UNI-T UT39A, UT39C, UT39B Operating Manual

TABLE OF CONTENTS
TITLE PAGE

Overview
Unpacking Inspection
Safety Information
Rules For Safe Operation
International Electrical Symbols
The Meter Structure
Functional Buttons
Display Symbols
Measurement Operation
A. DC Voltage Measurement
B. AC Voltage Measurement
C. DC Current Measurement
D. AC Current Measurement
E. Measuring Resistance
F. Frequency Measurement (The Model UT39C only)
G. T emperature Measurement (The Model UT39C only)
H. Capacitance Measurement
I. Measuring Diodes & Continuity
J. Measuring Transistor
Sleep Mode
General Specifications
Accuracy Specifications
A. DC Voltage
B. AC Voltage
C. DC Current
D. AC Current
E. Resistance Test
F. Frequency (The Model UT39C only)
G. Temperature (The Model UT39C only)
H. Capacitance

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PAGE

I. Diodes and Continuity Test
J. Transistor Test
Maintenance
A. General Service
B. Replacing the Battery
C. Replacing the Fuses

Model UT39A/B/C: OPERATING MANUAL

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Overview

Warning
To avoid electric shock or personal injury, read the
“Safety Information” and “Rules for Safety Operation”
carefully before using the Meter.

Digital Multimeters Model UT39A, UT39B and UT39C
(hereafter referred to as “the Meter”) are 3 1/2 digits with
steady operations, fashionable structure and highly
reliable hand-held 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 not only can measure AC/DC
Voltage, AC/DC Current, Resistance, Capacitance,
Temperature, Transistor, Frequency, Diodes and
Continuity, but also has Data Hold and Sleep Mode
features.

The Meter comes with a holster which can provide
sufficient and anti-shaking.

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

English Operating Manual
Test Lead
Point Contact Temperature Probe
(UT39C only)
Holster
9V Battery (NEDA 1604 or 6F22 or 006P)

1
2
3

4
5

1 piece
1 pair
1 piece

1 piece
1 piece

In the event you find any missing or damage, please
contact your dealer immediately.

Model UT39A/B/C: OPERATING MANUAL

Safety Information

This Meter complies with the standards IEC61010: in
pollution degree 2, overvoltage category (CAT. I 1000V,
CAT. II 600V) and double insulation.

CAT. I: Signal level, special equipment or parts of
equipment, telecommunication, electronic, etc., with
smaller transient overvoltages than overvoltages CAT. II.

CA T. II: Local level, appliance, PORT ABLE EQUIPMENT
etc., with smaller transient voltage overvoltages than
CAT. III

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 on.

International electrical symbols used on the Meter and
in this Operating Manual are explained on page 7.

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Model UT39A/B/C: 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:

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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.
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.
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 high­voltage capacitors before testing resistance,

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Model UT39A/B/C: OPERATING MANUAL

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continuity, diodes, capacitance or current.
Before measuring current, check the Meter’s fuses
and turn off power to the circuit before connecting
the Meter to the circuit.
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.
Remove test leads and temperature probe from
the Meter and turn the Meter power off before
opening the Meter case.
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 power 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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Model UT39A/B/C: OPERATING MANUAL

Deficiency of Built-In Battery
AC (Alternating Current)
AC or DC
Double Insulated
Warning. Refer to the Operating Manual
Conforms to Standards of European Union
Grounding
DC (Direct Current)
Diode
Continuity Test
Fuse

International Electrical Symbols

The Meter Structure (see figure 1)

1. LCD Display

2. Data Hold Button

3. Transistor Jack

4. COM Input Terminal

5. Other Input Terminals

6. mA Input Terminal

7. 20A/10A Input Terminal

8. Capacitance Jack

9. Rotary Switch

10. Power

( figure 1)

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Model UT39A/B/C: OPERATING MANUAL

Button
POWER

(Y ellow Button)

HOLD

(Blue Button)

Operation Performed

Turn the Meter on and off.
Press down the POWER to turn on the Meter.
Press up the POWER to turn off the Meter.
Press HOLD once to enter hold mode.
Press HOLD again to exit hold mode.
In Hold mode, is displayed and the
present value is shown.

Functional Buttons

Below table indicated for information about the functional
button operations

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Display Symbols (see figure 2)

( figure 2)

Symbol

hFE

0

C

No.

1
2
3

4
5
6
7
8

Meaning

Data hold is active.
Indicates negative reading.
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.

Unit of Transistor
Centigrade temperature
Test of diode.
The continuity buzzer is on.
Dangerous Voltages.

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5

4

1

2
3

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Model UT39A/B/C: OPERATING MANUAL

9

Make sure the Sleep Mode is not on if you found there
is no display on the LCD after turning on the Meter.
Make sure the Low Battery Display is not on,
otherwise false readings may be provided.
Pay extra attention to the symbol which is located
besides the input terminals of the Meter before carrying
out measeurement.

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A. DC Voltage Measurement (see figure 3)

Warning
T o avoid harms to you or damages to the Meter from
electric shock, please do not attempt to measure
voltages higher than 1000V or 750V rms although
readings may be obtained.

Take extra attention when measuring high voltages
to avoid electric shock.

To measure DC voltage, connect the Meter as follows:

1. Insert the red test lead into the VΩ input terminal and
the black test lead into the COM input terminal.

2. Set the rotary switch to an appropriate measurement
position in V range.

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

( figure 3)

Black Red

Model UT39A/B/C: OPERATING MANUAL

Measurement Operation

Note

If the value of voltage to be measured is unknown,
use the maximum measurement position (1000V) and
reduce the range step by step until a satisfactory
reading is obtained.
The LCD displays “1” indicating the existing selected
range is overloaded, it is required to select a higher
range in order to obtain a correct reading.
In each range, the Meter has an input impedance of

approx. 10MΩ.This loading effect can cause
measurement errors in high impedance circuits. If the

circuit impedance is less than or equal to 10kΩ, the
error is negligible (0.1% or less).
When DC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

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B. AC Voltage Measurement (see figure 3 with dotted line)
Warning

T o avoid harms to you or damages to the Meter from
electric shock, please do not attempt to measure
voltages higher than 1000V or 750V rms although
readings may be obtained.

Take extra attention when measuring high voltages
to avoid electric shock.

To measure AC Voltage, connect the Meter as follows:

1. Insert the red test lead into the VΩ terminal and the
black test lead into the COM terminal.

2. Set the rotary switch to an appropriate measurement
position in V range.

3. Connect the test leads across with the object being
measured.
The measured value shows on the display, which is
effective value of sine wave (mean value response).

Model UT39A/B/C: OPERATING MANUAL

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Note

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If the value of voltage to be measured is unknown,
use the maximum measurement position (750V) and
reduce the range step by step until a satisfactory
reading is obtained.
The LCD displays “1” indicating the existing selected
range is overloaded, it is required to select a higher
range in order to obtain a correct reading.
In each range, the Meter has an input impedance of

approx. 10MΩ. This loading effect can cause
measurement errors in high impedance circuits. If the

circuit impedance is less than or equal to 10kΩ, the
error is negligible (0.1% or less).
When AC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

C. DC Current Measurement (see figure 4)

Warning
Never attempt an in-circuit current measurement
where the open circuit voltage between terminals
and ground is greater than 60V DC or 30V rms.

If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be
hurt. Disconnect power supply before making
measurement. Use proper terminals, function, and
range for the measurement. When the testing leads
are connected to the current terminals, do not parallel
them across any circuit.

( figure 4)

Black Red

Model UT39A/B/C: OPERATING MANUAL

4. Break the current path to be tested. Connect the red
test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.

5. Turn on power to the circuit.
The measured value shows on the display.

To measure current, do the following:

1. Turn of f power to the circuit. Discharge all high-voltage
capacitors.

2. Insert the red test lead into the mA or 20A or 10A

terminal and the black test lead into the COM terminal.
When measuring current at 200mA below, insert the
red test lead into mA terminal while measuring current
200mA or above, insert the red test lead into 10A or
20A terminal

3. Set the rotary switch to an appropriate measurement
position in A range.

Note

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If the value of current to be measured is unknown, use
the maximum measurement position (20A) and 20A
terminal or (10A) and 10A terminal, and reduce the
range step by step until a satisfactory reading is
obtained.
Replace appropriate rating fuse when the fuse is burnt.
Fuse specification: 0.315A. 250V fast type fuse,

φ 5 x 20mm
UT39A/UT39B - At 10A Range: For continuous
measurement 10 seconds and interval not less than
15 minutes.
UT39C – At 20A Range: For continuous measurement
10 seconds and interval not less than 15 minutes
When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

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Model UT39A/B/C: OPERATING MANUAL

D. AC Current Measurement (see figure 4 with dotted line)

Warning
Never attempt an in-circuit current measurement
where the voltage between terminals and ground is
greater than 60V or 30V rms

If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be
hurt. Disconnect power supply before making
measurement. Use proper terminals, function, and
range for the measurement. When the testing leads
are connected to the current terminals, do not parallel
them across any circuit.

To measure current, do the following:

1. Turn of f power to the circuit. Discharge all high-voltage
capacitors.

2. Insert the red test lead into the mA or 20A terminal

or 10A terminal and the black test lead into the COM
terminal. When measuring current at 200mA below,
insert the red test lead into mA terminal while
measuring current 200mA or above, insert the red
test lead into 10A or 20A terminal

3. Set the rotary switch to an appropriate measurement

position in A range.

4. Break the current path to be tested. Connect the red

test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.

5. Turn on power to the circuit.

The measured value shows on the display.

Note

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If the value of current to be measured is unknown, use
the maximum measurement position (20A) and 20A
terminal or (10A) and 10A terminal, and reduce the
range step by step until a satisfactory reading is
obtained.
Replace appropriate rating fuse when the fuse is burnt.
Fuse specification: 0.315A. 250V fast type fuse,

φ5 x 20mm
UT39A/UT39B - At 10A Range: For continuous
measurement 10 seconds and interval not less than
15 minutes.

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Model UT39A/B/C: OPERATING MANUAL

E. Measuring Resistance (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 measuring
resistance.

To measure resistance, connect the Meter as follows:

1. Insert the red test lead into the VΩ terminal and the
black test lead into the COM terminal.

2. Set the rotary switch to an appropriate measurement
position in Ω range.

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

Note

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The test leads can add 0.1Ω to 0.3Ω of error to the
resistance measurement. To obtain precision readings

in low-resistance, that is the range of 200Ω, short­circuit the red and black test leads beforehand and
record the reading obtained (called this reading as X).
Then use the equation:
measured resistance value (Y) – (X) = precision
readings of resistance.

For high resistance (>1MΩ), it is normal taking several
seconds to obtain a stable reading.

UT39C – At 20A Range: For continuous measurement
10 seconds and interval not less than 15 minutes
When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

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( figure 5)

Black Red

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Model UT39A/B/C: OPERATING MANUAL

F. The Model UT39C: Frequency Measurement

(see figure 6)

Warning
To avoid harm to you or damages to the Meter, do
not attempt to measure voltages higher than 60V in
DC or 30V rms in AC although readings may be
obtained.
When the frequency signal to be tested is higher
than 30V rms, the Meter cannot guarantee accuracy
of the measurement.

When there is no input, for example in open circuit
condition, the Meter displays “1”.
When resistance measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

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(figure 6)

To measure frequency, connect the Meter as follows:

1. Insert the red test lead into the VΩ terminal and the
black test lead into the COM terminal.

2. Set the rotary switch to an appropriate measurement
position in kHz range.

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

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When Hz measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.

Black Red

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Model UT39A/B/C: OPERATING MANUAL

G. The Model UT39C: T emperature Measurement

(see figure 7)

Warning
To avoid harm to you or damages to the Meter, do
not attempt to measure voltages higher than 60V in
DC or 30V rms in AC although readings may be
obtained.

(see figure 7)

To measure temperature, connect the Meter as follows:

1. Insert the red temperature into the VΩ terminal and
the black temperature probe into the COM terminal.

2. Set the rotary switch to 0C.

3. Place the temperature probe to the object being
measured.
The measured value shows on the display.

Note

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The Meter displays “1” when there is no temperature
probe connection.
The included temperature probe can only be measured
up to 2500C. For any mesaurement higher than that,
the rod type temperature probe must be used instead.
When temperature measeuremnet has been completed,
disconnect the connection between the testing leads
and te circuit under test.

Black Red

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H. Capacitance Measurement (see figure 8)

( figure 8)

Warning
To avoid damage to the Meter or to the equipment
under test, disconnect the tested circuit power when
measuring on line capacitors and discharge all high­voltage capacitors before measuring capacitance.
Use the DC voltage function to confirm that the
capacitor is discharged.

Never attempt to input over 60V in DC or 3V rms in
AC to avoid personal dangerous.

To measure capacitance, connect the Meter as follows:

1. Insert the capacitor to be tested into the capacitance
jack.

2. Set the rotary switch to an appropriate measurement
position in range.

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

Note

For testing the capacitor with polarity , connect the red
test lead to anode & black test lead to cathode
When the tested capacitor is shorted or the value is
overloaded, the LCD display “1”.
To minimize the measurement error caused by the
distributed capacitor, the connection should be as short
as possible.
It is normal to take a while for zeroing when changing
over the measurement range. This process will not
affect the accuracy of the final readings obtained.

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Model UT39A/B/C: OPERATING MANUAL

I. Measuring Diodes & Continuity
Warning

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

Never attempt to input over 60V in DC or 3V rms in
AC to avoid personal dangerous.

Testing Diodes
Use the diode test to check diodes, transistors, and other

semiconductor devices. The diode test sends a current
through the semiconductor junction, and then measures
the voltage drop across the junction. A good silicon
junction drops between 0.5V and 0.8V.

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

1. Insert the red test lead into the VΩ terminal and the
black test lead into the COM terminal.

2. Set the rotary switch to

.

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.
The LCD displays the nearest value of diode forward
voltage drop.

Note

In a circuit, a good diode should still produce a forward
voltage drop reading of 0.5V to 0.8V; however; the
reverse voltage drop reading can vary depending on
the resistance of other pathways between the probe
tips.
Connect the test leads to the proper terminals as said
above to avoid error display. The LCD displays “1”
indicating open-circuit for wrong connection. The unit
of diode is Volt (V), displaying the positive-connection
voltage-drop value.
When diode testing has been completed, disconnect
the connection between the testing leads and the
circuit under test.

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Model UT39A/B/C: OPERATING MANUAL

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Testing for Continuity
To test for continuity, connect the Meter as below:

1. Insert the red test lead into VΩ terminal and the black
test lead into the COM terminal.

2. Set the rotary switch to .

1. Connect the test leads across with the object being
measured.

4. The buzzer sounds continuously if the resistance of
a circuit under test is

10Ω, it indicates the circuit is
in good connection.
The buzzer does not sound if the resistance of a circuit

under test is>70Ω, it indicates broken circuit.
The buzzer may or may not sound if the resistance of

a circuit under test is between 10Ω to 70Ω.
The LCD displays the resistance value of a circuit
under test.

Note

The LCD displays “1” indicating the circuit being tested
is open.
When continuity testing has been completed,
disconnect the connection between the testing leads
and the circuit under test.

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J. Measuring Transistor (see figure 9)

( figure 9)

To measure transistor, connect the Meter as follows:

1. Set the rotary switch to hFE.

2. Insert the NPN or PNP type transistor to be tested
into the transistor jack

3. The measured nearest transistor value shows on the
display

Model UT39A/B/C: OPERATING MANUAL

Note

When transistor measeurement has been completed,
remove the transistor from the transistor jack.

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Sleep Mode

To preserve battery life, the Meter automatically turns
off if you do not turn the rotary switch or press any button
for around 15 minutes. At that time, the Meter consumes
around 10µA current.
The Meter can be activated by pressing the POWER two
times.

General Specifications

Maximum voltage between any Terminals and
Grounding: 1000V.
Fused Protection for mA Input Terminal: 0.315A,
250V fast type, φ 5 x 20mm.
Fused Protection for 10A or 20A Input Terminal:
Un-fused.
Range: Manual ranging.
Maximum Display: 1999.
Mesaurement Speed: Updates 2~3 times/second.
Temperature:
Operating: 00C~400C (320F~1040F);
Storage: -100C~500C( 140F~1220F).
Relative Humidity: 75% @ 00C~300C; 50% @
310C~400C
Altitude: Operating: 2000m; Storage: 10000m.
Battery Type: 9V NEDA1604 or 6F22 or 006P.
Battery Deficiency: Display “ ”.
Data Holding: Display “ ”
Negative reading: Display “ ”
Overloading: Display “1”.
Dimensions (HxWxL): 172x83x38mm.
Weight: Approx.310g (battery included).
Safety/Compliances: IEC61010 CAT I 1000V, CATII
600V overvoltage and double insulation standard.
Certificate:

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Model UT39A/B/C: OPERATING MANUAL

Accuracy Specifications

Accuracy: (a% reading + b digits), guarantee for 1 year.
Operating temperature: 230C 50C.
Relative humidity: <75%.
Temperature coefficient: 0.1 x (specified accuracy) / 10C

A. DC Voltage

Range Resolution

(0.5%+1)

Overload

Protection

250V DC

or AC rms.

1000V DC

or 750V AC.

Remark:

Input impedance: 10MΩ.

Accuracy

UT39A UT39B UT39C

200mV

2V

20V

200V

1000V

100µV

1mV

10mV

100mV

1V

(0.8%+2)

B. AC Voltage

Range Resolution

(0.8%+3)

Overload

Protection

1000V DC

or 750V AC

Remark:

Accuracy

UT39A UT39B UT39C

2V

20V
200V
750V

1mV

10mV

100mV

1V

(1.2%+3)

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Input impedance: 10MΩ.
Frequency response: 40Hz~400Hz.
Display effective value of sine wave (mean value
response).

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Model UT39A/B/C: OPERATING MANUAL

C. DC Current

Range Resolution

(2%+5)

Overload

Protection

0.315A. 250V

fast type fuse,

φ 5 x 20mm

Un-Fused

Accuracy

UT39A UT39B UT39C

20µA

200µA

2mA

20mA
200mA

10A/20A

0.01µA

0.1µA
1µA

10µA

100µA

10mA

(0.8%+3)

(0.8%+1)

(0.8%+1)

(1.5%+1)
(2%+5)

Remark:

UT39A/UT39B - At 10A Range: For continuous
measurement 10 seconds and interval not less than
15 minutes.
UT39C – At 20A Range: For continuous measurement

10 seconds and interval not less than 15 minutes

Measurement voltage drop: Full range at 200mV.

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D. AC Current

Range Resolution

(1%+3)

Overload

Protection

0.315A. 250V
fast type fuse,

φ 5 x 20mm

Un-Fused

Accuracy

UT39A UT39B UT39C

200µA

2mA

20mA

200mA

10A/20A

0.1µA

1µA

10µA

100µA

10mA

(3%+5)

Remark:

UT39A/UT39B - At 10A Range: For continuous
measurement 10 seconds and interval not less than
15 minutes.
UT39C – At 20A Range: For continuous measurement

10 seconds and interval not less than 15 minutes
Measurement voltage drop: Full range at 200mV.
Frequency reaponse: 40Hz~400Hz
Display effective value of sine wave (mean value
response).

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(1%+3)

(1%+3)

(1.8%+3)

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Model UT39A/B/C: OPERATING MANUAL

E. Resistance Test

Range Resolution

(0.8%+3)

Overload

Protection

250V DC

or AC rms

Accuracy

UT39A UT39B UT39C

200Ω

2kΩ

20kΩ

200kΩ

2MΩ

20MΩ

200MΩ

0.1Ω
1Ω

10Ω

100Ω

1kΩ

10kΩ

100kΩ

Remark:

Open circuit voltage:

At 200MΩ range: approx. 3V

Other ranges: 700mV
At 200MΩ range, test lead is in short circuit, and it is
normal to display 10 digits. During measurement,
subtract the 10 digits from the reading.

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(0.8%+1)

(0.8%+1)

(0.8%+1)

(1%+2)

[5%(reading-10)+10]

F. The Model UT39C: Frequency

Range Resolution

(2%+5)

Overload Protection

250V AC

Accuracy

2kHz

20kHz

1Hz

10Hz

(1.5%+5)

Remark:

Input Sensitivity: 200mV.
When the input voltage is 30V rms, no guaranteed
accuracy.

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G. The Model UT39C: Temperature

Range Resolution

(4%+4)

Overload Protection

250V AC

Accuracy

-400C~00C

10C~4000C

4010C~10000C

(2%+8)

(3%+10)

10C

23

Model UT39A/B/C: OPERATING MANUAL

H. Capacitance

Range Resolution

(4%+3)

Overload

Protection

250V AC

Accuracy

UT39A UT39B UT39C

1pF

0.1nF
1nF

10nF

(4%+3)

(4%+3)

Remark:

Testing signal: approx. 400Hz, 40mV rms.

l

I. Diodes and Continuity Test

Function

Diode

Continuity

Buzzer

RangeResolution

1mV

1

Input

Protection

250V DC

or AC

Remark

Open circuit voltage

approx.2.8V

Approx. <70

buzzer

beeps continuously

J. Transistor Test

Range

hFE

Remarks

Can measure NPN or PNP

transistor. Display range:

0-1000

Testing Conditions

Vce 2.8V

I bo

10µA

24

25

Maintenance

This section provides basic maintenance information
including battery and fuse replacement instruction.

Warning
Do not attempt to repair or service your Meter unless
you are qualified to do so and have the relevant
calibration, performance test, and service information.
To avoid electrical shock or damage to the Meter,
do not get water inside the case.

A. General Service

Periodically wipe the case with damp cloth and mild
detergent. Do not use chemical solvent.
To clean the terminals with cotton bar with detergent,
as dirt or moisture in the terminals can affect readings.
Press the Meter power off when it is not in use and
take out the battery when not using for a long time.
Do not store the Meter in place of humidity, high
temperature, explosive, inflammable and strong
magnetic field

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l
l
l

B. Replacing the Battery (see figure 10)

( figure 10)

Warning
T o avoid false readings, which could lead to possible
electric shock or personal injury , replace the battery
as soon as the battery indicator appears.

Model UT39A/B/C: OPERATING MANUAL

To replace battery:

1. Disconnect the connection between the testing leads
and the circuit under test, and remove the testing
leads away from the input terminals of the Meter.

2. Press the Meter power off

3. Remove the screw from the battery compartment,
and then take out the battery door from the battery
compartment.

4. Remove the battery from the battery compartment.

5. Replace the battery with a new 9V battery (NEDA
1604 or 6F22 or 006P).

6. Rejoin the battery door and the battery compartment,
and install the screw

C. Replacing the Fuses (see figure 11)

( figure 11)

SCREW

Warning
To avoid electrical shock or arc blast, or personal
injury or damage to the Meter, use specified fuses
ONLY in accordance with the following procedure.

To replace the Meter’s fuse:

1. Disconnect the connection between the testing leads
and the circuit under test, and remove the testing
leads away from the input terminals of the Meter.

2. Press the Meter power off.

3. Remove the holster from the Meter.

4. Remove the screw from the battery compartment,
and then take out the battery door.

5. Remove the screw inside the battery compartment
and also the other two screws from the case bottom,
and then separate the case bottom from the case top.

Model UT39A/B/C: OPERATING MANUAL

26

27

6. Remove the fuse by gently prying one end loose, and
then take out the fuse from its bracket.

7. Install ONL Y replacement fuses with the identical type
and specification as follows and make sure the fuse
is fixed firmly in the bracket.

0.315A. 250V fast type fuse, φ 5 x 20mm.

8. Rejoin the case bottom and the case top, and install
the screw.

9. Rejoin the battery door from the battery compartment,
and install the screw

10. Rejoin the holster and the Meter.
Replacement of fuses is seldom required. Burning of a

fuse always results from the improper operation.

** END **

This operating manual is subject to change without notice.

Model UT39A/B/C: OPERATING MANUAL

Copyright 2004 Uni-Trend Group Limited.

All rights reserved.
Manufacturer:

Uni-Trend Technology (Dongguan) Limited
Dong Fang Da Dao
Bei Shan Dong Fang Industrial Development District
Hu Men Town, Dongguan City
Guang Dong Province
China
Postal Code: 523 925

Headquarters:
Uni-Trend Group Limited
Rm901, 9/F, Nanyang Plaza
57 Hung To Road
Kwun Tong
Kowloon, Hong Kong
Tel: [phone]
Fax: [phone]
Email: [e-mail]
http://www.uni-trend.com

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Model UT39A/B/C: OPERATING MANUAL