What kinds of discharge phenomenon are there in static electricity?

An electrostatically charged object approaches or contacts another object, and as long as there is a potential difference between them, electrostatic charge transfer occurs. This process of electrostatic charge transfer is called electrostatic discharge.

Electrostatic discharge can be roughly divided into four types according to its light emitting form: corona discharge, brush discharge, spark discharge, and surface discharge that can be observed along the surface of a charged object.

(A) Corona discharge: Corona discharge is a discharge phenomenon that occurs when the electric field is unevenly distributed, and the electric field is concentrated on some protruding parts of the charged or grounded body. It is a weak tip discharge phenomenon.

(B) Brush-shaped discharge: Brush-shaped discharge is a type of corona discharge, which mostly occurs in an uneven electric field, especially when the charged charge is large and the shape of the charged body and the ground body is relatively smooth. Accompanied by stronger light and crackling sounds than corona discharge.

(C) Spark discharge: Spark discharge is a kind of discharge with strong light emission and cracking sound. A linear strong light can be seen between the charged body and the ground body. In the light-emitting path, it will instantly emit more than several amperes. Peak current. When the shapes of the charged body and the ground body are relatively smooth, such discharge is liable to occur. When the static electricity of a charged body is relatively large, spark discharge always occurs, and it often becomes the source of ignition and detonation.

(D) Surface discharge: When there is a large amount of static electricity on the insulator, a discharge occurs along the surface of the insulator at the same time as the discharge to the air. This type of discharge is called surface discharge. Generally, when the surface charge density of the charged body exceeds 10C / cm2, the surface discharge phenomenon on the surface of the insulator can be seen. In addition, when a charged body has a grounded body on one side and a grounded body on the other side is close to it, surface discharge is liable to occur. Because it has the same discharge energy as spark discharge, it should be paid attention to.