Prokit's Industries MT-3109 User Manual

MT-3109
AC/DC Digital Clamp Multimeter

User’s Manual

st

Edition, 2012

1

©2012 Copy Right by Prokit’s Industries Co., Ltd.

MT-3109 AC/DC Digital Clamp Multimeter

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 (hereafter
referred to as "the Meter") is 3 3/4 digits with steady operations,
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
The Meter can not only measure AC/DC Voltage, AC/DC
Current, Frequency, Duty Cycle, Resistance, Diodes, Continuity
but also it has Data Hold, Sleep Mode and Relative Mode
features.

Unpacking Inspection

Open the package case and take out the Meter. Check the
following items carefully to see any missing or damaged part:

Item Description Qty

1 User’s manual 1 piece
2 Test Lead 1 pair

3 Test Clip 1 pair

4 Carrying Bag 1 piece
In the event you find any missing or damage, please contact
your dealer immediately.

Safety Information

This Meter complies with the standards IEC61010: overvoltage
category (CAT.II 600V) and double insulation.
CAT. II: Local level, appliance, PORTABLE EQUIPMENT etc.,
with smaller transient over voltages than CAT.III
CAT. III: Distribution level, fixed installation, with smaller
transient over voltages than CAT. IV

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MT-3109 AC/DC Digital Clamp Multimeter

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

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
grounding 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 away from the input terminals of the Meter and turn the
Meter power off.

 The rotary switch should be placed in the right position and

no any changeover of range shall be made during
measurement is conducted to prevent damage of the Meter.

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MT-3109 AC/DC Digital Clamp Multimeter

 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 the Meter working at an effective voltage over 60V in

DC or 30V rms in AC, 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.

 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.
 Turn the Meter off when it is not in use and take out the

battery when not using for a long time.

 Constantly check the battery as it may leak when it has been

using for some time, Replace the battery as soon as leaking
appears. A leaking battery will damage the Meter.

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MT-3109 AC/DC Digital Clamp Multimeter

International Electrical Symbols

AC (Alternating Current)

DC (Direct Current)

AC or DC

Grounding

Double Insulated

Warning. Refer to the Operating Manual

Deficiency of Built-In Battery

Continuity Test

Diode

Capacitance Test

Fuse

Conforms to Standards of European Union

The Meter Structure (see figure 1)

1. Input

2. LCD Display

Terminals

figure.1

3. Functional Buttons

4. Rotary Switch

5. Trigger: press the lever to open the

transformer jaw

6. Hand Guards: to protect user's hand

from touching the dangerous area.

7. Transformer Jaw: designed to pick

up the AC and DC current flowing
through the conductor. It could transfer current to voltage.
The tested conductor must vertically go through the Jaw
center.

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MT-3109 AC/DC Digital Clamp Multimeter

Rotary Switch

Below table indicated for information of rotary switch positions.

Rotary Switch
Position

OFF

V

Ω

/

Hz / Duty %

40A & 400A

Function

Power is turned off

AC or DC voltage measurement

Resistance measurement

: Diode test : Continuity test

Frequency Measurement and Duty
Measurement

Capacitance test range from 40.OOnF to
1OO.OuF

AC and DC current measurement range

Functional Buttons

Below table for information of functional button operations.

Button

HOLD

Operation Performed

● Press HOLD to enter the Hold mode in any mode,
the Meter beeps.

● Press HOLD again to exit the Hold mode, the
Meter beeps.

and Ω range:

ELA

At

 Press select manual ranging measurement mode.

The Meter is default to auto ranging measurement
mode.

 When the Meter is at manual ranging measurement

mode, press to step down the range.

range:

At

 Press enter to the REL mode. It subtracts a stored

value from the present measurement value and
displays a result.

At Hz/Duty% range:

Press switch to between Hz measurement mode and
Duty % measurement mode.

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MT-3109 AC/DC Digital Clamp Multimeter

Button Operation Performed

Select

 Press SELECT button to select the alternate

functions marked in blue color on the Meter's
faceplate including Hz, Duty%,

, and 400 .

40

, ,

 After the Meter entering Sleep Mode, press and

hold SELECT to turn the Meter on, it will disable the
Sleep Mode feature.

The Effectiveness of Functional Buttons

Not every functional buttons can be used on every rotary switch
positions. Below table describe which functional buttons can be
used on which rotary switch positions

Rotary Switch Functional Buttons
Positions SELECT RELA HOLD

● ● ●

Ω N/A ● ●

/ ● N/A ●
Hz / Duty% N/A ● ●
40 ● ● ●
400 ● ● ●

N/A ● ●

Display Symbols (see figure 2)

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MT-3109 AC/DC Digital Clamp Multimeter

No. Symbol

1 AC

2 DC

3

4

5

6

7 %

8

9

10 Ω,KΩ,

MΩ

11 Hz

12 A

13

mV, V

14

15 TRMS

16 F,nF,uF,

17 OL

Meaning

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.

Test of diode

The continuity buzzer is on

Indicator for Duty.

Data hold is active

Indicator for REL mode

Ω: Ohm. The unit of resistance.
kΩ: Kilohm. 1x10
MΩ: Megohm. 1x106 or 1,000,000 ohms

3

or 1000 ohms

The unit of Frequency

Amperes (amps). The unit of current.

Volts. The unit of voltage.
mV: Millivolt. 1xl0

-3

or 0.001 volts

Indicates negative reading

Indicator for TRMS mode

Farad. The unit of capacitance.

The input value is too large for the selected
range

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MT-3109 AC/DC Digital Clamp Multimeter

Measurement Operation

A. DC/AC Voltage Measurement
(see figure 3)

Warning

To avoid harms to you or
damages to the Meter from
electric shock, do not attempt
to measure voltages 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:
(1) Insert the red test lead into the Hz Duty%

VΩ

terminal and the black test lead into the COM terminal.

(2) Set the rotary switch to

. DC measurement mode and

auto ranging is a default.

(3) Press SELECT to switch to AC measurement mode or

press REL

to switch to manual ranging measurement

mode.

(4) Connect the test leads across with the object being

measured. The measured value shows on the display.

Note
A. When DC/AC voltage

measurement has been completed,
disconnect the connection between
the testing leads and the circuit
under test and remove testing
leads from the input terminals.

B. Measuring Resistance (see figure

4)

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MT /DC Digital Clamp Multimeter -3109 AC

Warning

To avoid damages 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:
400Ω, 4kΩ, 40kΩ,400kΩ,4 MΩ and 40MΩ.
To measure resistance, connect the Meter as follows:

1. Insert the red test lead into the Hz Duty%

terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to Ω. Resistance measurement is
default to auto range mode, press RELA to switch to manual
ranging measurement mode.

3. Connect the test leads across with the object being
measured. The measured value shows on the display.

Note

 To obtain a more precise reading, you could remove the

objects being tested from the circuit when measuring,

 When resistance measurement has been completed,

disconnect the connection between the testing leads and the
circuit under test and remove testing leads from the input
terminals.

C. Testing Diodes (see figure 5)

Warning

To avoid damages 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 to check diodes,
transistors, and other semiconductor
devices. The diode test sends a
current through the semiconductor junction, then measure the

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MT-3109 AC/DC Digital Clamp Multimeter

voltage drop across the junction. A good silicon junction drops
between 0.5V and 0.8V.

To test the diode out of a circuit, connect the Meter as follows:

1. Insert the red test lead into the Hz Duty% -i))-H VQ terminal
and the black test lead into the COM terminal.

2. Set the rotary switch to
a default or presses SELECT to select

. Diode measurement mode is

measurement

mode.

3. For forward voltage drop readings on any semiconductor
component, place the red test lead on the component's
anode and place the black test lead on the component's
cathode.

Note

 To obtain a more precise reading, you could remove the

objects being tested from the circuit when measuring.

 When diode testing has been completed, disconnect the

connection between the testing leads and the circuit under
test and remove testing leads from the input terminals.

D. Testing for Continuity (see figure 6)

Warning

To avoid damages to the Meter or
to the devices under test,
disconnect circuit power and
discharge all the high-voltage
capacitors before measuring
continuity.

To test for continuity, connect the
Meter as follows:

1. Insert the red test lead into the Hz Duty%
terminal and the black test lead into the COM terminal.

2. Set the rotary switch to
to select

measurement mode. The buzzer sounds if

and press SELECT button

the resistance of a circuit under test is less than 50Ω

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