Use of the laser interferometer for length measurement in production engineering

The physical principles of laser interferometry are introduced, and the alternating voltage and direct voltage methods are outlined. Uncertainties concerning measurement of the temperature of the unit tested, transmission of measurement value, and the laser interferometer itself are discussed. Application to pitch measurement on threaded spindles is illustrated. The system permits length measurement based on the wavelength of the light source, e.g., 0.633 microns for a red light helium-neon laser.