An FT -IR based instrument for measuring infrared diffuse reflectance

Abstract

The determination of the reflectance for directional irradiation of diffusely reflecting sample is important to improve the knowledge of thermal exchanges. It appears necessary to have some complete reflectivity measurements. Thus an infrared scattering instrument has been build and we have done measurements on several samples. The incidence angles range from 10· to 80·. The use of a Fourier Transform spectrometer permits measurements in the 650 cm-1 -8000 cm-1 wavenumber range (1.5 Ilm-15 11m) and the maximal spectral resolution is 0.125 cm-1. The instrument was tested on an alumina sample at room temperature. The wavenumber range is 1300 cm-1 -8000 cm-1.