Spectral Emissivity of Rhenium

Abstract

The spectral emissivity of rhenium has been measured at temperatures between 1537° and 2772°C for wavelengths between 0.35μ and 2.8μ. The emissivity at 0.65μ agrees well with previous measurements for temperatures below 2200°C, and disagrees only slightly above this temperature.The method and equipment used in the measurements are discussed, and the errors are analyzed.The measured emissivities, and the temperature coefficient of emissivity are compared with the predictions of the Hagen-Rubens relation.