A measurement device based on the radiation comparison technique is described. It enables us to measure the directional total and spectral emittance between 400°C and 1200°C in the wavelength range 0.5 μm to 8 μm and at angles of up to 72° against the normal to the surface. Measurements with different types of silica showed that the spectral emittance can be remarkably increased, especially at wavelengths below 5 μm, by adding small amounts of silicon carbide. This is important for the improvement in the efficiency of the heating at different types of furnaces. © 1993.
Neuer, G. (1993). Total normal and spectral emittance of refractory materials for high temperature ovens. Thermochimica Acta, 218(C), 211–219. https://doi.org/10.1016/0040-6031(93)80423-8