First, there is a problem with the use of insulation resistance testing equipment. If the testing equipment is used improperly, there is of course no way to obtain high-precision data. Before testing, the instrument should be prepared to cut off the power supply of the equipment and prepare for grounding. Before testing, it is necessary to check whether the instrument can work normally. The megohmmeter should be in the "0" position when it is short-circuited and it should be in the open circuit. "∞" position. When testing, the instrument should be placed steadily and the wiring must be accurate.

Second, the factor that affects the accuracy of the insulation resistance measurement is the cable. If the cable is used for a long time, is overheated or damp, its insulation resistance will be greatly reduced, so it is reasonable that the measurement data is not accurate.

Third, there is also the problem of measurement time that affects the accuracy of the insulation resistance measurement. In the actual measurement work, it takes a certain time for the measured electrical current to reach a stable value. At the beginning, it is a peak value, and then it will be slow. Decrease slowly, if the measured electrical resistance value is higher, the longer it will take to reach a stable and balanced value. Therefore, in order to obtain an accurate resistance value, the insulation resistance data is basically read after one minute of wiring. However, if the capacitance current of the device under test is large, or the length of the cable is long, one minute is obviously not enough. Therefore, it is necessary to read the data based on facts. Try to wait for the data to stabilize before reading, and the series resonance

In the actual operation of insulation resistance measurement, the operation manual of the insulation resistance tester should be strictly followed, and the operation should be standardized according to the actual situation of the equipment under test. Only in this way can comparative data be obtained.