Four-band fiber-optic radiometry for determining the "true" temperature ofgray bodies

Standard radiometric thermometry is based on measuring the infrared radiati on emitted from a body in one broad spectral band. However, the "true" temp erature, T-body, can not be determined accurately if the emissivity, epsilo n, and the ambient temperature, T-room, are not known or change during the measurement. We constructed a "four band" fiber-optic radiometer for measur ement of T-body near room temperature, where measurements of the emitted ra diation were carried out in four spectral bands. The radiometer was analyze d theoretically, and was then calibrated and tested on black and gray bodie s. Good correlation between theory and experiment was achieved. (C) 2000 Am erican Institute of Physics. [S0003-6951(00)02345-7].