Abstract
In order to investigate the radiation heat characteristics of thermal insulations, we have developed a new apparatus to measure the diffusive reflectance and transmittance at a temperature range from room temperature to 1000 ℃ in the wavelength range from 1.28 to 25 pm. In this study, the diffusive reflectances of three kinds of thermal insulations (Alumina-silica board, Rock wool, and Calcium silicate) were measured. Those diffusive reflectances were 1% or less. Though the incident angle of the light was 15 deg. to the normal line of the specimen's surface, the reflectance intensities of these specimens were the highest values at 0 deg. and decreased with the reflection angle increasing.
