How to use a multimeter to measure and evaluate AC voltage and a zero live wire
How to measure AC voltage with multimeter
1. Measurement method of AC voltage
1. Insert the black test lead into the COM jack, and the red test lead into the V/Ω jack.
2. Put the function switch in the range of AC voltage range V~, and connect the test pen to the power supply or load to be tested.
3. When measuring AC voltage, there is no polarity display.
4. Regardless of measuring AC or DC voltage, pay attention to personal safety and do not touch the metal part of the test lead casually.
Take the measurement of AC 220V as an example: turn the switch to the required voltage level during measurement (when measuring AC 220V, the switch should be turned to AC 750V).
When measuring, the test pen should be connected in parallel with the circuit under test. If you don't know the range of the voltage to be measured, you can use a larger limit test to get the approximate value first, and then turn to the corresponding limit measurement.
2. Operation tips
1. Select the AC voltage gear for the range. When the voltage range is not known, it should be selected from the maximum range.
2. The meter should be connected in parallel at both ends of the circuit or component under test.
3. Measurement steps of AC voltage
Step 1: Turn on the power switch of the digital multimeter, and turn the gear of the multimeter to the AC voltage range of 750V.
Step 2: Turn on the power switch in the circuit.
Step 3: Measure the voltage between points 1-2 and record the reading. The measured voltage value is 220V.
Step 4: Turn the gear of the multimeter to the AC voltage range of 20V, measure the voltage between points 3-4, 4-5, and 6-7, and record the readings.
4. Matters needing attention
1. If the measured voltage range is unknown. Set the function switch to the maximum range and gradually decrease.
2. If the display only shows "1.", it means the range is too small, and the function switch should be set to a higher range.
3. "" means do not measure voltages higher than 1000V. It is possible to display higher voltage values, but there is a danger of damaging the internal circuits.
4. When measuring high voltage, pay special attention to avoid electric shock.
