How to use a multimeter to check the circuit
When charged, use the AC voltage gear or the DC voltage gear depending on the situation! Use electrical blocking to detect circuit passes and shorts without dots!
The multimeter has a buzzer block, which is to use two test pens to measure the same wire. If there is a short circuit, there will be no response. If it is a channel, there will be a buzzing sound. Sometimes when the device itself is charged due to poor grounding, you can use the red test pen of the multimeter to put the black mark on the shell. Compared with direct contact with the ground, the strength of the leakage current of the casing can be measured, so that it can be used in the rest of the work. It is also connected in series to the circuit to measure the AC and DC current.
To check whether the circuit is leaking or not, you must use a megohmmeter (shake meter), because the voltage of the multimeter is lower (9v), and the voltage of the megohmmeter is higher than 500v. Because the working voltage of the line is 220v, it is not easy to diagnose the line with no obvious leakage. If you want to use the digital meter to check the circuit leakage, you first need to cut off the power supply. After discharging the circuit, use the resistance gear, 2M gear to measure, the normal display is 1 (infinite).
To measure whether the line is connected, you can measure it with the ohm gear of a multimeter. When measuring, it is necessary to select the meter pointer close to the deflection 0 ohm file. If the line is in the circuit, connect one end of the line (end A) to the 100 ohm range of the multimeter (red test lead), and connect the black test lead to the other end (end B) of the line to be measured. If the measured result is zero, it means this The line is connected, also called the path, only the path can the current pass through the circuit; if the ohmmeter pointer of the multimeter is not close to zero ohm from the A end to the B end of the line, the line is already in the open state, and the disconnection is called. open circuit or open circuit.
