Two methods are developed for measuring low-temperature spectral emissivities in the infrared region. Neither of these has apparently been employed previously. One of them, which is only an approximate method, was followed by measurements of three common alloys. The values of emissivity obtained agree reasonably well with those calculated from the reflectivity data of others for similar materials.
DWIGHT WEBER, "Spectral Emissivity of Solids in the Infrared at Low Temperatures," J. Opt. Soc. Am. 49, 815-819 (1959)