The temperature variation of the emissivity of metals in the near infra-red

Abstract

Evidence for the existence of a wave-length, peculiar to each metal, for which the temperature coefficient of emissivity is zero is analysed and commented upon. Further experimental data obtained from the author's measurements of infra-red emissivity of hot metals are submitted in support, and it is shown that the appearance of such an X-point phenomenon would explain many of the divergent results obtained for the temperature variation of emissivity in the visible region, besides providing a new series of characteristic wave-lengths for metals.