Variation in length of gauge blocks calibration using interferometry technique and machine vision

A Michelson interferometer method for determining the variation in length of gauge blocks is presented. This method is based on phase shift interferometer measuring a fringe fraction of the interference fringes on a gauge block measuring surface and its auxiliary plate. The reference standard of measurement is the wavelength of stabilized He-Ne Laser at 633 nm which is traceable to the international standard of the metre. The system was also verified by the 543 nm stabilized He-Ne Laser. The interference fringe patterns are observed by a CCD camera and the images are processed by a Machine Vision system. This make the system run automatically and fulfill. The measurement results were compared with the standard method and they agree with comparable uncertainty.