Comparator for spectroscopic measurements using an interferometer and photoelectric scanning (Cospinsca)

Abstract

A screw comparator has been modified into an automatic interference fringe counting comparator which allows determination of displacements with a precision of 0.25 micron. With a photoelectric setting device the reproducibility of setting on a photographic image of a symmetrical spectral line is about 0.5 micron. Automatic recording of fringe counting numbers and total light absorption by the line image is also provided for. The salient features of the apparatus are described and some results of measurements are discussed. © 1964 Martinus Nijhoff.