Why should the shielding cover be grounded in electrostatic shielding
Measures to isolate the effects of electrostatic fields by using metal cavities. Due to electrostatic induction, the field strength inside the cavity conductor (referring to the inside of the metal conductor itself, not the area enclosed by the cavity) that achieves electrostatic balance is zero, so that the electric field outside the cavity cannot enter the cavity and is surrounded by the cavity. The area played a role of shielding and protection. If there is a charged body in the area enclosed by the conductor cavity, the cavity conductor can be grounded, and the induced charge generated by the inner charged body on the outer surface of the cavity conductor will disappear due to the grounding, so that the electric field of the charged body in the cavity cannot penetrate Penetrate to the outside, eliminating the influence on the area outside the cavity. In short, the cavity conductor eliminates the influence of the external electric field on the cavity area, and the grounded cavity conductor eliminates the mutual influence of the internal and external electric fields. This is electrostatic shielding, which is widely used in various equipment such as electrical appliances and meters. In fact, the use of metal mesh as an outer cover can provide a good shielding effect.