Abstract: An automated test system is provided for evaluating characteristics of photoreceptors used in the electrophotographic process. The test system includes a retainer for holding the photoreceptor, typically in the form of a cylinder or drum, high voltage power supplies, a charging device, light sources, and non-contact electrostatic surface potential probes, the entirety of the test system enclosed in a light-proof cabinet. A control unit responsive to user defined parameters automatically performs tests for drum substrate surface cleanliness, photoreceptor layer thickness, physical defects, and electrophotographic properties. Linear and circular scanning and fixed adaptable systems are shown.