Patent ID: 8184302

Claim:
A measuring system for optical monitoring of coating processes in a vacuum chamber, particularly for layer thickness measurement of layers applied to substrates during the coating process, the system comprising: a light sender, a light-receiver unit arranged in an optical path of the light sender and a substrate carrier that can be moved in the vacuum chamber with at least one substrate, by which at least one substrate can be positioned in the optical path between the light sender and the light-receiver unit, wherein the light sender inside the vacuum chamber is arranged between the substrate carrier and a shutter, the shutter is arranged underneath the substrate carrier, whereby the shutter shades off a measuring area, wherein the substrate carrier revolves about an axis, whereby at least one substrate is arranged on a radius of the substrate carrier; and wherein the substrate carrier has at least one opening to clear a reference light path between the light source and the light-receiving unit, whereby the opening is arranged on the same radius as the substrate.