Clas Ohlson UNI-T UT131B User manual

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UNI-T UT131B Multimeter
Multimeter UNI-T UT131B
UNI-T UT131B multimeter
Yleismittari UNI-T UT131B
Art.no.
41-1599 Ver. 20180920
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m

23
English
UNI-T UT131B Multimeter
Art.no: 41-1599
Please read theentire instruction manual before using theproduct and then
save it for future reference. We reserve theright for any errors in text or
images and any necessary changes made to technical data. In theevent of
technical problems or other queries, please contact our Customer Services
(see address details on theback).
Information about themeter
Themultimeter has been designed and tested in accordance with
therequirements for installation category II up to nominal voltages of
250V and acontamination level of2.
Categorisation
Meters are divided into different categories depending on theelectrical
environment in which they are to be used and how safe/protective they are
in theevent of avoltagesurge.
Themeter label should indicate which category it belongs to.
Thecategorisation also determines how safe theinstrument is with regards
to any overvoltage which could represent ahazard for theuser.
Thecategorisation is described briefly below:
In theevent of avoltage surge in theelectricity grid (atransient from
alightning strike, etc.), therisk will be greatest where themains supply
cable enters thebuilding, for example. Further inside thebuilding,
theresistance (impedance) in thecables will increase and connected
devices will reduce and dissipate theovervoltage. Themeter category will
therefore determine which electrical environment theinstrument is designed
to be usedin.

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English
Thecategories which meters are divided into are as follows:
• Category I:For measuring electronics and products that have inbuilt
protection against voltage surges.
• Category II: For measuring single-phase equipment which is fed via
thebuilding’s electrical power supply system. Bothplug-connected and
permanently installed.
• Category III: For measuring thebuilding’s electrical systems.
Permanently installed cables, sockets, fuse boxes and switchgear
cabinets. Three-phase distribution (allpower supply cables and three-
phase equipment, machinery and appliances).
• Category IV: Three-phase at primary level and all conductors for
outdoor use.
This multimeter belongs to installation category II and is intended for
measuring voltages of up to 250V in single-phase products. Themeter
must not be used for measuring three-phase products, three-phase
conductors or switchgear cabinets even if thenominal voltage does not
exceed 250V.
Contamination level
Themeter is designed for use in environments in which contaminants
which do not conduct electricity are present. Withtheexception that
temporary conductor contamination can occur due to condensation.
Examples of environments with contamination level 2 are home
environments in dry rooms, offices, test stations and laboratories. Inother
words, rooms which have anormal indoor climate.
Themeter must not be used or stored in rooms where it could be exposed
to electrically conductive contaminants in any form (solid, liquid or gas).
Themeter should for example not be exposed to relative humidities in
excess of 75% or used in unheated rooms and must not be used in
wetrooms or outdoors where it could getwet.
It is not intended for use with electrical equipment which is used in industry
or agriculture.

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English
Safety
• This product conforms to thefollowing CE standards: EN611010-1:2010,
EN61010-2-030:2010, EN61326:2013, and CAT II: 250 V, Pollution
Degree II.
• Theproduct is intended for indoor use only.
• Make sure that theproduct is used safely by following thesafety
instructions and operating directions written in this instruction manual.
• Theproduct must never be used if it is in any way damaged or malfunctioning.
• Make sure that your fingers are behind thefinger guards when using
thetest leads.
• Make sure that thepower is turned off before working on thepower
circuit. Even low voltages can be dangerous!
• Do not measure voltages higher than 250 V DC or 250 V AC RMS using
this product.
• To avoid shocks you need to be very CAREFUL when you work with
voltages higher than 60 V DC or 35 V AC RMS. Voltages higher than this
pose arisk of harmful electric shocks.
• Set theright measuring range using theselector before starting to
measure and do not change therange whilst taking ameasurement.
• Never use theproduct if thebattery cover is missing or thebattery
compartment is open.
• To avoid electric shocks and damage to themeter, do not exceed
theproduct’s overload limits.
• This product is protected by fuses, but they will not protect themeter
from all kinds of misuse.
• Theproduct must not be used in humid, explosive or flammable environments
or close to strong magnetic fields.
• Replace thebattery as soon as thebattery warning symbol appears on
thedisplay, alow battery can cause anincorrect reading and constitute
asafety hazard.
• Neither theproduct nor its accessories may be dismantled or modified
in any way.
• Remove thebattery from themeter if it is not to be used for anextended
period.
• Turn theproduct off after use.
• If theproduct is placed close to astrong magnetic field it might cause
incorrect readings which can be corrected by removing thecause of
theinterference.

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English
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
5
6
2
1
37
4
Buttons and functions
1. Display
2. [HOLD/SEL] Press this
key to hold areading, to
change between diode
mode and continuity mode
buzzer (yellow symbol).
3. : connection
for red test lead when
measuring DC current up
to 10A.
4. : connection for
theblack test lead (common).
5. [] Press to switch
thebacklight on/
off. Thelight goes off
automatically after 30 seconds
if not switched off.
6. Function selector switch
7. : connection
for red test lead when
measuring voltage,
measuring DC current
up to 0.2 A, measuring
resistance, testing diodes,
measuring continuity and
measuring temperature.
Display symbols
• TheHOLD function is engaged.
• Thebatteries need to be replaced 2×AAA/LR03, 1.5 V.
• This symbol appears when theresistor or diode is faulty or
thevoltage exceeds therange (overload). Thesymbol might also appear
when ameasurement is made with reversed polarity.

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English
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
Instructions for use
Warning:
• When measuring voltage always ensure that themultimeter is switched
to thecorrect measuring range and not set to thecurrent, resistance
or diode test range. Always ensure that you use thecorrect test lead
terminal for thetype of measurement to be made.
• Use extreme caution when measuring voltages over 60 V, especially
when theobject being measured has ahigh power output.
• Make sure that theobject to be measured is not energised (conducting
any current) before connecting test leads in series with it (such as when
measuring current).
• Make sure that thecircuit to be tested is not energised before performing
resistance measurements or diode tests.
• Always ensure that thecorrect function and range is selected. If in doubt
about thecorrect range, start with thehighest and work downwards.
• Be extremely cautious when using themultimeter on aninductive
component such as atransformer, relay coil and thelike. High voltage
may be induced at themeasuring points if anopen circuit occurs.
• Make sure that thetest leads are in good condition with no damage to
theinsulation.
• If you replace thefuse, make sure that it is thecorrect type and rating.
Voltage measurement
Check thebattery status by
turning thefunction selector
to anew range. Thebattery
symbol will appear if
thebattery is low.
1. Connect theblack test lead
to COM and thered lead to
VmAµA.
2. Set thefunction selector to
V (200/250V~) or
V (200 mV – 250V) and
thedesired voltage range.

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English
3. Connect thetest leads across thecircuit to be tested.
Read thedisplayed value.
Note: If thewrong polarity is connected when measuring direct current,
aminus sign (−) will be displayed in front of thevalue.
Battery measurement
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
1. Connect theblack test
lead to COM and thered
lead to VmAµA.
2. Set thefunction selector
to 12 V, 9Vor 1.5 V
depending on thetype
of battery you wish to
measure.
3. Thestatus of
themeasured battery is
described on thedisplay
as either Good, Low or
Bad:
Battery model 1.5 V 9 V 12 V
Load resistance 30 Ω 900 Ω 60 Ω
Good ≥ 1.31 V ≥ 7.8 V ≥ 10.5 V
Low 0.95–1.31 V 5.7–7.7 V 7.6–10.4 V
Bad ≤ 0.94 V ≤ 5.6 V ≤ 7.5 V

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DC current measurement
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
1. Connect theblack test
lead to COM and thered
lead to VmAµA (for
measuring 0–200mA) or
to 10A MAX (for measuring
200mA – 10 A).
2. Set thefunction selector
switch to A .
3. Connect thetest leads
in series with theload
and source of thecurrent
to be measured. Read
thedisplayed value.
Warning:
Do not connect thetest leads in parallel with thevoltage source when
measuring voltage!
If in doubt about thecorrect measuring range, start with thehighest and
work downwards.
When measuring high currents, themultimeter should only be connected
briefly (less than 10 seconds for currents greater than 10 A). This is to
prevent theshunt inside theinstrument from overheating
Theinterval between two readings must be greater than 15 minutes.

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English
Diode testing
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
1. Connect theblack test lead
to COM and thered lead
to VmAµA.
2. Set thefunction selector
switch to and press
[HOLD/SEL] to measure
thethreshold value (V) of
diodes.
3. Connect theblack test
lead to thecathode and
red test lead to theanode
of thediode to be
tested. Read theforward
voltage drop value from
thedisplay. If “ ” appears
on thedisplay, reverse
thepolarity of thediode
connections.If that doesn’t
help, thediode may be
faulty.
Warning:
Make sure that thecircuit to be tested is not energised before you begin
to test diodes. Be extremely cautious when using this instrument on
aninductive component such as atransformer, relay coil and thelike,
and make sure it has been discharged beforehand. High voltage may be
induced at themeasuring points when thecircuit is broken.
Note: Agood diode should have aforward voltage drop ranging from
0.5 to 0.8 V. However, thereverse voltage drop reading can vary alot
depending on theresistance of other paths of conductance between
thetips of thetest leads.

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English
Continuity test
UT131B
HOLD/SEL
FUSED
250V Max
10 sec Max
FUSED
200mA Max
CAT II 250V
OFF
20M
200k
20k
10 12V 9V
1.5V
2000
200
200
V
V
200m
2000m
200
20
250
250
200μ
200m
1. Connect theblack test lead
to COM and thered lead
to VmAµA. Set thefunction
selector switch to .
2. Connect theends of
thetest leads to theends of
thecables to be tested.
- No break in thecable:
Thebuzzer sounds
continuously if
theresistance is ≤ 10Ω.
- Abreak in thecable:
Thebuzzer does not
sound if theresistance
is >51Ω.
Warning:
Make sure that thecircuit to be tested is not energised before testing for continuity.
Be extremely cautious when using this instrument on aninductive
component such as atransformer, relay coil and thelike, and make sure
it has been discharged beforehand. High voltage may be induced at
themeasuring points if anopen circuit occurs.
To avoid shocks you need to be CAREFUL when you work with voltages
higher than 60 V DC or 30 V AC RMS. Voltages higher than this pose arisk
of harmful electric shocks.
Note: Theopen circuit voltage is around 2.1 V.