— Manufacturer of dynamic —
1, insulation resistance will decrease with the increase of temperature, this is because the temperature is too high will make the resistance dielectric intensification, and then lead to the increase of conductance and resistance reduction.
2, the insulation resistance surface moisture absorption or the formation of a water film on the porcelain insulation surface will also make the insulation resistance is reduced, in addition, when the insulation resistance in the relative humidity is high, it will absorb more water, which will also make the conductance increase to reduce the insulation resistance。
3, insulation resistance measurement is equal to the DC voltage applied on the insulation，That is to charge the subject，After the measurement, the measurement body should be fully discharged and the discharge time should be greater than the charging time, so that the charging current and absorption current obtained during repeated measurement will be smaller than the previous measurement value because the remaining electricity is not released，Thus the absorption ratio decreases and the insulation resistance value increases the illusion.
The metal FITTINGS manufacturer confirms HERE that the FACTORS affecting the measurement results of the insulation resistance of electric metal fittings are mainly caused by discharge time, temperature and humidity.