基本信息
摘要：1,246,432. Polarizing apparatus. MULLARD Ltd. March 24, 1970, No. 14212/70. Heading G2J. [Also in Division G1] A temperature indicating device comprises a body 1 of birefringent material the birefringence of which varies with temperature, the body having both a polarizing layer 2 and a reflective surface 3 disposed on opposite surfaces thereof. In use, the body 1 which may be a single crystal of barium strontium niobate in the form of a thin film is located in an environment the temperature of which is required and a parallel beam of white light 4 is directed to the body through a window defined on one side of the body. The colour of the output beam 6 from the device is observed and such colour is indicative of the temperature of the environment in which the device is located. The polarizing layers 2 which may be provided with or separate from the reflective surfaces 3 may be of plastics material.
摘要附图：
