Absolute Spectral Radiometric Determination of the Thermodynamic Temperatures of the Melting/Freezing Points of Gold, Silver and Aluminium

Abstract

Narrow band filter radiometers have been used to measure the spectral radiance of black bodies held at the melting/freezing points of aluminium, silver and gold with an accuracy of 0,04%. Descriptions are given of the optical components and the techniques used for their characterization. As the measurements are absolute, the thermodynamic temperatures of these points can be calculated directly from the Planck radiation law. The values obtained are: