Multiplexed fiber optic collector for FTIR reflectance and radiance spectroscopy

Recently, solar furnaces have been successfully used to harden steel, coat metals, and initiate physical and chemical vapor deposition. Successful development of this technology requires process monitoring of surface temperature, which can be in excess of 2000 degree(s)C. This severely limits the accuracy of standard devices. This paper describes the use of FT-IR spectroscopy to measure spectral reflectance and radiance of solar-heated samples in order to accurately determine their temperature. The system features a fiber optic arrangement, representative of a hemispherical mirror, to collect diffusely reflected radiation. Preliminary results are given.