An electrostatically charged object approaches or contacts another object, and as long as there is a potential difference between them, an 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 illuminating form: corona discharge, brush discharge, spark discharge and surface discharge which can be observed along the surface of charged objects.
(a) Corona discharge: Corona discharge is a discharge phenomenon in which electric fields are concentrated on some protruding parts of a charged body or a grounded body when the electric field is unevenly distributed. It is a weak tip discharge phenomenon.
(b) Brush-shaped discharge: Brush-shaped discharge is a kind of corona discharge, and most of them occur in an uneven electric field, especially when the charged electric charge is large and the shape of the charged body and the grounding body are relatively smooth, the brush-shaped discharge is likely to occur. It is accompanied by a stronger light and cracking sound than corona discharge.
(c) Spark discharge: Spark discharge is a kind of discharge with strong illuminating and rupture sound. Linear strong light can be seen between the charged body and the grounding body. In the illuminating path, it will emit several amps or more. Peak current. This discharge is likely to occur when the shape of the charged body and the grounded body is relatively smooth. When the static electricity charged by the charged body is large, spark discharge always occurs, which tends to become a source of ignition and detonation.
(d) Surface discharge: When a large amount of static electricity is present on the insulator, discharge occurs along the surface of the insulator while discharging, and this discharge form is called surface discharge. When the surface charge density of the charged body exceeds 10 C/cm 2 , the surface discharge phenomenon on the surface of the insulator can be seen. In addition, when one side of the charged body has a grounding body and the other side has a grounding body close to it, surface discharge is likely to occur. Since it has the same discharge energy as the spark discharge, it should be taken seriously.
