The most common digital multimeters generally have resistance measurement, on-off sound detection, and diode forward voltage measurement. AC and DC voltage and current measurement, transistor magnification and performance measurement, etc. Some add functions such as capacitance measurement, frequency measurement, temperature measurement, data memory and voice report, which bring great convenience to the actual detection work. However, due to improper use of the digital square meter, it is easy to cause damage to the components in the meter during actual detection and malfunction. The precautions for the digital square meter in use are for beginners and beginners to reference, in order to prevent the damage of the digital multimeter as much as possible.

Digital multimeter failure reasons and preventive measures:

1. The damage of the digital multimeter is caused by the wrong measurement gear in most cases. For example, when measuring the AC mains, the measurement gear is selected to be placed in the electric block. In this case, once the pen touches the mains, it will cause the multimeter in an instant. Internal components are damaged. Therefore, before measuring with a multimeter, be sure to check whether the measurement gear is correct. After use, place the measurement selection at AC 750V or DC 1000V, so that no matter what parameters are wrongly measured during the next measurement, it will not cause damage to the digital multimeter.

2. Some digital multimeters are damaged due to the measured voltage and current exceeding the range of the measurement range. If the mains power is measured in the AC 20V range, it is easy to cause damage to the digital multimeter's AC amplifier circuit and make the multimeter lose its AC measurement function. When measuring DC voltage, the measured voltage exceeds the measurement range, which is also easy to cause circuit failure in the meter. When measuring the 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 the voltage parameters, if you do not know the approximate range of the measured voltage, you should first place the measurement gear at the highest level, and then measure the value and then shift the measurement to get a more accurate value. If the value of the voltage to be measured far exceeds the maximum range that the multimeter can measure, a high-resistance measuring pen should be additionally equipped. Such as detecting the second anode high voltage and focused high voltage of black and white color TV.

3. The upper limit of the DC voltage range of most digital multimeters is 1000V, so when measuring the DC voltage, the maximum voltage value is below 1000V, and generally the multimeter will not be damaged. If it exceeds 1000V, it may cause damage to the multimeter. However, the upper limit of the measurable voltage of different DMMs may be different. If the measured voltage exceeds the range, the method of resistance voltage reduction can be used for measurement. In addition, when measuring a high DC voltage of 40O-1000V, the test leads must be in good contact with the measurement place without any jitter, otherwise, in addition to the possibility of damage to the multimeter and inaccurate measurement, it can also make the multimeter without any serious display.

4. When measuring resistance, be careful not to measure live. (Organized by China Educational Equipment Purchasing Network)