The method of measuring the zero line of the digital multimeter
1. Turn the switch of the multimeter to AC 250V or 500V, and connect one of the test leads to the power supply and the other to the ground (such as a water pipe or a damp place).
2. When the reading of the multimeter is close to 220V, the measured point is the live wire.
3. If the needle does not move, reduce the switch of the multimeter to the lowest gear step by step, and there is still no obvious reading, then the measured point is the zero line.
4. If there is no grounding place, you can use the method: turn the switch of the multimeter to the highest level of AC voltage, connect any test lead to the measured point of the power supply, and pinch the other test lead with the index finger and thumb of the hand. If the multimeter reads, The measured point is the live wire; if the pointer of the multimeter does not move, it is the zero wire or the ground wire.
