HEAT CONSTANT MEASURING INSTRUMENT BY LASER FLASH METHOD

摘要

PURPOSE:To reduce a heat leak from a sample and to improve the reliability of a heat constant measured value by controlling a laser oscillator, a power source, etc., according to the detected temperatures of a sample and a shield member so that the both are at the same temperature. CONSTITUTION:A condenser lens 46, the metallic shield member 50, thermocouples 28, and 52A-52C, a power source 60, etc., are provided. Then laser light 12 is converged by the lens 46, etc., the periphery of a sample 10 is covered with the member 50, and the laser light 12 is passed through a small hole 48 as an optical path formed on the incidence side of the member 50 for the laser light 12 to heat the sample 10. A sideward and a vertical heat leak from the sample 10 are reduced by the member 50, whose temperature is detected; and a timing circuit 62 controls the laser oscillator 16, power source 60, etc., according to the temperatures of the sample 10 and member 50 so that the both are at the same temperature. Thus, the heat leak from the sample 10 is reduced to improve the reliability of the measured heat constant.