& nbsp; & nbsp; & nbsp; & nbsp; 1. Temperature has a great influence on insulation resistance. Generally, insulation resistance decreases with the increase of temperature. The reason is that when the temperature rises, the polarization in the insulating medium increases and the conductance increases, which results in the decrease of the insulation resistance. It is also related to the degree of temperature change and the properties and structure of insulating materials. Therefore, the temperature must be recorded in order to convert it to the same temperature for comparison.

2. The influence of humidity: moisture is absorbed on the insulating surface, and water film is formed on the surface of the ceramic sleeve, which often causes the insulation resistance to decrease significantly. When the relative humidity is high in the air, it absorbs more moisture, increases conductance and also reduces the value of insulation resistance.

3. The influence of discharge time: after each insulation test, the full discharge should be tested, and the discharge time should be longer than the charging time, so as to make the residual charge into the whole. Otherwise, the charging current and the absorbing current will be smaller than that of the first measurement due to the influence of the charge, which will result in the false phenomenon of the increase of the absorptive specific insulation resistance. When testing the cable, the absorptive specific insulation resistance will be increased. This happens.

4. Analysis and judgment: insulation status of high voltage electrical equipment with large capacitance, such as cable, transformer, generator, capacitor, etc. The absorptive ratio is the main criterion. If the absorption ratio decreases significantly, the insulation will be damped or the oil quality will be seriously deteriorated.