Influence of Thickness and Dielectric Material on Surface Charge Decay in atmospheric air

Surface charge decay on various dielectric materials in atmospheric air was studied. In the experiment, a dielectric circular disc placed on a plane electrode in a rod-plane air gap was charged by positive or negative DC corona discharge. The dielectric discs with a thickness of 0.05, 0.2, 0.5 and 1.0 mm made of polyethylene terephthalate (PET) and the dielectric discs with a thickness of 1.0 mm made of acrylic and glass epoxy multilayer have 200.0 mm in diameters. The surface potential induced from accumulated surface charge was measured by an electrostatic voltmeter which can be controlled automatically by a computer at 5.0 mm intervals in the direction of X and Y axis. The charged dielectric discs were stored in air-conditioned room. The temporal decay of surface potential distribution…