Emissivity of stoichiometric zirconium carbide

Experimental data are presented on the integral hemispherical emissivity and the monochromatic emissivity for wavelength $0. 65\,\mu$m for both pure pyrolytic zirconium carbide of composition close to stoichiometric, and for stoichiometric zirconium carbide with small additions of nitrogen. It is shown that a nitrogen content of amount up to $1\%$ has no appreciable influence on the emissivity. The experimental data obtained are compared with all data available in the literature, and from this comparison recommendations are made for the most reliable values of radiative characteristics at temperatures above $1200$ K.