Tenma 72-7228 User manual

72-7228
P/N: 110401100913
Digital Clamp Multimeter

Model 72-7228
OPERATING MANUAL

Table of Contents
Title Page
Model 72-7228: OPERATING MANUAL
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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Title Page
Model 72-7228: OPERATING MANUAL
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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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Title Page
Model 72-7228: OPERATING MANUAL
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I. AC Current
Maintenance
A. General Service
B. Replacing the Battery
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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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Item Description Qty
1
2
3
4
Operating manual
Test Lead
Carry case
9V Battery (NEDA1604A or 6LF22)
1 piece
1 pair
1 piece
1 piece
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:
In the event items are missing or damaged, contact your dealer immediately.
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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. 6

Model 72-7228: OPERATING MANUAL
Rules For Safe Operation
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:
Warning
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.
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Model 72-7228: OPERATING MANUAL
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
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Model 72-7228: OPERATING MANUAL
Figure 1
The Meter Structure (see figure 1)
Hand Guards: to protect user’s hand
from touching the dangerous area.
Trigger: press the lever to open the
transformer jaws. When the pressure
on the lever is released, the jaws will
close.
Functional Buttons
Input Terminals
LCD Display
Rotary Switch
Transformer Jaw: designed to pick up
theAC and DC current flowing through
the conductor. For proper current
transfer and accuracy, the conductor
should pass perpendicular to the plane
of the jaw.
1.
2.
3.
4.
5.
6.
7.
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Model 72-7228: OPERATING MANUAL
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.
Functional Buttons
The following table provides information about the operation of functional buttons.
Button Operation Performed
MAX/MIN
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.
HOLD
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Model 72-7228: OPERATING MANUAL
Press HOLD button for 2 seconds when turning on the Meter to
display full icon.
Button Operation Performed
HOLD
When the Meter is at %Hz, VandA , press Hz to measure
frequency and duty cycle.
Hz
ZERO Press ZERO to zero the display before measuring DC current.
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SELECT MAX/MIN HOLD Hz ZERO
N/A
%Hz
66A
1000A
66A
1000A
N/A
N/A
N/A
N/A
N/AN/A
N/A
N/A
N/A
N/A
N/A
N/A
Rotary Switch
Positions
V
Functional Buttons
Model 72-7228: OPERATING MANUAL
Functional Buttons
oCoF
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.
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Model 72-7228: OPERATING MANUAL
Figure 2
Display Symbols (see figure 2)
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Number Symbol Meaning
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INRUSH
MIN
MAX
ZERO
Indicator for Surge current
Minimum reading displayed
Maximum reading displayed
Indicator for zeroing
Data hold is active
The Meter is in the auto range mode in which the
Meter automatically selects the range with the best
resolution.
True RMS indicator
Indicator for AC voltage or current
Indicates negative reading
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.
H
AUTO
RMS
AC
DC
Model 72-7228: OPERATING MANUAL
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Number Symbol Meaning
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Sleep mode is on
Diode test
The continuity buzzer is on
: Ohm. The unit of resistance.
k :Kilohm. 1x103 or 1000 ohms
M :Megohm. 1x106 or 1,000,000 ohms
Hz: Hertz. The unit of frequency.
KHz: Kilohertz. 1x103or 1000 hertz.
MHz: Meghertz. 1x106or1,000,000 hertz.
Volts. The unit of voltage.
mV: Millivolt. 1x10-3 or 0.001 volts
Amperes (amps). The unit of current.
The unit of temperature:
: Centigrade temperature
The unit of temperature:
: Fahrenheit temperature
Duty cycle measurement
,K ,M
Hz, kHz, MHz
mV, V
A
%
Model 72-7228: OPERATING MANUAL
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A. DC/AC Voltage Measurement (see figure 3)
To avoid personal injury or damage to the Meter from eletric shock, do not
attempt to measure voltages higher than 600V AC/DC, although readings may
be obtained.
Red Black
Red Black
Model 72-7228: OPERATING MANUAL
Measurement Operation
Figure 3
Warning
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