Optical measurement technique for determination of the wall thickness of a transparent container uses two light beams derived from an interferometer to determine the optical path lengths to a target and a reference reflector

摘要

Method in which an interferometer (2) is illuminated with polychromatic light (f1). A first light beam from the interferometer (f2) is directed towards the transparent object (7) the thickness of which is to be measured. A second reference beam (f3) is directed towards a reference reflector (8) and the optical path of the second beam is varied spatially and periodically, so that the material thickness (e) is determined by equalizing the 2 optical beam paths. An Independent claim is made for a device for non-contact measurement of the thickness of a transparent wall or sample.