INFRARED-SPECTRA OF GLASSES AT HIGH-TEMPE RATURE BY INVERSION OF NONISOTHERMAL SLAB RADIATIVE EMISSION

The infrared absorption spectra of silicate glasses and boric anhydrid at high temperature are worked out by means of an inverse technique o f optimization from the emission spectra. The sample's emission spectr al intensities are measured by a Fourier Transform Infra-Red spectrome ter. Specimens are plane parallel slabs which are deposited on a crusi ble. Their lower face is in contact of the crusible and isothermal but the upper one exchanges heat with the atmosphere by natural convectio n. In such conditions the glass slabs are submitted to high thermal gr adients and the optimization method used is a non-linear constainted i terative method. The resulting spectra are compared to absorption spec tra obtained by transmission spectrometry.