Radiometric Aspects of an Experiment to Determine the Melting/Freezing Temperature of Gold

Abstract
This paper describes a radiometric determination of the melting/freezing point of gold by measurement of the spectral radiance of a black body at that temperature. A simple optical system was used to image the black-body aperture onto a filter radiometer. The advantages and disadvantages of this approach are discussed. The techniques to characterize the optical system are described together with the assessment of uncertainties. The freezing point of gold was found to be 1 337,330 K +/- 28 mK.