1. In most cases, the damage to the digital multimeter is caused by the wrong measurement gear. For example, when measuring AC mains power, the measurement gear is placed in the electrical barrier. In this case, once the test leads contact the mains power, it will cause damage in an instant. The internal components of the multimeter are damaged. Therefore, before using a multimeter to measure, be sure to check whether the measurement gear is correct. After use, set the measurement selection to AC 750V or DC 1000V, so that no matter what parameters are mismeasured during the next measurement, the digital multimeter will not be damaged.

2. Some digital multimeters are damaged because the measured voltage and current exceed the measurement range. For example, measuring the mains power at the AC 20V range can easily cause damage to the AC amplifier circuit of the digital multimeter, causing the multimeter to lose its AC measurement function. When measuring DC voltage, if the measured voltage exceeds the measurement range, it is also easy to cause circuit failure in the meter. When measuring current, if the actual current value exceeds the range, it will generally only cause the fuse in the multimeter to blow out and will not cause other damage. Therefore, when measuring voltage parameters, if you do not know the approximate range of the measured voltage, you should first set the measurement gear to the highest gear, measure the value and then change gears to obtain a more accurate value. If the voltage value to be measured is far beyond the maximum range that the multimeter can measure, an additional high-resistance measuring pen should be used.

3. The upper range of the DC voltage of most digital multimeters is 1000V, and the upper range of the AC voltage is 750V. Therefore, the maximum measured voltage is below the upper range of the multimeter, and generally the multimeter will not be damaged. If the upper limit range of the multimeter is exceeded, the multimeter is likely to be damaged.

4. Do not measure voltage at the current, resistance, diode or buzzer levels. When the instrument is being tested, the function switch cannot be rotated, especially when the voltage is high and the current is high.

5. If you use a multimeter to check the quality of components or measure the resistance of components in the circuit, do not allow the circuit to be charged, because the multimeter uses the internal battery of the multimeter to work. If there is electricity in the circuit, it will easily damage the internal battery of the multimeter and also cause damage to the multimeter. It will affect the measurement accuracy. If the multimeter is electrically blocked and insured, it will easily damage the electrical barrier equivalent resistance.

6. When the battery symbol appears on the screen, it means the battery is low and the battery should be replaced. After each measurement, the meter should be turned off. Regardless of use or storage, moisture and water are strictly prohibited.