Noncontact surface charge density profiles measurement on top andbottom of a charged film

Equivalent surface charge density profiles on both the top and bottom surfaces of corona-charged films were measured without any contact by using a surface potential voltmeter with a horizontal resolution of about 2 mm and a laser displacement meter with a vertical resolution of 10 μm. A personal computer controls the sample position with a resolution of a few micrometers, which depends on a digital X -Y stage and a backside ground electrode position (distance from the bottom of the charged film). Surface potential profiles at a few different distances between the ground electrode (back) and the sample film were recorded on a floppy disk, and equivalent surface charge density profiles on the top and the bottom of the film were calculated and plotted automatically by using a personal computer. Some interesting electrostatic phenomena related to their charge behavior are reported as are its applications