1. Influence of temperature: 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 intensifies, and the conductance increases, resulting in a decrease in the insulation resistance value. And the degree of temperature change is related to the properties and structure of insulating materials. Therefore, the temperature must be recorded during the measurement so that it can be converted to the same temperature for comparison.
2. Influence of humidity: The insulating surface absorbs moisture, and the surface of the porcelain sleeve forms a water film, which often reduces the insulation resistance significantly. When the relative humidity in the air is high, it will absorb more moisture, increase the conductance, and also reduce the insulation resistance value. .
3. Influence of discharge time: After each insulation measurement, the tested object should be fully discharged, and the discharge time should be longer than the charging time, so as to drain the remaining electric charge, otherwise, due to the influence of electric charge during heavy measurement, its The charging current and the sinking current will be smaller than in the first measurement, thus creating a false phenomenon of an increase in the absorption ratio to the insulation resistance value, which occurs when testing cables.
- Analysis and judgment: the insulation condition of high-voltage electrical equipment with relatively large capacitance such as cables, transformers, generators, capacitors, etc. It is mainly based on the size of the absorption ratio. If the absorption ratio drops significantly, it means that the insulation is damp or the oil quality is seriously deteriorated.