TENMA 72-7228 User Manual

P/N: 110401100913

72-7228

Digital Clamp Multimeter

Model 72-7228

OPERATING MANUAL

Model 72-7228: OPERATING MANUAL

Table of Contents
Title Page

Overview
Inspection
Safety Information
Rules For Safe Operation
International Electrical Symbols
The Meter Structure
Functional Buttons
The Effectiveness of Functional Buttons
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

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5
6
7
10
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12
14
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18
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Model 72-7228: OPERATING MANUAL

Title Page

G. DC Current Measurement
H. AC Current Measurement
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

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42
43
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45
45

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Model 72-7228: OPERATING MANUAL

Title Page

I. AC Current
Maintenance
A. General Service
B. Replacing the Battery

47
49
49
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Model 72-7228: OPERATING MANUAL

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 Model 72-7228 (hereafter referred to as “the Meter”) features
3 5/6 digits and a 6666 count display. It uses large scale integrated circuit with double
integrated A/D converter as its core and has full range overload protection.

The Meter will measure AC/DC voltage, AC/DC current, frequency, duty cycle,
resistance, diodes, continuity and surge current.

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Model 72-7228: OPERATING MANUAL

Inspection

Open the package case and take out the Meter. Carefully check the following items
for missing or damaged parts:

Item Description Qty

1
2
3
4

In the event items are missing or damaged, contact your dealer immediately.

Operating manual
Test Lead
Carry case
9V Battery (NEDA1604A or 6LF22)

5

1 piece
1 pair
1 piece
1 piece

Model 72-7228: OPERATING MANUAL

Safety Information

This Meter complies with the standards IEC61010-1; IEC61010-2-032: 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 10.

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Model 72-7228: OPERATING MANUAL

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 that 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 testing leads from

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Model 72-7228: OPERATING MANUAL

the input terminals of the Meter and turn the Meter power off.
Ensure the rotary switch is in the correct position prior to measurement.
To prevent damage to the meter, range or mode changes should not be
made during measurement.
Do not perform measurements 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 damage to the meter, do not input higher than
600V between the Meter’s two input terminals.
When working with effective voltages over 70VDC or 33VAC 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.
To avoid electric shock, do not touch the bare wires, connectors, unused
input terminals or the circuit under testing during measurement.
Disconnect circuit power and discharge all high-voltage capacitors before
testing resistance, continuity and diode.

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Model 72-7228: OPERATING MANUAL

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.
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 only.
Turn the Meter off when it is not in use and remove the battery if the meter
is not to be used for a long time.
Check the battery often as it may leak after some time. If leaking appears,
replace the battery immediately. A leaking battery will damage the Meter.

9

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
Danger of High Voltage
Conforms to Standards of European Union

Model 72-7228: OPERATING MANUAL

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Model 72-7228: OPERATING MANUAL

The Meter Structure (see figure 1)

Hand Guards: to protect user’s hand

1.
from touching the dangerous area.
Trigger: press the lever to open the

2.
transformer jaws. When the pressure
on the lever is released, the jaws will
close.
Functional Buttons

3.
Input Terminals

4.
LCD Display

5.
Rotary Switch

6.
Transformer Jaw: designed to pick up

7.
the AC and DC current flowing through
the conductor. For proper current
transfer and accuracy, the conductor
should pass perpendicular to the plane
of the jaw.

Figure 1

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Model 72-7228: OPERATING MANUAL

Functional Buttons

The following table provides information about the operation of functional buttons.

Button Operation Performed

MAX/MIN

HOLD

Starts recording of maximum and minimum values.
Press to step the display through high (MAX) and low (MIN) readings
at any mode.
Press and hold for one second to exit MAX/MIN mode.

Press again to turn the display backlight off, otherwise it will
turn off automatically after 1 minute.

Press HOLD to enter the Hold mode. The Meter will beep.
Press HOLD again to exit the Hold mode to return to measurement
mode, the Meter will beep.
You may also turn the rotary switch or press SELECT button to
exit the Hold mode.

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Model 72-7228: OPERATING MANUAL

Button Operation Performed
HOLD

Press HOLD button for 2 seconds when turning on the Meter to
display full icon.

Hz

When the Meter is at %Hz, V and A

, press Hz to measure

frequency and duty cycle.

ZERO Press ZERO to zero the display before measuring DC current.

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Model 72-7228: OPERATING MANUAL

Functional Buttons

Not every functional buttons may be used on every rotary switch position. The
following table describes which buttons may be used on which rotary switch positions.

Rotary Switch
Positions

V

%Hz

66A

1000A

66A

1000A

oCo

F

Functional Buttons

SELECT MAX/MIN

N/A
N/A
N/A

14

HOLD

Hz

N/A

N/A
N/A

ZERO

N/A
N/A
N/A

N/A
N/A

N/AN/A