Resistance And Circuit Continuity Measurement; Diode Measurement - UNI-T UT15B PRO User Manual

9.3 Resistance and Circuit Continuity Measurement (See Figure 5a)
1) Turn the function selection knob to the resistance scale.
4) Insert the red test leads to the Ω port and the black one to the COM port, and connect the tips of two test
leads to both ends of measuring resistance separately (with the load in parallel) to measure.
True RMS
CAT III 1000V
CATIV 600V
Figure 5a
Note:
OL symbol will be displayed when the measured resistance is open-circuit or the resistance exceeds the
maximum range of meter.
Before online resistance measuring operation, please switch off all powers in circuit and fully discharge all
capacitors to avoid inaccuracy.
Error of 0.1Ω~0.2Ω will be resulted by test leads in low resistance measurement. In order to acquire an accurate
reading, users should short circuit the test leads and choose REL relative measurement mode.
15
UT15B PRO/UT17B PRO User Manual
True RMS A
≤
0.5 Ω OK
OL
OK
µAmA
CAT III 1000V
CATIV 600V
*1M OK
OL OK
Figure 5b
UT15B PRO/UT17B PRO User Manual
Check the test leads for any loosing or other reasons in case there is a resistance no less than 0.5Ω when
test leads are short-circuited.
Several seconds may be required for the reading stability, which is normal in high resistance measurement
like 60MΩ.
In circuit continuity measurement, the circuit is off when the resistance of both measured ends is ≥ 50Ω
without buzzer beeps. The circuit is on when the resistance of both measured ends is ≤ 10Ω with buzzer beeps
continuously.
The resistance measurement function can be applied to make self-inspection of built-in fuse (See Figure 5b).
Before online circuit continuity measurement, please switch off all powers in circuit and fully discharge all
capacitors.
Do not input voltage higher than DC 60V or AC 30V to avoid danger.
9.4 Diode Measurement (See Figure 5a)
1) Turn the function selection knob to the diode measurement scale.
2) Insert the red test leads to the Ω port and the black one to the COM port, and connect the tips of two test
leads to both ends of measuring diode separately (with the load in parallel) to measure.
3) OL symbol will be displayed if the diode is open circuit or polarity reversing. Generally, about 500~800mV is
confirmed to be normal for silicon PN junction.
Note:
Before online diode measuring operation, please switch off all powers in circuit and fully discharge all capacitors.
The voltage range of diode measurement is about 3.0V.
Do not input voltages above AC 30V or DC 60V to avoid injury.
16