Abstract
Measurements of the normal spectral emissivity of Ta–W and Nb–Mo alloys are reported. The emissivities were measured at 2000°, 2200°, and 2400°K in the wavelength range 0.4 to 4 μm. The emissivities of the alloys generally lie between the values of the pure constituents. The temperature coefficient and the x‐point wavelength of Ta–W alloys change in a characteristic way. The measurements support the validity of the rigid band model.