Device null in order to execute infrared radiation measuring method and its manner in the infrared spectrum device which uses the interferometer

摘要

PURPOSE:To enable accurate measurement of brightness by measuring infrared radiation from a reference sample with temperature thereof differing from each other in addition to a sample to calculate emissivity and brightness of the sample from the resulting three measured values. CONSTITUTION:The perimeter of a sample 1 is covered with a black body cover 3 with a brightness (radiation energy intensity) K'. Infrared radiation is measured by switching mirrors m2 and m8 and an interferometer and a detec tor respectively for the sample and reference samples S1 and S2 with emissivities thereof of epsilon1 and epsilon2 to determine measured values M, M1 and M2. Brightnesses from the black body with the temperature thereof the same as the samples 1 and S1 and S2 are put at K0, K10 and K20 and an emissivity of the sample is determined from a formula epsilon={epsilon1(K10-K')(M-M2)-epsilon2(K20-K ')(M-M1)}/(M1-M2)(K0-K'). The brightness K of the sample 1 is determined by K=epsilonK0. Thus, effect of radiation from a background is removed by measur ing infrared radiation of the samples S1 and S2' thereby enabling calculation of a true emissivity and the brightness K of the sample 1.