Unit UT50D User manual

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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. Inductance Measurement
G. Capacitance Measurement
H. Temperature Measurement
I. Measuring Diodes & Continuity
Sleep Mode
Turning on the Auto Display Backlight
General Specifications
Accuracy Specifications
A. DC Voltage
B. AC Voltage
C. DC Current
D. AC Current
E. Resistance Test
F. Inductance
G. Capacitance
H. Temperature
I. Diodes and Continuity Test
Table of Contents
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Maintenance
A. General Service
B. Replacing the Battery
C. Replacing the Fuses
Model UT50D: OPERATING MANUAL
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Digital Multimeters Model UT50D (hereafter referred to
as “the Meter”) is a 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,
Inductance, 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.
Warning
To avoid electric shock or personal injury, read the
“Safety Information” and “Rules for Safety Operation”
carefully before using the Meter.
Model UT50D: OPERATING MANUAL
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1 English Operating Manual 1 piece
2 Test Lead 1 pair
3 Test Clip 1 piece
4 Point Contact Temperature Probe
5 9V Battery (NEDA 1604, 6F22 or 009P)
(installed inside the Meter)
1 piece
1 piece
Item Description Qty
In the event you find any missing or damage, please
contact your dealer immediately.
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Model UT50D: OPERATING MANUAL

Safety Information
This Meter complies with the standards IEC61010: in
pollution degree 2, overvoltage category (CAT. II 1000V,
CAT. III 600V) and double insulation.
CAT. II: Local level, appliance, PORTABLE EQUIPMENT
etc., with smaller transient voltage 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 on.
International electrical symbols used on the Meter and
in this Operating Manual are explained on page 8.
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Model UT50D: OPERATING MANUAL

Rules For Safe Operation (1)
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.
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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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Model UT50D: OPERATING MANUAL

Rules For Safe Operation (2)
Disconnect circuit power and discharge all high
-voltage capacitors before testing resistance,
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, test clips 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. Aleaking battery will
damage the Meter.
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Model UT50D: OPERATING MANUAL

International Electrical Symbols
AC (Alternating Current).
DC (Direct Current).
Grounding.
Double Insulated.
Deficiency of Built-In Battery.
Warning. Refer to the Operating Manual.
Conforms to Standards of European Union.
Diode.
AC or DC.
Fuse.
Continuity Test.
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(figure 1)
The Meter Structure (see 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. mA Input terminal
8. Power
Model UT50D: OPERATING MANUAL

Button Operation Performed
Turn the Meter on and off.
lPress down the POWER to turn
on the Meter.
lPress up the POWER to turn off
the Meter.
HOLD
(Blue Button) lPress HOLD once to enter hold
mode.
lPress HOLD again to exit hold
mode.
lIn Hold mode, is displayed and
the present value is shown.
POWER
(Yellow Button)
Functional Buttons
Below table indicated for information about the functional
button operations
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(figure 2)
Display Symbols(1) (see figure 2)
No. Symbol Meaning
1Dangerous Voltages.
2The 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.
3Indicator for AC voltage or
current.The displayed value is the
mean value.
4Indicates negative reading.
5Test of diode.
6Data hold is active.
7The continuity buzzer is on.
8Centigrade temperature
oC
oF
9Fahrenheit temperature
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V: Volts. The unit of voltage.
mV: Millivolt. 1 x 10-3 or 0.001 volts.
mV, V
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No. Symbol Meaning
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mH,H
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H: Henry. The unit of Inductance.
mH: Millihenry. 1 x 10-3 or 0.001
henry.
Display Symbols(2) (see figure 2)
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Model UT50D: OPERATING MANUAL

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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(figure 3)
The DC Voltage ranges are: 200mV, 2V, 20V, 200V and
1000V. To measure DC voltage, connect the Meter as
follows:
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Model UT50D: OPERATING MANUAL
l 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.
l 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.
l In each range, the Meter has an input impedance of
approx. 10M . This loading effect can cause
measurement errors in high impedance circuits. If the
circuit impedance is less than or equal to 10k , the
error is negligible (0.1% or less).
l When DC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
1. Insert the red test lead into thei V nput 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.

The AC voltage measurement has 4 measurement
positions on the rotary switch: 2V, 20V, 200V and 750V
To measure AC Voltage, connect the Meter as follows:
l 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.
l 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.
l In each range, the Meter has an input impedance of
approx. 10M . This loading effect can cause
measurement errors in high impedance circuits. If the
circuit impedance is less than or equal to 10k , the
error is negligible (0.1% or less).
l When AC voltage measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
1. Insert the red test lead into the V 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).
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Model UT50D: OPERATING MANUAL

( figure 4)
The DC current measurement has 3 measurement
positions on the rotary switch: 2mA, 200mA and 20A.
To measure current, do the following:
1. Turn off power to the circuit. Discharge all high-
voltage capacitors.
2. Insert the red test lead into the mA or 20A terminal
and the black test lead into the COM terminal.
3. Set the rotary switch to an appropriate measurement
position in A range.
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Measurement Operation(5)
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.
l If the value of current to be measured is unknown,
use the maximum measurement position (20A) and
20A terminal, and reduce the range step by step until
a satisfactory reading is obtained.
l When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
( figure 4)
Model UT50D: OPERATING MANUAL

Measurement Operation(6)
The AC current measurement has 3 measurement positions
on the rotary switch: 20mA, 200mA and 20A.
To measure current, do the following:
1. Turn off power to the circuit. Discharge all high-voltage
capacitors.
2. Insert the red test lead into the mA or 20A terminal and
the black test lead into the COM 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.
l If the value of current to be measured is unknown, use
the maximum measurement position (20A) and 20A
terminal and reduce the range step by step until a
satisfactory reading is obtained.
l When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
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Measurement Operation(7)
( figure 5)
The resistance ranges are:200 ,2k ,200k ,2M ,and
20M .
To measure resistance, connect the Meter as follows:
1. Insert the red test lead into the V terminal and
the black test lead into the COM terminal.
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.
l The test leads can add 0.1 to0.3 of error when
measuring low resistance, that is the range of 200 .
To obtain precision readings in low-resistance, use
the following equation:
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Precision readings of resistance = Measurement
displayed reading minus the short circuit value of red
and black test lead.
l For high resistance (>1M ), it is normal taking several
seconds to obtain a stable reading.
l When there is no input, for example in open circuit
condition, the Meter displays “1”.
l When resistance measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
Measurement Operation(8)
( figure 6)
Inductance measurement has 4 measurement positions
on the rotary switch: 2mH, 20mH, 200mH and 20H.
To test for Inductance, connect the Meter as below:
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Model UT50D: OPERATING MANUAL