Tenma 72-7224 User manual

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Digital Clamp Meter
Model: 72-7224 & 72-7226

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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.
• 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 mix old and new batteries together, or different types of batteries.
• 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
• User manual
• Test lead
• One 9V battery
• Carrying bag

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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
Application around and removal from UNINSULATED HAZARDOUS LIVE
conductors is permitted.
Conforms to European Union directives
This symbol signies the product complies with both USA and Canada
requirements.
FUNCTIONS
1. Input terminals
2. LCD Display
3. Function buttons x 3
4. Range selector
5. Trigger: press and release the trigger to open and
close the detector jaw.
6. Hands guard: protects hands from touching the
dangerous area.
7. Detector jaw: designed to pick up the AC and DC
current owing through the conductor. It transfers
current to voltage. The tested conductor must pass
centrally through the jaw.

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OPERATING PARAMETERS
• Operating temperature: 23°C± 5°C
• Relative Humidity: ≤85%.
• Temperature Coefcient: 0.1× (specied accuracy)/1°C
DC VOLTAGE
Range Resolution Accuracy Overload Protection
400.0mV 0.1mV ±(0.8%+3)
600V DC/AC
4.000V 1mV
±(0.8%+1)40.00V 10mV
400.0V 100mV
600V 1V ±(1%+3)
Note: The input impedance is 10MΩ.
AC VOLTAGE
Range Resolution Accuracy Overload Protection
4.000V 1mV
±(1%+5) 600V DC/AC 40.00V 10mV
400.0V 100mV
600V 1V ±(1.2%+5)
Notes:
• Input Impedance: 10MΩ
• Frequency Response: 40Hz~400Hz
• AC conversion type: Average-responded, calibrates the reading to be RMS by sine
wave input.
RESISTANCE
Range Resolution Accuracy Overload Protection
400.0Ω 100mΩ ±(1.2%+2)
600Vp
4.000kΩ 1Ω
±(1%+2)40.00kΩ 10Ω
400.0kΩ 100Ω
4.000MΩ 1kΩ ±(1.2%+2)
40.00MΩ 10kΩ ±(1.5%+2)

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Range Resolution Accuracy Overload Protection
1mV Displays approximate
forward voltage drop 600Vp
DIODE AND CONTINUITY
Note: The open circuit voltage is about 1.48V.
Range Resolution Accuracy Overload Protection
100mΩ When ≤10Ω, the
buzzer beeps. 600Vp
Notes:
• The open circuit voltage is about 0.45V.
• The buzzer may beep when the resistance of a circuit under test is 10Ω~100Ω.
• The buzzer does not beep when the resistance of a circuit under test is higher
than 100Ω.
FREQUENCY
Range Resolution Accuracy Overload Protection
10Hz 0.001Hz
±(0.1%+3) 600Vp
100Hz 0.01Hz
1kHz 0.1Hz
10kHz 1Hz
100kHz 10Hz
1MHz 100Hz
10MHz 1kHz For reference only
Notes:
• Input Sensitivity:
• ≤100kHz, ≥300mVrms
• >100kHz, ≥600mVrms
• >1MHz, ≥800mVrms
• Input Amplitude at:
• 10Hz~100kHz: 30Vrms ≥ a ≥ 300mVrms
• 100kHz~10MHz: 30Vrms ≥ a ≥ 600mVrms
DUTY CYCLE
Range Resolution Accuracy Overload protection
0.1%~99.9% 0.1% For reference only 600Vp

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DC CURRENT
Range Resolution Accuracy Overload Protection
40.00A 0.01A ±(2%+5) 400A DC/AC
400.0A 0.1A ±(2%+3)
Notes
• If the reading is positive, the current direction is from down to up (See Figure 10,
with the front panel facing up, and rear panel facing down).
• Do not release the jaw suddenly as the built-in Hall components are very sensitive
to magnetic force, heat and mechanical stress, any shock will cause read errors.
• To measure DC current and obtain a more precise reading, perform the following
steps:
1. Hold the meter, and press the trigger to open the detector jaw. Center the
conductor within the detector jaw, then release the trigger gently until the
detector jaw is completely closed. Make sure the conductor to be measured
is placed at the center of the detector jaw, otherwise it will produce ±1.0%
measuring deviation based on the stated accuracy.
2. Open the jaw and remove the detector from the current conductor.
3. Press REL to display zero.
4. Repeat Step 1.
AC CURRENT
Range Resolution Accuracy Frequency
Response
Overload
Protection
40.00A 0.01A ±(2.5%+8) 50Hz~60Hz 400A DC/AC
400.0A 0.1A ±(2.5%+5)
Note:
• To measure AC current and obtain a more precise reading, perform the following
steps:
1. Hold the meter, and press the trigger to open the detector jaw. Center the
conductor within the detector jaw, then release the trigger gently until the
detector jaw is completely closed. Make sure the conductor to be measured
is placed at the center of the detector jaw, otherwise it will produce ±1.0%
measuring deviation based on the stated accuracy.
2. Open the jaw and remove the detector from the current conductor.
3. Press REL to display zero.
4. Repeat Step 1.

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OPERATION
Measuring DC/AC Voltage
• The DC voltage ranges are 400mV, 4V, 40V, 400V and 600V.
• The AC voltage ranges are 4V, 40V, 400V and 600V.
• To measure DC/AC voltage, perform the following steps:
1. Insert the red test lead into the Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the range selector to and DC measurement mode and auto
range are set as default. To measure
AC voltage press SELECT switch to AC
measurement mode, and press REL
to switch to manual range measurement
mode.
3. Connect the test probes with the object
being measured. The measured value
shows on the display.
Note:
• When a measurement has been completed,
disconnect the test probes from the circuit
under test, and remove the test leads from the
input terminals.
Measuring Resistance
• The resistance ranges are 400Ω, 4kΩ, 40kΩ, 400kΩ, 4MΩ and 40MΩ.
• To measure the resistance, perform the following steps:
1. Insert the red test lead into the Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the range selector to Ω. Press REL
to switch from auto range as default to
manual range during the measurement if
required.
3. Connect the test probes with the object
being measured. The measured value
shows on the display.
Notes:
• To obtain a more precise reading, you could
remove the object being measured from the
circuit when measuring.
• When a measurement has been completed,
disconnect the test probes from the circuit under
test, and remove the test leads from the input
terminals.

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DIODE CHECK
CONTINUITY CHECK
• 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.
• A good silicon junction drop is between 0.5V and 0.8V.
• To test a diode out of a circuit, perform the following steps,
1. Insert the red test lead into the Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the rotary switch to . Press
SELECT to switch from diode
measurement mode as default to continuity
measurement mode if needed.
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:
• To obtain a more precise reading, you could
remove the object being measured from the
circuit when measuring.
• When a measurement has been completed,
disconnect the test probes from the circuit
under test, and remove the test leads from the
input terminals.
• To test continuity, perform the following steps:
1. Insert the red test lead into the Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the rotary switch to and press SELECT button to choose the
measurement mode.
• The buzzer will sound if the resistance of a
circuit under test is less than 50Ω.
• The buzzer may sound if the resistance of a
circuit under test is between 50Ω and 100Ω.
• The buzzer does not sound if the resistance of
a circuit under test is higher than 100Ω.
Note:
• When a measurement has been completed,
disconnect the test probes from the circuit
under test, and remove the test leads from the
input terminals.

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FREQUENCY MEASUREMENT
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 Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the rotary switch to Hz and press
REL to select duty cycle measurement
mode.
3. Connect the test probes with the object
being measured. The measured value
shows on the display.
Note:
• When a measurement has been completed,
disconnect the test probes from the circuit
under test, and remove the test leads from the
input terminals.
• The frequency ranges are 10Hz, 100Hz, 1kHz, 10kHz, 100kHz, 1MHz and 10MHz.
• To measure frequency, perform the following steps:
1. Insert the red test lead into the Hz Duty% terminal and the black
test lead into the COM terminal.
2. Turn the rotary switch to Hz.
3. Connect the test probes with the object
being measured. The measured value
shows on the display.
Note:
• When a measurement has been completed,
disconnect the test probes from the circuit under
test, and remove the test leads from the input
terminals.

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DC/AC CURRENT MEASUREMENT
• The current ranges are 40.00 Aand 400.0 A
• To measure current, perform the following steps,
1. Turn the rotary switch to 40.00 Aor 400.0 Aand press SELECT to
switch between DC (as default) and AC measurement mode.
2. Press the trigger to open the detector jaw.
3. Centre the conductor within the detector
jaw, then release the trigger gently until the
detector jaw is completely closed. Make
sure the conductor to be measured is
placed centrally otherwise it will produce an
inaccurate measurement.
The meter can only measure one conductor
at a time. If more than one conductor
is measured, incorrect readings will be
displayed.
To obtain a positive reading when measuring
DC current, the current must flow in the
direction from the rear of the meter to the
front.
4. Do not release the jaw suddenly as the
built-in Hall components are very sensitive to
magnetic force, heat and mechanical stress, any shock could cause damage
and create read errors.
Notes:
• Press REL to subtract a stored value from the present measurement value,
then a differential measurement result is displayed.
• When a measurement has been completed, open the detector jaw and remove the
meter from the conductor.
• The operating temperature must be 0ºC ~40ºC when measuring current.
Change to AC:
Model: 72-7224:
• Change to AC by using average response method.
• Input sine wave, then adjust the reading until it is same as the effective value.
Model: 72-7726:
• Combine AC and True RMS response method. Input sine wave to adjust.
• Non sine wave must follow the data below to adjust:
• Peak factor: 1.4~2.0, add 1.0% on the stated accuracy.
• Peak factor: 2.0~2.5, add 2.5% on the stated accuracy.
• Peak factor: 2.5~3.0, add 4.0% on the stated accuracy.

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MAINTENANCE
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.
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.
Battery
Screw

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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