Applications of spectral emissometry for measurements of radiative properties of erbium oxide and quartz have been described. The spectral emissometer has also been utilized to characterize the optical properties of infrared filters. These measurements have been performed in the wavelength range of 1 to 20 microns and temperature range of 25 to 1000°C. The measured properties of erbium oxide and quartz have been compared with available optical properties in the literature. Simulation of the radiative properties of quartz has been made utilizing Multi-Rad, a PC-based software implemented in the form of the matrix method of multilayers. The relevance of these measurements has been discussed in light of thermophotovoltaics and multi-wavelength imaging pyrometry.