Unit TU13BA User manual

UT139A/B/C

ILIMI-T
UT139A/B/C OPERATING MANUAL 1
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Table of Contents
I. Overview-------------------------------------------------------------------------------------------------------------------------- 1
II. Access ry------------------------------------------------------------------------------------------------------------------------ 1
III. Safety Operati n Regulati n------------------------------------------------------------------------------------------------ 1
IV. Electric Symb l----------------------------------------------------------------------------------------------------------------2
V. C mprehensive Specificati n------------------------------------------------------------------------------------------------3
VI. Appearance Structure--------------------------------------------------------------------------------------------------------4
VII. LCD Display-------------------------------------------------------------------------------------------------------------------5
VIII. Kn bs and Keys f r Range Selecti n
---------------------------------------------------------------------------------- 7
IX. Measurement Instructi n----------------------------------------------------------------------------------------------------9
X. Technical Index--------------------------------------------------------------------------------------------------------------- 16
XI. Upkeep and Maintenance----------------------------------------------------------------------------------------------- 22

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UT139A/B/C OPERATING MANUAL
I. Overview
UT139A/B/C DMM is a small aut range, hand-held 3 1/2~3 5/6 bit true RMS multimeter featuring c mplete
functi n, n vel structure, high reliability and safety as well as large screen f r display . It can be used f r
measuring AC/DC v ltage and current, variable frequency v ltage (V.F.C), resistance, di de, circuit n- ff,
capacitance, frequency rati , NCV n n-c ntact AC v ltage sensing and s n, is an ideal p rtable maintenance
instrument f r users.
II. Accessory
Unpack and take ut the instrument, please check f ll wing attachments carefully f r c mpleteness r intactness.
In case f any sh rtage r damage, please c ntact with y ur supplier.
1. An perating instructi n manual
2. A test pen (CATIII 600V)
3. P int-type K( nickel chr mium ^nickel silic n) therm c uple (UT139C nly)
4. An pti nal current clamp (UT139C nly)
III. Safety Operation Regulation
UT139A/B/C is designed in c mpliance with standards such as IEC/EN61010-1, p lluti n grade II, verv ltage
(CATIII600V) and d uble insulati n standards. Please c mply with perati n instructi n specified in the Manual;
therwise the pr tecti n pr vided by the instrument may be affected.
1. It is f rbidden t use the pr duct with ut having rear cap in place, r therwise there will be electric sh cking.
2. Pri r t use, inspect the insulati n layer f test pen f r intactness, c nfirming n breakage and br ken line.
3. When LCD display sh ws the ic n “ ”, it is required t replace the battery in time t ensure the measurement
accuracy.
4. Range switch shall be set at the c rrect measurement p siti n.
UT 139A/B/C OPERATING MANUAL
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5. In case f electric sh ck and damage t the instrument, signals being measured shall n t exceed rated limit
value.
6. T prevent any damage t the instrument, it is f rbidden t change the gear f range switch in measurement.
7. After each measurement, disc nnect table pen and the circuit being measured; after the current measurement,
especially the measurement f large current, it is necessary t p wer ff bef re disc nnecting table pen
and the circuit being measured.
8. In case f electric sh ck, it is required t be cauti us when v ltage being measured higher than DC 60V
r AC 30Vrms.
9. D n t use the pr duct in high-temperature r high-humidity envir nment, particularly in the damp envir nment
in where the instrument perf rmance may be severely degraded
10. Refrain fr m changing the internal wiring in the clamp ammeter t guard against damage t the meter
and danger.
11. Clean the meter case with damp cl th and mild detergent rather than the abrasive material and s lvent.
IV. Electric Sy bol
aL w electricity f internal battery
•») Buzzing On- ff
-H- Di de
AC/DC
A
Warning
HHhBattery t be measured
_ L Gr unding
&Current clamp
mD uble Insulati n
C mply with Eur pean Uni n directiv

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H I H I ■ UT139A/B/C OPERATING MANUAL
V. Co prehensive Specification
1. Maximum v ltage between input terminal and gr unding: see instructi n ab ut each input terminal pr tecti n v ltage.
2. 10A terminal (CE) is equipped with:
F 10A H 600V fast-acting fuse (06x25) mm
3. mA/|jA terminal (CE) is equipped with:
UT139A-FF 0.2A H 600V fast-acting fuse (06x32) mm
UT139B-FF 0.5A H 600V fast-acting fuse (06x32) mm
UT139C-FF 0.6A H 600V fast-acting fuse (06x32) mm
4. Maximum display: (UT139A): 1999; (UT139B): 4000; (UT139C): 6000Refresh 2—3 times per sec nd, display
“OL” in case f verrange .
Capacitance and frequency ( nly applicable f r UT139B/C): 9999 c unt.
Duty rati ( nly applicable f r UT139B/C): 1—99.9%
Di de: ab ut 2.1V (UT139A) and 3.2V(UT139B/C), displaying “OL” in case f verrange.
Range: aut /manual
P larity: aut
W rking temperature: 0°C—40°C
Relative humidity: ^75% when 0°C—30°C, and ^50% when 30°C— 40°C
St rage temperature: -10°C—50°C
5. Electr magnetic c mpatibility:
In 1V/m radi frequency (RF) field: Overall accuracy=specified accuracy + 5% f range, and n specified
index f r RF ver 1V/m.
6. Operating ASL: 0—2000m
7. Internal battery: AA R6P 1.5V*2
8. L w electricity: LCD displays
9. C nt ur dimensi n: ab ut (175x80x48.5) mm
10. Weight: ab ut 350g (inclusive f battery)
11. Safety Standard: IEC/EN 61010-1: CATIII600V; P lluti n grade II
12. Accreditati n: CE
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UT 139A/B/C OPERATING MANUAL 1jHHU 1
VI. Appearance Structure (See Figure 1)
1. Case
2. LCD Display
3/4/7.: Selecti n butt ns
5. Range Switch
6. Measuring input terminal
Figure 1 4

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UT139A/B/C OPERATING MANUAL
VII. LCD Display (See Figure 2)
139B/C-LCD:
A MkQ Ham V>i AF V F % Q ®
SjZj O O jZj
d MAX-MINAuto Range NCV A
Symb l Instructi n
1Data h ld pr mpt
2 — Negative reading
3 AC/DC AC/DC measurement pr mpt
4 MAX-MIN Maximum/Minimum/Maximum-Minimum value measurement pr mpt
5• a Under-v ltage internal battery
6Aut Range Aut matic range pr mpt
139A-LCD:
A MkQ tyA
Q NCV Auto Range MAX-MIN
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UT 139A/B/C OPERATING MANUAL 1
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7-H Di de measurement pr mpt
8•») Circuit n- ff measurement pr mpt
9
A
Relative measurement pr mpt
10 Q /kQ /M Q Resistance units: Ohm, Kil hm and Meg hm
11 Hz/kHz/MHZ requency units: Hz, kHz, MHz
12 %Duty rati measurement unit
13 V/V V ltage units: mV, V
14 |jA / A /A Current units: |jA, mA, A
15 nF/MF/ F Capacitance units: nF, u F, mF
16 °C Centigrade temperature unit
17 °F Fahrenheit temperature unit
18 (EF)NCV N n-c ntact AC v ltage sensing
19 d> Aut p wer- ff pr mpt
20 £Current clamp

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UT139A/B/C OPERATING MANUAL
VIII. Knobs and Keys for Range selection
Range L cati n Functi n
AC r DC v ltage measurement
aResistance measurement
■H- Measurement f di de PN juncti n v ltage
•»« Measurement f circuit n- ff
Capacitance measurement
Hz Frequency measurement
%Duty rati masurement
t Temperature measurement
iu& mASs lOASi AC/DC current measurement
60AS* A AC/DC current clamp measurement
NCV N n-c ntact AC v ltage sensing
OFF Switch ff internal electric p wer
Button:
RANGE butt n: it can be used f r selecting aut /manual range. After pressing, it will switch ne gear f switch,
when reading the highest gear, jump t the l west gear range and in turn. When the time f pressing butt n is
^2s r switching a range, y u'll exit the manual range m de. (Only applicable f r V ^ /n /I^ )
MAX/MIN button:
it can be used t aut matically enter the manual range m de. In such case, aut shutd wn functi n is disabled
and maximum value is displayed, after an ther pressing n the butt n, the minimum value will be displayed and
values are displayed in turn (maximum value-minimum value). When the time f pressing butt n is ^2s r
switching a range, y u'll exit data rec rding m de ( nly applicable f r V^, Q, l^and °C/°F)
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REL button:
it can be used t aut matically enter the manual range m de. The current displayed value will be taken as
the reference value and then the difference between the measured value and reference value will be displayed,
after an ther press, y u'll exit the relative measurement m de. (Only applicable f r V^, Q, °C/T andHfr)
The backlight will be illuminated when the time f pressing butt n is ^2s, after ab ut 15s, the backlight will
be aut matically turned ff; the backlight will be turned ff if pressing the key ^2s when the backlight is
illuminated, (Only applicable f r UT139Afull range: REL/LIGHT butt n)
NCV/ V'V button (Only applicable for UT139A):
It can be used t switch NCV/mV'V. F r detailed inf rmati n, see the perati n instructi n f r n n-c ntact
AC v ltage sensing.
Hz/% button (only applicable for UT139B/C):
It can be used t select the m de Hz/%, nly applicable f r the selecti n f frequency, AC v ltage/ current
measurement m des.
SELECT button:
it can be used t select range ( nly applicable f r multi-range). Under AC m de, press the butt n ^2s, display
“UFC”, enter V.F.C measurement m de and measure the variable frequency v ltage. After an ther ^2s
pressing n the butt n, display “End” and exit the V.F.C measurement m de.
HOLD button: (Applicable f r full range)
It can be used t l ck and h ld the displayed value, in such case, LCD displays the pr mpt “E l”, after an ther
press, it is unl cked and enter the n rmal measurement m de.
The backlight will be illuminated when the time f pressing butt n is ^2s, after ab ut 15s, the backlight will
be aut matically turned ff; and the backlight will be turned ff if pressing the key ^2s when the backlight is
illuminated, (Only applicable f r UT139Afull range: HOLD /LIGHT butt n)

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UT139A/B/C OPERATING MANUAL
IX. Measure ent Instruction
Check the built-in AA 1.5Vx2 battery, display will sh w the symb l “GS” when lack f p wer, and then replace
battery in time. It is required t pay attenti n t the symb l “A ” beside the test pen s cket, which reminds
ne f the fact that in case f measurement safety, testing v ltage r current shall n t exceed the specified
value
1. AC and DC Voltage Measure ent (See Figure 3)
1) C nnect the instrument with the l ad in parallel f r measurement.
2) When the input impedance f the instrument is ab ut 10M Q,
the l ad may cause measurement err r in the circuit with high
impedance. In m st cases, the err r can be neglected (0.1%
r l wer) if the circuit impedance is under 10k
^ Notes:
• It is f rbidden t input v ltage higher than 600Vrms, despite
f the p ssibility f measuring higher v ltage, as it may damage r ^ rl
the instrument.
• It is required t av id the electric sh ck in measuring high
v ltage.
(U TI 39 A) (U T1 W B /C )
RANGE RANGE
MAX MIN MA X MIN
R£LA/LBHTl2S j R EL A
H i %
HOL H0l /ltCHT(2S)
5ELECT SELECT
VJ.C(ACV) v.rc (A Cv )
AC/O C
UT 139A/B/C OPERATING MANUAL
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2. Resistance Measure ent (See Figure 4a)
C nnect the instrument with the l ad in parallel f r measurement.
^ Notes:
*. The display will sh w “OL” when the measured resistance
pen-circuit r resistance value exceeds the maximum range
f the instrument.
*. Pri r t measuring nline resistance, it is necessary t switch
ff all p wers in the circuits t be measured, and release all
residual charges t ensure the measurement accuracy.
*. In measuring l w resistance, a measurement err r in resistance
f ab ut 0.1 Q —0.2 will be resulted by the test pen. In rder
t acquire accurate reading, it is required t sh rt circuit the
test pen, take REL relative measurement m de t ensure the
measurement accuracy.
*. Check the test pen f r any l sening r ther reas ns in case
there is a resistance value n less than 0.5Q when test pen
is sh rt circuited.
*. Several sec nds may be required f r the reading stability when
measuring high resistance, which is n rmal f r high resistance
measurement.
*. By using the resistance measurement functi n, it is all wed
t make self-checking f the built-in fuse, see (Figuer 4b).
*. N input higher than DC 60V r AC 30V is all wed.
(u ru w o j ^ ( u rjs B /c)
RAHCE
IIA X HIM MAX UIN
RClA/U GI T(2S) REL &
M U ) H0LD/LIGH1{2S)
SELECT SELECT
Figuer 4a
}
(UTlUtA) j . (UI13W/C )
RAMPE m t t
IUH UN MAX HH
BELA/L(CHT(aS)| BEL A
HO. I) |HOLO/JCH(25)
SELGC* | SELECT
Figuer 4b

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UT139A/B/C OPERATING MANUAL
3. Circuit on-off easure ent (See Figure 5)
If the resistance f tw terminals t be measured is bigger than
150^, there will be a circuit break and buzzer will make n
s und; if the resistance is ^10 Q, the circuit is deemed with
g d c nductivity and buzzer will c ntinu usly s und.
^ Notes
*. Pri r t measuring nline circuit n- ff, it is necessary t switch
ff all p wer supplies in the circuits t be measured and
release all residual charges t ensure the measurement
accuracy.
* T prevent pers nal injury, it is n t all wed t input the v ltage
higher than DC 60V r AC 30V.
4. Diode easure ent (Figure 6)
“ OL” will be displayed when the di de t be measured is an
pen circuit r p larity is reversely c nnected. F r Silic n PN
juncti n, the n rmal value is n rmally 500~800mV.
As. Notes
* Pri r t measuring nline di de, it is necessary t switch ff all
p wer supplies in the circuits t be measured and release all
residual charges t ensure the measurement accuracy.
* Test v ltage f r di de is ab ut:
2.1V(UT139A),
3.2V(UT139B/C).
* T prevent pers nal injury, it is n t all wed t input the v ltage
higher than DC 60V r AC 30V
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5. Capacitance easure ent
(Only applicable for UT139B/C)
(See Figure 7) The instrument, when with ut any input, will
display a fixed reading which is the internal fixed capacitance
value. When measuring small range gear capacitance, the
ab ve value shall be subtracted fr m the value t be measured
t ensure the accuracy. The relative measurement REL functi n
can be used t aut matically subtract the value t facilitate the
measurement.
^ Notes
* The display will sh w “OL” when the capacit r t be bec mes
sh rt-circuited r the capacitance value exceeds the maximum
range f the instrument.
* Generally, several sec nds will be taken t measure high-capacity
capacit r.
* T prevent damage t the instrument and pers nal injury, it
is required bef re testing t release all residual charges,
which is particularly imp rtant f r capacit r with high v ltage.
6. Frequency/Duty Ratio Measure ent
(Only applicable
(See Figure 8) At the frequency measurement gear, press the
butt n Hz/% t select frequency/duty rati measurement m de.
^ Notes
* T prevent pers nal injury, it is n t all wed t input the v ltage
higher than DC 60V r AC 30V

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UT139A/B/C OPERATING MANUAL
7. Te perature easure ent (Only applicable for UT139C)
(See Figure 9) Temperature sens r: It is nly applicable f r K
(Ni-Cr and Ni- Si) therm c uple. After startup, “OL” is displayed,
c mplete Celsius r Fahrenheit temperature measurement by
c nnecting the pr duct with K-type temperature sens r.
T=1.8°C+32
Notes
The p int type K (Ni-Cr and Ni- Si) therm c uple is nly applicable
f r the measurement f temperature under 230°C/446°F.
8. AC and DC current easure ent (See Figure 10)
C nnect the instrument with the l ad in serial f r measurement.
AC measurement value will be true RMS.
& Notes
13
Bef re c nnecting instrument in serial with the l p t be
measured, switch ff the p wer supply.
In measurement, it is required t use pr per input terminal
and functi n gear; if unable t estimate the current, the
measurement sh uld start with the high aea,r range.
Fuses are pr vided inside the 10A, rrwu linput jacks. It is
f rbidden t c nnect the table pen test pin in paralfel with any
circuit, especially the p wer supply terminal, which may cause
damage t the instrument and pers nal injury.
F r security purp ses, when measuring current higher than
5A, the time f each measurement sh uld be c ntr lled less
than 10s and an interval f at least 15min sh uld be maintained.
When measuring AC current nline, it is all wed t press the
butt n Hz/% t display nline AC frequency/ duty rati .
60AAC and DC current clamp measurement (See Figure 11).
C nnect as sh wn in the figure with the attached current clamp.
(Only applicable f r UT139C)
(MIMA) i QJTUH /C)
RMKE [ RAHCC
IUX UN WAX W
KLA /UC H T{2Sj BEL A
Hi x
M I D HCH0AICHJ{?S)
5UEC T * U C T
Figure 10
UT 139A/B/C OPERATING MANUAL
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9. NCV Non-contact AC voltage sensing (See Figure 12)
If need t detect whether there is a AC v ltage r electr magnetic field, all w
the fr nt end f the instrument be cl se t the bject t be sensed. The anal g
quantity f sensed AC v ltage is ab ut: “EF” is displayed when ^critical v ltage.
“ EF” is displayed when UT139A> critical v ltage, a five-level s und effect
(buzzing s und) is generated acc rding t the v ltage Vd t mark the
difference f sensed v ltage.
is displayed when UT139B/C>critical v ltage, “ ------ ” is designed
acc rding t the size f v ltage Vd and acc mpanied by different buzzing
s unds t mark the difference f sensed v ltage.
By pressing NCV/mV^( nly applicable f r UT 139A), display the anal g
quantity f sensed mVM make the difference f AC v ltage.
^ Notes
Test pen is n t required f r measurement when the range kn b switch is set
at “NCV”.
10. Battery voltage easure ent (only applicable for UT139A)
(See Figure 13) The range gear 1.5V is nly applicable f r the measurement
f battery ^2V, with l ad resistance f ab ut 51 & , while the range
gear 9V is nly applicable f r the measurement f battery ^ 1 5V, with
l ad resistance f ab ut 1 k Q
*. T prevent built-in fuse F1 inside the instrument fr m burning ut
due t ver-l ad, it is f rbidden t measure the battery r p wer
supply bey nd the rated range.
*. The measuring time f r battery v ltage sh uld be as sh rt as p ssible
since there will be built-in anal g l ad p wer c nsumpti n which
may sh rten the service life f battery.
Figure 11
Figure 12
Figure 13 14

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UT 139A/B/C OPERATING MANUAL
11. Other functions:
*. After 2s f full display f ll wing startup, enter the n rmal measurement m de. “ErrE” will be displayed in
case f any fault t the internal EEPROM.
*. Aut p wer- ff: the instrument will be “aut matically p wered ff” t save energy in case f n perati n
t the kn b switch within 15min. Under aut p wer- ff statuts, any press n the SELECT f UT139A r any
butt n f UT139B/C will “aut matically ar use” the instrument, r restart the instrument by turning the kn b
switch t OFF. Under p wer- ff status, press n SELECT and p wer n, the buzzer will make five s unds
t remind that the aut p wer- ff functi n has been cancelled. Restarting the instrument after p wer- ff will
rec ver the aut p wer- ff functi n.
*. Buzzer: A “Beep” s und (ab ut 0.25s) fr m buzzer means the functi n butt n is valid when pressing any
butt n r turning the functi n butt n. When measuring v ltage r current: AC and DC v ltage > ab ut 600V
mA gear AC/DC current >190mA(UT139A), 390mA(UT139B), 590mA(UT139C)When A gear AC/DC current
is >10A, buzzer will make c ntinu us s unds t remain the ver-range. In additi n, the buzzer make make
5 c ntinu us s unds ab ut 1 min pri r t aut p wer- ff and then make ne l ng s und pri r t p wer- ff.
When the aut p wer- ff functi n is cancelled, 5 s unds will be made by the buzzer every 15min.
*. L w-v ltage detecti n: it is used t detect the internal VDD. When the v ltage is l wer than 2.4V, the battery
under-v ltage symb l will be displayed, and the n rmal perati n is available; while when l wer than 2.2V,
n perati n is all wed and nly the symb l is displayed after startup.
* When the battery supply v ltage is reduced t 2.6V, the LCD backlight is weak r can n t start; measurement
functi ns can still be used n rmally.
UT 139A/B/C OPERATING MANUAL
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X. Technical Index
Accuracy: ± (a% reading +b w rd number), ne year f guarantee peri d.
Ambient temperature: 23°C +5°C (73.4T + 9T ) Relative humidity: <75%.
1. DC voltage easure ent
Range Res luti n Accuracy
UT139A UT139B UT139C
20.00mV* 40.00mV* 60.00mV* 10|jV± (0.5% +2)
200.0mV** 400.0mV** 600.0mV** 0.1 mV
2.000V 4.000V 6.000V 1mV
± (0.7% +3)
20.00V 40.00V 60.00V 10mV
200.0V 400.0V 600.0V 0.1V
600V 600V 600V 1V
10MQ. (There will be unstable digital display in case f */** range pen-circuit; after c nnecting with
the l ad, it can be c ntr lled £ ±1)
* Range: 20mV range f r UT 139A,
40mV range f r UT 139B,
60mV range f r UT 139C.
* Range: 200mV range f r UT 139A
400mV range f r UT 139B
600mV range f r UT 139C.
Maximum input v ltage: ±600V
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