Disclosed herein is a method and apparatus for controlling surface characteristics by measuring capacitance of a process kit ring. The method includes interfacing a ring with a jig assembly for measuring capacitance in at least a first location of the ring. The ring has that includes a top surface, a bottom surface, and an inner surface opposite an outer surface. At least the bottom surface has an external coating placed thereon. The method further includes contacting a measuring device to the first location on the outer surface proximate the bottom surface. The measuring device contacts an opening in the external coating to the body. The measuring device contacts a first conductive member that is electrically coupled to the ring. A capacitance is measured on the measuring device. The capacitance across the top surface is measured.