LF22 1604A) x 2off
Battery Life : typically 150hours (alkaline batteries)
Dimensions (H x W x L) : 105.5 x 285.3 x 44.5mm.
Weight : Approximate 533g (battery included)
B. Environmental Restrictions:
Altitude : Operating: 2000m
Storage: 10000m
Temperature and humidity: Operating: 0oC~30oC (≤80% R.H)
30oC~40oC ( ≤75%R.H)
40oC~50oC (≤45%R.H)
Storage: -20oC~+60oC (≤80%R.H)

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MAINTENANCE
Cleaning
• Clean the meter with a clean, soft cloth.
• Do not use any chemicals, abrasives or solvents that could damage the meter.
• Clean the terminals with a mild detergent, as dirt on the terminals can affect
readings.
Replacing the battery
• When the meter displays the low battery
symbol, replace the battery immediately in
order to maintain normal operation.
• Disconnect and remove all test probes from
any live source and the meter.
• Open the battery cover on the rear case
with a screwdriver.
• Remove the old battery and t a new 9V
battery into the battery holder.
• Replace the battery cover.
Screw
Battery

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INFORMATION ON WASTE DISPOSAL FOR CONSUMERS OF
ELECTRICAL & ELECTRONIC EQUIPMENT
These symbols indicate that separate collection of Waste Electrical and Electronic Equipment
(WEEE) or waste batteries is required. Do not dispose of these items with general household
waste. Separate for the treatment, recovery and recycling of the materials used. Waste batteries
can be returned to any waste battery recycling point which are provided by most battery retailers.
Contact your local authority for details of the battery and WEEE recycling schemes available in
your area.
Made in China. PR2 9PP
Man Rev 1.0