Transparent substrate transmission measuring instrument for vacuum system, has retro-reflector located on one side of plane, where main axis of retro-reflector runs vertically to plane to coincide with normal axis of plane

摘要

The instrument has a measuring head with a light emitting unit emitting a beam of light onto a substrate plane, and a light receiver unit recording an incident beam. The head and a retro-reflector are located on the two respective sides of the plane. The retro-reflector is realized as a cube corner prism made of optical glass. The light emission direction of the emitted light makes an angle (7) with a normal axis (6) of the plane, where a main axis of the retro-reflector makes an angle (7) related to the direction. The main axis runs vertically to the plane to coincide with the normal axis.