There are a lot of people know that the silicone waterproof sealing ring, but for what absorption characteristics, it is completely unknown.

Every insulating material is not completely nonconductive, and a tiny current will pass through it when it meets a voltage. When a dc voltage is applied to a solid insulating medium, a tiny current, which decreases with time and eventually stabilizes, is passed through. This current can be divided into three parts.

1. Leakage current

The insulating medium contains a small number of weakly bound ions or electrons, which move in a directional direction under the action of an external electric field to form a current. The size of the leakage current has nothing to do with time, and whether the insulation is damp inside, whether the surface is clean and other factors.

2. Capacitive current

At the initial moment when the dc voltage is applied, the electrons or ions of the medium are displaced by the external electric field, resulting in a capacitive current that decays very rapidly. The magnitude of this current depends on the geometric capacitance of the insulating material.

3, absorb current

When the dc voltage is added, the polarization current caused by the rotation of the dipole of the medium, and the polarization current caused by the polarization of the sandwich caused by the heterogeneity of different media or media, is called the absorption current.

Since the insulation resistance is inversely proportional to the current, the total current decays with time and the insulation resistance rises with time until it stabilizes at a value determined by the leakage current. This process is called absorption properties of insulation resistance.