A bench top instrument has been constructed which allows for the measurements of radiance, directional-hemispherical reflection, and directional-hemispherical transmission from materials at elevated temperatures from 100 to over 2000 °C. The instrument measures these radiative properties over a wide spectral range, in the near- and mid-IR, from 12 500 to 500 cm−1 (0.8–20 μm). These measurements are then processed to determine the spectral emittance of the material and the temperature at the point of measurement. The instrument has applications for (1) industrial quality control of radiative properties of processed materials; (2) research and development of new materials; (3) temperature measurement by optical techniques in the near- and mid-IR; and (4) determination of heat transfer properties of materials. This article describes the instrument and its novel components, and presents measurement results for several materials.
Decomposition products of fiberglass composites used in construc tion were identified using Fourier transform infrared (FT-IR) spectroscopy. This bench-scale study concentrated on identification and quantification of toxic species. Identifying compounds evolved during thermal decomposition provides data to develop early fire detection systems as well as evaluate product fire safety performance. Material fire behavior depends on many factors. Ventila tion, radiant heat flux, and chemical composition are three factors that can be modeled. Physical observations of composites during thermal decomposition with simultaneous identification and quantification of evolved gases offer re searchers in both material development and fire safety an advancement in the state-of-the-art for material testing. Gas analysis by FT-IR spectroscopy iden tified toxic effluent species over a wide range of composite exposure tempera tures (100 to 1000 ° C), during pyrolysis and combustion. Fiberglass composites with melamine, epoxy, and silicone resins were profiled. Formaldehyde, meth anol, carbon monoxide, nitric oxide, methane, and benzene were identified by the spectral analysis prior to physical evidence of decomposition. Toxic concen trations of formaldehyde, carbon monoxide, nitric oxide, ammonia, and hydro gen cyanide were observed as thermal decomposition progressed.
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