PHOTOMETER FOR MEASURING

摘要

An arrangement and photometer for measuring and controlling the thickness of optically active thin layers wherein the axis of the measurement light beam coming from the measurement light source is directed to the measurement object and a referenced light receiver, independent of the optical properties of the measurement object, is associated with the measurement light beam. The output signal of the referenced light receiver is mixed with a trigger stage for a phase sensitive photometer amplifier and is fed to a compensation circuit for the equilization of brightness variations in the measurement light source.