The evolution of absorbing surfaces for electrically calibrated radiometers, and techniques for measuring their absorptance (reflectance) are described. A new reflectometer for cavity reflectance measurements, which is based on a ring-shaped silicon photodiode, is described. The results of reflectance measurements on a series of cavities which represent the evolution of cavity technology are presented, and the significance of the results for future research are discussed.
E. F. Zalewski,
R. C. Willson,
"Cavity Radiometer Reflectance", Proc. SPIE 0196, Measurements of Optical Radiations, (15 November 1979); doi: 10.1117/12.957968; https://doi.org/10.1117/12.957968