UNI-T UT51-55, UT51, UT52, UT53, UT54 Operating Manual

Contents

A Your Meters Feature
B Specifications
C Making Measurements

D Maintenance
E Accessories
F Using Holster

G Using Strap

Introduction

One kind of UNI-T brand new UT50 series
Multimeters is a 3 1/2 digit with steady function
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
can measure DC current, AC current, DC Voltage,
AC Voltage, Resistance, Capacitance, Diode,
Temperature, Frequency and Continuity, which is
an ideal tool for users.

Model UT51-55: OPERATING MANUAL

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Safety Rules

l Do not operate the Meter before the cabinet

has been closed and screwed safely as

terminal can carry voltage.

l Make sure before each measurement the

Meter is set to the suitable range.

l Before using the Meter, please inspect the

cabinet and test leads for damaged insulation

or exposed metal.

l Connect the red and black test lead to the

correct measuring input jack properly.

l Do not input values over the maximum

range of each measurement to avoid damages

of the Meter.

l The UNI-T UT50 series comply with

IEC 61010: in pollution degree 2,

overvoltage category (CAT I 1000V and

CAT II 600V) and double insulation.

Use the Meter only as specified in this

manual, otherwise the protection provided

by the Meter may be impaired.

l CAT I-For signal level, telecommunication,

electronic with small transient over voltage.

l CAT II -For local level, appliances, main

wall outlets, portable equipment.

l The meter is designed to withstand the

stated Max. voltages. If it’s not possible

to exclude without doubts that impulses,

transients, disturbance or for other reasons,

these voltages are exceeded a suitable

prescale (10:1) must be used.

l Do not turn the rotary function switch

during Voltage and Current measurement,

otherwise the Meter could be destroyed.

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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 T urn off the Meter once finished measuring,
fetch out the battery, when the meter will
not be used for long period.
l Do not operate the Meter under adverse
environmental condition especially humid
area.
l To avoid damages and dangerous, do not
change the circuit.
l Periodically wipe the case with a damp
cloth and mild detergent. Do not use
abrasives or solvents.

l International Electrical Symbols:

Low Battery Earth Ground
Safety Rules

Double Insulated

AC

Diode

Dangerous Voltages

DC

Buzzer

Fuse

l Make sure to use new fuses with proper
rating in stead of bad fuses .
l To avoid electric shock or damages, do
not apply more than 1000V between the
"COM" terminals and" "earth ground.
l Use caution when working with Voltages
above 60V (DC) or 30Vrms (AC). These
Voltages pose shock hazard.

l The Meter is suitable for indoor use only.

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A. Your Meters Feature

l 32 ranges.
l Liquid Crystal Display , digits height is 27mm.
l Overload display l.
l Maximum display 1999 (3 1/2 digit).
l Full range overload protection.
l Auto-Power Off (For UT53, UT54 and UT55

ONLY).
l Temperature:
Operating:0

o

C to 40oC (32

0

F to 104 0F).

Storing:-10

o

C to 50oC (14

0

F to 122 0F ).

l Altitude:
Operating: 2000m
Storing: 10000m.
l Relative Humidity:Max. relative humidity
80% for temperature up to 31

o

C decreasing

linearly to 50% relative humidity at 40

o

C.

l Low Battery display " " .
l Strap for easy carry.

l Tilt stand design, three observation angles,

is in favor of reading display.

l Dimension: 190mm x 88mm x 34mm.
l Weight: Meter only(excluding test leads)

about 270g .Meter + holster + tilt stand
about 550g.

l Battery T ype: 9V NEDA 1604 or 6F22 or 006P

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B. Specifications

Accuracy is specified for one year after calibration,

at operating temperatures 23

o

C +/- 5oC, with relative

humidity at < 75%.Accuracy specifications take

the form of:+/- (a% readings +digits )

B-1Direct Current Voltage (DC Voltage)

Input impedance: All ranges are 10MΩ .
Overload protection: 200mV is 250VDC or AC
RMS. All other ranges is 750Vrms or 1000Vp-p.

B-2 Alternating Current Voltage (AC Voltage)

Input impedance: All ranges are 10MΩ.
Frequency: 40Hz-400Hz .
Overload protection: 200mV is 250VDC or AC
RMS. All other ranges is 750Vrms or 1000Vp-p.
Display: Average Value (RMS of Sine Wave).

200mV

2V

20V

200V

1000V

100µV

1mV

10mV

100mV

1V

Range Resolution

(0.5% +1)

UT51 UT 52 UT53 UT54 UT55

Accuracy

(0.8% +2)

200mV

2V

20V
200V
750V

100µV

1mV

10mV

100mV

1V

Range Resolution

UT51 UT 52 UT53 UT54 UT55

Accuracy

(1.2% +3)

(0.8% +3)
(1.2% +3)

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B-3 Direct Current Current (DC Current)

Overload protection:

20µA

200µA

2mA
20mA

200mA

2A
10A
20A

0.01µA

0.1 µA
1 µA

10µA

100 µA

1mA

Range Resolution

UT51 UT 52 UT53 UT54 UT55

Accuracy

(2%+5)

(0.8%+1)

(1.5%+1 )

(0.8%+1)

10mA

(1.5%+1)

(2%+5)

(2%+5 )

For UT51:

2A, 250V fast acting fuse, φ5x20mm(below
2A range)

10A, 250V fast acting fuse,φ5x20mm(at 10A
range) .

For UT52/53/54/55:

315mA, 250V fast acting fuse, φ5x20mm (No
fuse at 20A range).
Max current input :
For UT51: 10A (The measurement time
for high current should be less than 10
seconds maximum, and the interval time
between two measurements should be greater
than 15 minutes.
For UT52/53/54/55: 20A (The measurement
time for high current should be less than 15
seconds maximum, and the interval time
between two measurements should be greater
than 15 minutes.

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