Tenma 72-7224 User manual

Digital Clamp Multimeters
72-7224 / 72-7226

Table of Contents
Overview
Inspection
Safety Information
Rules For Safe Operation
International Electrical Symbols
The Meter Structure
Rotary Switch
Function Buttons
Button Use
Display Symbols
Measurement Operation
A. DC/AC Voltage Measurement
B. Measuring Resistance
C. Testing Diodes
D. Testing for Continuity
E. Frequency Measurement
F. Duty Cycle Measurement
G. DC/AC Current Measurement
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Title Page
Model 72-7224 / 72-7226: OPERATING MANUAL
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Sleep Mode
Specifications
A. General Specifications
B. Environmental Requirements
Accuracy Specifications
A. DC Voltage
B. AC Voltage
C. Resistance
D. Diode Test
E. Continuity Test
F. Frequency
G. Duty Cycle
H. DC Current
I. AC Current
Maintenance
A. General Service
B. Replacing the Battery
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Title Page
Model 72-7224 / 72-7226: OPERATING MANUAL
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Overview
This Operating Manual covers information on safety and cautions. Please read the
relevant information carefully and observe all the Warnings and Notes strictly.
Warning
To avoid electric shock or personal injury, read the “Safety Information” and “Rules
for Safe Operation” carefully before using the Meter.
Digital Clamp Multimeter Models 72-7224 and 72-7226 (hereafter referred to as “the
Meter”) are 3 3/4 digits with precise operation, fashionable structure and highly reliable
measuring instrument. The Meter uses large scale of integrated circuit with double
integrated A/D converter as its core and has full range overload protection.
Both models measure AC/DC Voltage, AC/DC Current, Frequency, Duty Cycle,
Resistance, Diodes and Continuity, and also include Data Hold, Sleep Mode and
Relative Mode features.
Model 72-7226 also provides True RMS measurement.
Model 72-7224 / 72-7226: OPERATING MANUAL
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Inspection
Open the package case and take out the Meter. Check the following items carefully
to see if any items are missing or damaged.
Item Description Qty
1
2
3
4
English Operating Manual
Test Lead
Carrying Bag
9V Battery (NEDA1604, 6F22 or 006P)
1 piece
1 pair
1 piece
1 piece
In the event you find any items missing or damaged, please contact your dealer
immediately.
Model 72-7224 / 72-7226: OPERATING MANUAL
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Safety Information
This Meter complies with the standards IEC61010: in pollution degree 2, overvoltage
category (CAT. II 600V, CAT. III 300V) and double insulation.
CAT. II: Local level, appliance, PORTABLE EQUIPMENT etc., with smaller transient
overvoltages than CAT. III.
CAT. III: Distribution level, fixed installation, with smaller transient overvoltages than
CAT. IV
Use the Meter only as specified in this operating manual, otherwise the protection
provided by the Meter may be impaired.
In this manual, a Warning identifies conditions and actions that pose hazards to the
user, or may damage the Meter or the equipment under test.
A Note identifies the information that user should pay attention to.
International electrical symbols used on the Meter and in this Operating Manual are
explained on page 9.
Model 72-7224 / 72-7226: OPERATING MANUAL
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Rules For Safe Operation
Warning
To avoid possible electric shock or personal injury, and to avoid possible damage
to the Meter or to the equipment under test, adhere to the following rules:
Before using the Meter inspect the case. Do not use the Meter if it is damaged
or the case (or part of the case) is removed. Look for cracks or missing plastic.
Pay attention to the insulation around the connectors.
Inspect the test leads for damaged insulation or exposed metal. Check the test
leads for continuity. Replace damaged test leads with identical model number
or electrical specifications before using the Meter.
Do not apply more than the rated voltage, as marked on the Meter, between the
terminals or between any terminal and ground. If the value to be measured is
unknown, use the maximum measurement position and reduce the range step
by step until a satisfactory reading is obtained.
When measurement has been completed, disconnect the connection between
the test leads and the circuit under test, remove the test leads away from the
input terminals of the Meter and turn the Meter power off.
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The rotary switch should be placed in the correct position and no change of
range made during measurement, to prevent damage to the Meter.
Do not carry out the measurement when the Meter’s back case and battery
compartment are not closed to avoid electric shock.
Do not input higher than 600V between the two Meter’s input terminal to avoid
electric shock and damages to the Meter.
When working at an effective voltage over 60VDC or 30VAC RMS, special care
should be taken for there is danger of electric shock.
Use the proper terminals, function, and range for your measurements.
Do not use or store the Meter in an environment of high temperature, humidity,
explosive, inflammable and strong magnetic field. The performance of the Meter
may deteriorate after dampened.
When using the test leads, keep your fingers behind the finger guards.
Disconnect circuit power and discharge all high-voltage capacitors before testing
resistance, continuity and diode.
Replace the battery as soon as the battery indicator appears. With a low
battery, the Meter might produce false readings that can lead to electric shock
and personal injury.
When servicing the Meter, use only the same model number or identical electrical
specifications replacement parts.
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Model 72-7224 / 72-7226: OPERATING MANUAL
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The internal circuit of the Meter shall not be altered at will to avoid damage of
the Meter and any accident.
Soft cloth and mild detergent should be used to clean the surface of the Meter
when servicing. No abrasive and solvent should be used to prevent the surface
of the Meter from corrosion, damage and accident.
The Meter is suitable for indoor use.
Turn the Meter off when it is not in use and take out the battery when not using
for a long time.
Periodically check the battery as it may leak after some time. If leakage is apparent,
the battery should be immediately replaced to prevent damage to the
Meter.
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Model 72-7224 / 72-7226: OPERATING MANUAL
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International Electrical Symbols
AC (Alternating Current)
DC (Direct Current)
AC or DC
Ground
Double Insulated
Warning. Refer to the Operating Manual
Low Battery
Continuity Test
Diode
Fuse
Application around and removal from HAZARDOUS LIVE
conductors is permitted.
Conforms to Standards of European Union
Model 72-7224 / 72-7226: OPERATING MANUAL
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The Meter Structure (see figure 1)
(figure 1)
Input Terminals
LCD Display
Function Buttons
Rotary Switch
Trigger: press the lever to open the transformer
jaws. When the pressure on the lever is released,
the jaws will close.
Hand Guards: to protect user’s hand from touching
the dangerous area.
Transformer Jaw: designed to pick up the AC and
DC current flowing through the conductor. The
conductor under test should pass perpendicular
through the jaw.
1.
2.
3.
4.
5.
6.
7.
Model 72-7224 / 72-7226: OPERATING MANUAL
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Rotary Switch
The following table provides information regarding the Rotary Switch positions.
Rotary Switch Position Power is turned off
AC or DC voltage measurement
Resistance measurement
: Diode test
: Continuity test
Frequency Measurement and Duty
Measurement
AC and DC current measurement range
Function
OFF
V
Hz / Duty%
40A 400A
&
/
Model 72-7224 / 72-7226: OPERATING MANUAL
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Function Buttons
The following table provides information regarding the rotary switch positions.
Button Operation Performed
Press HOLD to enter the Hold mode in any mode, the Meter will
beep to confirm.
Press HOLD again to exit the Hold mode, the Meter will again beep
to confirm.
At and range:
The Meter is defaults to auto ranging mode. Press the REL key to
select manual ranging mode.
When the Meter is at manual ranging mode, press to step down
the range.
At range:
Press to enter the REL mode.
It subtracts a stored value from the present measurement value
and displays a result.
At Hz/Duty% range:
Press to switch between Hz measurement mode and Duty %
measurement mode.
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HOLD
REL V
A
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Button Operation Performed
SELECT Press SELECT button to select the alternate functions marked in
blue colour on the Meter’s faceplate including , ,
40 , and 400 .
If the meter enters sleep mode, press and hold the SELECT button
to reactivate meter.
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A A
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Function Button Use
Not every function button is used in every rotary switch position. The table below
indicates which button can be used in which switch position.
Rotary Switch
Positions Function Buttons
SELECT REL HOLD
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N/A
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N/A
N/A
V
Hz / Duty%
40A
400A
/
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Display Symbols (see figure 2)
(figure 2)
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1
2
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Number Meaning
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AC
DC
Symbol Indicator for AC voltage or current
Indicator for DC voltage
The battery is low.
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.
The Meter is in the auto range mode in which the Meter
automatically selects the range with the best resolution.
Diode test.
The continuity buzzer is on
Indicator for Duty.
Data hold is active
Indicator for REL mode
%
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Number Meaning
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,k ,M
Hz
A
mV, V
TRMS
OL
Symbol : Ohm. The unit of resistance.
k : Kilohm. 1x103 or 1000 ohms
M : Megohm. 1x106 or 1,000,000 ohms
The unit of Frequency
Amperes (amps). The unit of current.
Volts. The unit of voltage.
mV: Millivolt. 1x10-3 or 0.001 volts
Indicates negative reading
Indicator for TRMS mode
The input value is too large for the selected range
Model 72-7224 / 72-7226: OPERATING MANUAL
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Measurement Operation
A. DC/AC Voltage Measurement (see figure 3)
(figure 3)
Warning
To avoid damage to the meter, or risk of personal
injury, do not attempt to measure higher than 600V
AC/DC, although readings may be obtained.
The DC Voltage ranges are:
400mV, 4V, 40V, 400V and 600V.
The AC Voltage ranges are:
4V, 40V, 400V and 600V.
To measure DC voltage, connect the Meter as follows:
Insert the red test lead into the Hz Duty% terminal and the black test lead
into the COM terminal.
1.
Red Black
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When DC/AC voltage measurement has been completed, disconnect the test
leads from the circuit under test, and remove them from the input terminals.
Set the rotary switch to . DC mesaurement mode and auto ranging is a default.
Press SELECT to switch to AC measurement mode or press to switch to
manual ranging measurement mode.
Connect the test leads across with the object being measured.
The measured value shows on the display.
2.
3.
VREL
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Note
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