Developing the laser corrosion monitor

A personal account is given of one man's involvement in the development of a laser corrosion monitor used to measure oxide thicknesses from ten to several hundred micrometers on various nuclear reactor components. The monitor uses a free running ruby laser, water-cooled to keep its temperature below 200C, in a water-cooled container together with a helium-neon laser and auxiliary equipment. The design of the monitor, trials at Hinkley Point, small batch production, the present state of development and future developments are discussed. (U.K.)