An experiment designed to measure the spectral emissivity of tungsten, in which a direct comparison method is utilized so that the spectral emissivity is observed directly as the ratio of light intensity from a tungsten source to that from a blackbody source, is described. The spectral emissivity was measured over the wavelength interval 310 mµ to 800 mµ, and the temperature interval 1600°K to 2400°K.
ROBERT D. LARRABEE, "Spectral Emissivity of Tungsten," J. Opt. Soc. Am. 49, 619-625 (1959)