Jula UT131 User manual

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UT131 Palm Size Multimeter
User Manual

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Ⅰ.Overview
The new generation UT131 series products redefine the performance standards for entry-level digital
multimeter. The innovative industrial design ensures the products have 2 meters impact resistance.
The new LCD display layout provides a clear display for better user experience. The UT131 series
ensure safe operation in CAT II 250 V environment.
The special features of each model are as follows:
UT131A: 2mF capacitance test function
UT131B: Battery test with status indicators
UT131C: Temperature test
UT131D: NCV test
Ⅱ.Open Box Inspection
Open the package box and take out the device. Please check whether the following items are
deficient or damaged and contact your supplier immediately if they are.
User manual -----------------------1 pc
Test leads ---------------------------1 pair
Protective case---------------------1 pc

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K-type Thermocouple ----------1 pc (UT131C only)
Warning:
Please carefully read “Safe Operation Rule” before using the device.
Ⅲ.Safe Operation Rule
1). Safety certification
This device strictly follows the CE standards: EN 61010-1: 2010, EN 61010-2-030:2010, EN
61326:2013, as well as CAT II: 250V, RoHS, pollution grade II, and double insulation standards.
2). Safety instructions and Precautions
1. Do not use the device if the device or test leads appear damaged or if you suspect that the
device is not operating properly. Pay particular attention to the insulation layers.
2. If the test leads are damaged, it must be replaced with one of the same type or the same
electrical specification.
3. When measuring, do not touch exposed wires, connectors, unused inputs, or the circuit being
measured.

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4. When measuring the voltage higher than 60 VDC or 30 VACrms, keep your fingers behind the
finger guard on the test lead in order to prevent electric shock.
5. If the range of the voltage to be measured is unknown, the maximum range should be
selected and then gradually decreased.
6. Never input voltage and current exceeding the value listed on the device.
7. Before switching ranges, make sure to disconnect the test leads with the circuit to be tested. It
is strictly prohibited to switch the Ranges during the measurement.
8. Do not use or store the device in high temperature, high humidity, flammable, explosive or
strong magnetic field environments.
9. Do not change the internal circuit of the device in order to avoid the damage to the device and
users.
10. To avoid false reading, replace the battery when the battery indicator appears.
11. Use dry cloth to clean the case, do not use detergent containing solvents
Ⅳ.Electrical Symbols
low battery
High voltage warning

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Electrical ground
AC/DC
Double insulation
Warning
Ⅴ.Specification
1. The maximum voltage between the input terminal and the ground: 250Vrms
2. 10A terminal: Fuse 10 A 250 V Fast fuse Φ5×20 mm
3. mA/μA terminal: Fuse 200 mA 250 V Fast fuse Φ 5×20 mm
4. Max display 1999, over range display “OL”, update rate: 2~3 times/second
5. Range select: Auto range UT131A; Manual range UT131B/C/D
6. Backlight: manual on, auto shut off after 30 seconds
7.Polarity: "-" symbol displaying on screen represents negative polarity signal.

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8. Data hold function: symbol displays on screen when data hold function is activated
9. Low battery power: symbol displays on screen when battery power is low
10. Battery: AAA 1.5V * 2
11. Operating temperature: 0~40˚C (32˚F~104˚F)
Storage temperature: -10~50˚C (14˚F~122˚F)
Relative humidity: 0˚C~30˚C: ≤75% RH, 30˚C~40˚C: ≤50% RH
Operating altitude: 0 ~ 2000m
12. Dimension: (134×77×47) mm
13. Weight: about 206g (battery included)
14. Electromagnetic compatibility:
In fields with less than 1 V/m radio frequency, the total accuracy = designated accuracy + 5% of
measurement range

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In fields with more than 1 V/m radio frequency, the accuracy is not specified.
Ⅵ. Structure (see Figure 1)
Figure 1

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1. Display screen
2. Function keys
3. Functional dial
4. 10A input jack
5. COM jack
6. Remaining inputs jack
Ⅶ.Key Functions
1) UT131A:
* SEL/REL: press this key to switch between AC and DC modes for mV , I , and REL

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positions.
* : Press to enter or exit data hold mode. Long press over 2 seconds to turn on/off
backlight.
2) UT131B/C/D:
*. HOLD/SEL: Press to enter or exit data hold mode
In continuity/diode mode, press to cycle switch between the two modes
* : Press to turn on/off backlight.
Ⅷ.Operations
To avoid false reading, replace the battery if the battery low power symbol appears. Also pay
special attention to the warning sign beside the test lead jack, indicating that the tested

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voltage or current must not exceed the values listed on the device.
1. AC/DC voltage measurement (see Figure 2b)
1) Switch the dial to “V~” position.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the load in parallel.

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Notes:
*. Do not measure voltage over 250Vrms, or it may expose users to electric shock and damage the
device. If the range of the voltage to be measured is unknown, select the maximum range and
reduce accordingly.
*. Please pay extra attention when measuring high voltage in order to avoid electric shock.
*. Before using the device, it is suggested to measure a known voltage for verification.
2. Resistance measurement (see Figure 2b)
1) Switch the dial to “Ω” position.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the resistor in parallel

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Notes:
*.Before measuring resistance, switch off the power supply of the circuit, and fully discharge all
capacitors.
*. If the resistance when shorted is more than 0.5Ω, please check if test leads are loosened or
damaged.
*.If the resistor is open or over the range, the “OL” symbol will be displayed on the screen.
*.When measuring low resistance, the test leads will produce 0.1Ω~0.2Ω measurement error. To
obtain accurate measurement, the measured value should subtract the value displayed when
two test leads are shorted.
*. When measuring high resistance above 1MΩ, it is normal to take a few seconds to steady the
readings. In order to quickly obtain steady data, use short test wires to measure high
resistance.
3. Continuity Measurement (see Figure 2b)

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1) Switch the dial to “ ” position.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the points to be tested in parallel
3) Measured points’ resistance > 51Ω, circuit is in open status.
Measured points’ resistance ≤ 10Ω, circuit is in good conduction status, buzzer will go off
Notes:
Before measuring continuity, switch off all power supplies and fully discharge all capacitors.
4. Diode Measurement (see Figure 2b)
1) Switch the dial to “ ” position.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the diode in parallel
3) “OL” symbol appears when the diode is open or polarity is reversed.
For silicon PN junction, normal value: 500 ~ 800mV (0.5 ~ 0.8V).
Notes:
*. Before measuring PN junction, switch off the power supply to the circuit, and fully discharge all

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capacitors
5. Capacitance Measurement (only for UT131A, see Figure 2a)
1) Switch the dial to capacitance test.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the capacitor in parallel
3) When there is no input, the device displays a fixed value (intrinsic capacitance). For small
capacitance measurement, to ensure measurement accuracy, the measured value must be
subtracted from intrinsic capacitance. Users can measure small capacity capacitors with relative
measurement functions (REL) (the device will automatically subtract the intrinsic capacitance)
Notes:
* If the tested capacitor is shorted or its capacity is over the specified range
“OL” symbol will be displayed on the screen.
* When measuring large capacitors, it may take a few seconds to obtain steady readings.
* Before measuring capacitors (especially for high voltage capacitors), please fully discharge them.

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6. DC Measurement (see Figure 3)
1) Switch the dial to DC test.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the tested circuit in series.
Figure 3

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Notes:
*. Before measuring, switch off the power supply of the circuit and carefully check the
input terminal and range position.
*. If the range of the measured current is unknown, select the maximum range and then
accordingly reduce.
*. Please replace the fuse with the same type.
10A jack: Fuse 10A/250V Φ5×20mm
VΩmA jack：Fuse 0.2A/250V Φ5×20mm
*. When measuring, please do not connect the test leads with any circuit in parallel.
Otherwise there is a risk of damage to the device and human body.
*. If the tested current is over 10A, each measurement time should be less than 10
seconds and the next test should be after 15 minutes.
7. AC Measurement (only for UT131A, see Figure 3)
Similar to DC Measurement.
Please refer to Section 6 “DC Measurement (see Figure 3)”

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8. Battery Measurement (only for UT131B, see Figure 4)
1) Switch the dial to battery test.
2) Insert the black test lead into the COM jack, the red test lead into the “VΩmA” jack. Connect
test leads with the battery in parallel.
Red test lead at positive pole “+”, black test lead at negative pole“-“
3) Battery status:
“Good”: Normal status
“Low”: Low power but still working
“Bad”: Replace/charge batteries
4) Battery display

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*1.5V battery
Figure 4

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Load Resistance: 30 Ω:
“Good”: Voltage≥1.31V
“Low”: Voltage 0.95V~ 1.31V
“Bad”: Voltage ≤ 0.94V
*9V battery

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Load Resistance: 900Ω:
“Good”: Voltage≥7.8V
“Low”: Voltage 5.7V~ 7.7V
“Bad”: Voltage ≤ 5.6V
* 12V battery