UNI-T UT50A, UT50B, UT50C Operating Manual

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Model UT50A/B/C: OPERATING MANUAL

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Table of Contents

Title

Overview
Unpacking Inspection
Safety Information
Rules For Safe Operation
International Electrical Symbols
The multimeter 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. The Model UT50C:

Frequency Measurement
G. The Model UT50B/UT50C:

Temperature Measurement

H. Capacitance Measurement
I. Measuring Diodes & Continuity

General Specifications

Testing for Continuity
Sleep Mode
Turning on the Auto Display Backlight

Accuracy Specifications

A. DC Voltage
B. AC Voltage
C. DC Current
D. AC Current

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I. Diodes and Continuity Test

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C. Replacing the Fuses

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Title

E. Resistance Test
F. The Model UT50C: Frequency
G. The Model UT50B/UT50C:

Temperature
H. Capacitance

Maintenance

A. General Service
B. Replacing the Battery

Overview

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

Digital Multimeters Model UT50A, UT50B and UT50C
(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, Frequency , Diodes and Continuity, but also
has Data Hold, Full Icon Display and Sleep Mode features.

The Meter adopted advanced “co-injection” technique in
order to provide sufficient insulation and anti-shaking.
In addition, the Automatic Display Backlight feature
enables user to work in a dim condition.

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Unpacking Inspection

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

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

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Item

1
2

3
4

Description

English Operating Manual
Test Lead
Test Clip

Point Contact Temperature Probe
(UT50B/UT50C only)

Qty

1 piece

1 pair
1 pair

1 piece

Safety Information

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

CA T. II: Local level, appliance, PORTABLE EQUIPMENT
etc., with smaller transient voltage overvoltages than
CAT. III
CA T. 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 on.
International electrical symbols used on the Meter and
in this Operating Manual are explained on page 8.

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Rules For Safe Operation (1)

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:

l 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.
l 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.
l Do not apply more than the rated voltage, as
marked on the Meter, between the terminals or
between any terminal and grounding.
l 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.
l 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.
l Use the proper terminals, function, and range
for your measurements.
l 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.

l When using the test leads, keep your fingers
behind the finger guards.

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Rules For Safe Operation (2)

l Disconnect circuit power and discharge all high­ voltage capacitors before testing resistance,
continuity, diodes, capacitance or current.
l Before measuring current, check the Meter’s
fuses and turn off power to the circuit before
connecting the Meter to the circuit.
l 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.
l Remove test leads, test clips and temperature
probe from the Meter and turn the Meter power
off before opening the Meter case.
l When servicing the Meter, use only the same
model number or identical electrical specifications
replacement parts.
l The internal circuit of the Meter shall not be
altered at will to avoid damage of the Meter and
any accident.
l 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.

l The Meter is suitable for indoor use.
l Turn the Meter power off when it is not in use

and take out the battery when not using for a
long time.
l 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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International Electrical Symbols

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

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The multimeter Structure (see figure 1)

9

( figure 1)

1 LCD Display
2 Data Hold Button.
3 Rotary Switch
4 Other Input Terminals
5 COM Input Terminal
6 20A Input Terminal

7 The Model UT50A:µAmA Input terminal
The Model UT50B/UT50C:mA Input terminal

8 Power

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Functional Buttons

Button Operation Performed

Turn the Meter on and off.
l Press down the POWER to turn
on the Meter.
l Press up the POWER to turn off
the Meter.

HOLD

(Blue Button)

l Press HOLD once to enter hold
mode.
l Press HOLD again to exit hold
mode.
l In Hold mode, is displayed and
the present value is shown.

POWER

(Yellow Button)

Below table indicated for information about the functional
button operations

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Display Symbols (see figure 2)

( figure 2)

No. Symbol Meaning

1

Dangerous Voltages.

2

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.

3

Indicator for AC voltage or
current.The displayed value is the
mean value.

4

Indicates negative reading.

5

Test of diode.

6

Data hold is active.

7

The continuity buzzer is on.

8

Centigrade temperature

o

C

o

F

9

Fahrenheit temperature

µA, mA, A

A: Amperes (amps). The unit of
current.
mA: Milliamp. 1 x 10-3 or 0.001
amperes.

µA: Microamp. 1x 10

-6

or 0.000001

amperes.

10

V: Volts. The unit of voltage.
mV: Millivolt. 1 x 10-3 or 0.001 volts.

mV, V

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