UT55 Digital Multimeter
Product Information
The Model UT51-55 is a multi-purpose meter designed for various
electrical measurements. It complies with safety standards,
including IEC 61010, and offers protection against overvoltage. The
meter has a maximum voltage capacity and can withstand certain
levels of impulses, transients, and disturbances. It features a
rotary function switch for easy selection of measurement types and
ranges. The meter has a liquid crystal display (LCD) with a digit
height of 27mm for clear readings. It also has overload display and
full range overload protection. The meter is equipped with an
auto-power off function for energy conservation (applicable to
UT53, UT54, and UT55 models only). Additionally, the meter has a
low battery indicator and temperature measurement capability.
Product Usage Instructions
- Ensure that the meter is used in accordance with the
instructions provided in the manual to maintain its protection
capabilities. - Prior to use, inspect the cabinet and test leads for any signs
of damaged insulation or exposed metal. - Connect the red and black test leads to the correct measuring
input jacks. - Set the meter to the suitable range before each
measurement. - Do not input values that exceed the maximum range of each
measurement to prevent damage to the meter. - Avoid turning the rotary function switch during voltage and
current measurements to avoid potential damage to the meter. - Use caution when working with voltages above 60V (DC) or 30Vrms
(AC) as they pose a shock hazard. - Replace the battery as soon as the low battery indicator
appears to prevent false readings and potential electric
shock. - When finished measuring, turn off the meter and remove the
battery if it will not be used for an extended period. - Do not operate the meter under adverse environmental
conditions, especially in humid areas. - Periodically clean the meter’s case with a damp cloth and mild
detergent. Avoid using abrasives or solvents. - The meter is designed for indoor use only.
Note: Please refer to the manual for additional safety rules and
information on international electrical symbols.
Model UT51-55: 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.
1
Model UT51-55: OPERATING MANUAL
Safety Rules
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 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 Do not turn the rotary function switch during Voltage and Current measurement, otherwise the Meter could be destroyed.
2
Model UT51-55: OPERATING MANUAL
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 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 Turn 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 The Meter is suitable for indoor use only. l International Electrical Symbols:
Low Battery
Earth Ground
Safety Rules
Double Insulated
AC
Diode
DC
Buzzer
Fuse
Dangerous Voltages
3
Model UT51-55: OPERATING MANUAL
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:0oC to 40oC (32 0F to 104 0F). Storing:-10oC to 50oC (14 0F to 122 0F ). l Altitude: Operating: 2000m Storing: 10000m. l Relative Humidity:Max. relative humidity 80% for temperature up to 31oC decreasing linearly to 50% relative humidity at 40oC. l Low Battery display ” ” . l Battery Type: 9V NEDA 1604 or 6F22 or 006P 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.
4
Model UT51-55: OPERATING MANUAL
B. Specifications
Accuracy is specified for one year after calibration, at operating temperatures 23oC +/- 5oC, with relative humidity at < 75%.Accuracy specifications take the form of:+/- (a% readings +digits )
B-1Direct Current Voltage (DC Voltage)
Range
200mV 2V 20V
200V 1000V
Resolution
Accuracy UT51 UT 52 UT53 UT54
UT55
100µV
1mV 10mV
(0.5% +1)
100mV
1V
(0.8% +2)
Input impedance: All ranges are 10M . Overload protection: 200mV is 250VDC or AC RMS. All other ranges is 750Vrms or 1000Vp-p.
B-2 Alternating Current Voltage (AC Voltage)
Range
200mV 2V 20V
200V 750V
Resolution
Accuracy UT51 UT 52 UT53 UT54
UT55
100µV
(1.2% +3)
1mV
10mV
(0.8% +3)
100mV
1V
(1.2% +3)
Input impedance: All ranges are 10M. 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).
5
Model UT51-55: OPERATING MANUAL
B-3 Direct Current Current (DC Current)
Range
20µA 200µA 2mA 20mA 200mA
2A 10A 20A
Resolution
Accuracy UT51 UT 52 UT53 UT54 UT55
0.01µA (2%+5)
0.1 µA (0.8%+1)
1 µA 10µA
(0.8%+1)
100 µA
(1.5%+1 )
1mA
(1.5%+1)
10mA
(2%+5)
(2%+5 )
Overload protection:
For UT51: 2A, 250V fast acting fuse, 5x20mm(below 2A range) 10A, 250V fast acting fuse,5x20mm(at 10A range) . For UT52/53/54/55: 315mA, 250V fast acting fuse, 5x20mm (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.
6
Model UT51-55: OPERATING MANUAL
B-4 Alternating Current Current (AC Current)
Range
200µA 2mA 20mA 200mA 2A 10A 20A
Resolution
0.1µA 1µA 10µA 100 µA 1mA
10mA
Accuracy
UT51 UT 52 UT53 UT54 UT55 (1.8%+3)
(1%+3) (1%+3) (1.8%+3)
(1.8%+3) (3%+7)
(3%+7 )
Overload protection: For UT51: 2A, 250V fast acting fuse, 5x20mm(below 2A range) 10A, 250V fast acting fuse,5x20mm(at 10A range) . For UT52/53/54/55: 315mA, 250V fast acting fuse,5x20mm (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. Measuring voltage drop: Full range is 200mV. Display: Average Value (RMS of Sine Wave ) .
7
Model UT51-55: OPERATING MANUAL
B-5 Resistance
Range
200 2K 20K 200K 2M 20M 200M
Resolution
Accuracy UT51 UT 52 UT53 UT54
UT55
0.1
(0.8% +3)
1
10 100
(0.8% +1)
1K
10K
(1% +2)
100K
[5%(-10) +10]Voltage at open circuit: 700mV (200M range, open circuit voltage around 3V) . Overload protection: All ranges 250VDC or AC RMS . Caution: At 200M range, as test lead is short circuit the LCD display 10 digits is normal, deduct the 10 digits from the measured reading during measuring.
B- 6 Capacitance
Range
2nF 20nF 200nF 2µF 20µF
Resolution
Accuracy UT51 UT 52 UT53 UT54
UT55
1pF
10pF
100pF
(4% +3)
1nF
10nF
Testing signal: around 400Hz 40mVrms
B-7 Frequency
Range
2kHz 20kHz
Resolution
UT51
UT52
Accuracy UT53 UT54
UT55
1Hz
(2%+5)
10Hz
(1.5%+5)
8
Model UT51-55: OPERATING MANUAL
Input sensitivity: 100mVrms. Overload protection: 250Vrms.
B-8 Temperature
Range
Resolution
Accuracy UT51,52,53 UT53
UT55
-20oC -20oC to 0oC
to 0oC to 400oC
1oC
(5%+3) (1%+3)
1000oC 400oCto 1000oC
2%
B-9 Diode Test and Continuity Beeper
Range
Comment
Measuring Condition
Display diode forward- Forward DC current abt
voltage near value, 1mABackward DC voltage
Unit” mV”
abt 2.8V
Voltage at open circuit abt 2.8V
” ”
Overload protection: 250V DC or AC RMS.
B-10 Transistor hFE test
Range Comment
Measuring Condition
hFE
Can measure NPN or PNP transistor hFE.
Range: 0-1000
Basic polarity current abt 10µA,Vce abt 2.8V
9
Model UT51-55: OPERATING MANUAL
C. Making Measurements ” ”
” ”
1 On/Off Switch 3 Liquid Crystal Display 5 Rotary switch 7 Input jack
2 Capacitance jack 4 Temperature jack 6 Transistor jack
10
Model UT51-55: OPERATING MANUAL ” ”
” ” ” ”
Caution
” ” ” ”
” ” ” ”
” ”
Caution
”
”
” ”
11
Model UT51-55: OPERATING MANUAL
”
”
” ” ” ”
Caution ” ”
” ”
”
”
” ” ” ”
Caution 1) Please refer to DC Current Caution 1, 2, 3.
12
Model UT51-55: OPERATING MANUAL
C-5 Measuring Resistance
” ” ” ”
”
”
Caution ” ”
” ”
C-6 Measuring Capacitance Before measuring capacitance, remember it takes time for zeroing when changing ranges. Floating reading does not effect accuracy.
1) To avoid damage of the Meter or the equipment under testing, disconnect circuit powers and discharge capacitors before measuring capacitance.
2) Connect capacitor to the capacitance jack. 3) Stabilizing reading takes some time when
measuring high capacitance. 4) Unit: 1pF=10-6µF, 1nF = 10-3µF
13
Model UT51-55: OPERATING MANUAL
C-7 Measuring Frequency ” ”
” ” ” ”
” ” ” ”
” ”
14
Model UT51-55: OPERATING MANUAL
D. Maintenance I. General Service
”
” ” “” ” ” ”
15
Model UT51-55: OPERATING MANUAL
2. Turn the Meter power OFF 3. Remove the holster from the Meter. 4. Remove rubber feet and screws from the case
bottom, and separate the case bottom from the case top. 5. Remove the battery from the battery compartment. 6. Replace the battery with a new 9V battery (NEDA 1604 or 6F22 or 006P). 7. Rejoin the case bottom and case top, and install the screws and rubber feet.
III.Replacing the Fuses Caution
To avoid electrical shock or arc blast, or personal injury or damage to the Meter, use specified fuses ONLY in accordance with the following procedure. To replace the Meter’s fuse: 1. Disconnect the connection between the testing
leads and the circuit under test, and remove the testing leads away from the input terminals of the Meter. 2. Turn the Meter power OFF. 3. Remove the rubber feet and screws from the case bottom, and separate the case bottom from the case top. 4. Remove the fuse by gently prying one end loose, and then take out the fuse from its bracket. 5. Install ONLY replacement fuses with the identical type and specification as follows and make sure the fuse is fixed firmly in the bracket. UT51: 2A, 250V fast acting fuse,5x20mm (below 2A range) 10A, 250V fast acting fuse,5x20mm (at 10A range)
16
Model UT51-55: OPERATING MANUAL
UT52/53/54/55: 315mA, 250V fast acting fuse, 5x20mm 6. Rejoin the case bottom and the case top, and install the screw and rubber feet Replacement of fuses is seldom required. Burning of a fuse always results from the improper operation.
E. Accessories
1. A book of users manual 2. A pair of test lead 3. A pair of WRN-01B bread temperature probe
(for UT53 and UT55 ONLY) 4. A piece of holster (if selected)
F. Using Holster
Three different ways to use holster:
1. Set holster parallel on the table, do not open the tilt stand (see diagram 1).
2. Set holster in a small angle on the table, tilt it up by the first part of tilt stand (see diagram 2)
3. Set holster in a large angle on the table, tilt it up by all two parts of tilt stand (see diagram 3).
figure1
figure2
figure3
17
Model UT51-55: OPERATING MANUAL
G. Using Strap 1. Put the front end of the strap through the round
metal of the Meter, see part 1 of the below diagram. 2. Put the bottom end of the strap through the front part and tide it up, see part 2 of the below diagram.
~ END ~ * The manual is subject to changes without separate notice. *
18
Model UT51-55: OPERATING MANUAL 19
Model UT51-55: OPERATING MANUAL
Manufacturer: UNI-TREND TECHNOLOGY(DONG GUAN)LIMITED Address: Dong Fang Da Dao, Bei Shan Dong Fang Industrial
Development District, Hu Men Town, Dong Guan City, Guang Dong Province, China Headquarters: Uni-Trend International Limited Address: Rm901, 9/F, Nanyang Plaza 57 Hung To Road Kwun Tong Kowloon, Hong Kong Tel: (852) 2950 9168 Fax: (852) 2950 9303 Email: [email protected] http://www.uni-trend.com
20
#1 in Cloud Security & Endpoint Cybersecurity | Trend Micro
Home - UNI-T | Measurement Meters, Testing Instruments and Thermal Imaging
