Introduction to the method of measuring circuit short circuit, open circuit and leakage with multimeter
1. Measure short circuit with multimeter
Operation method:
Insert the black test lead of the multimeter into the "com" hole, insert the red test lead into the "VΩ" hole, and turn the knob to the buzzer position.
Disconnect the power supply of the tested line, and test the two lines of the line with two test leads. If the resistance of the multimeter shows 0 and there is a beep, it means that there is a short circuit in the line.
Or use the ohm 1k file or 10k file, disconnect the other end of the line, and test the two lines with two test leads. If the resistance of the multimeter shows 0, it means that there is a short circuit in the line.
2. Multimeter to measure open circuit
Operation method:
When testing the continuity of the line, be sure to disconnect the power before testing.
Turn the knob switch to the buzzer position, and test that the two ends of the line are in contact with the metal needles of the test pen. If there is a certain resistance and there is a buzzing sound, it means that the line is connected; if the resistance is infinite, it will be displayed as 1. And there is no beep, the line is disconnected.
Or select the 10k range of the multimeter, short the other end of the line, and test the two lines with the test leads of the multimeter. If the resistance of the multimeter shows 1, it means an open circuit; if it shows 0, the line may be connected.
3. Multimeter to measure leakage
There is leakage in the line, it is generally not recommended to use a multimeter to test, if there is no other measuring tool, it is also possible to use a multimeter.
Operation method:
Rotate the multimeter to the AC voltage position, measure with electricity, and measure the metal casing of the equipment suspected of leakage.
When measuring, one test lead is connected to the shell, and the other test lead is grounded. If the displayed voltage is higher than 30V, test again. If the power supply is confirmed to be higher than 30V, it means that there is leakage. Generally, it is normal if it is lower than 30V. You can also connect the neutral line , After reversing the tip of the live wire meter, it can be confirmed by measuring it once.
