An experimental system to measure the diffuse reflectance of a particulate sample over the wavelength range of 300 to 2500 nm at elevated temperatures up to 1000°C has been developed and implemented. A description of the experimental apparatus and measurement procedures, as well as optical reflectance data for the Masterbeads®, are presented. Using the high temperature measurement system, the diffuse reflectance of Masterbeads®changed by less than 1% for sample temperatures from 150°C to 930°C. However, after heating a sample for three hours at 1000°C in air, the solar absorptance measured at room temperature decreased from an initial value of 0.93 to 0.89. © 1986.
Stahl, K. A., Griffin, J. W., & Pettit, R. B. (1986). Optical properties of solid particle receiver materials. II. Diffuse reflectance of Norton Masterbeads® at elevated temperatures. Solar Energy Materials, 14(3–5), 417–425. https://doi.org/10.1016/0165-1633(86)90063-8