CALIBRATION OF REFLECTANCE STANDARDS.

Abstract

Measurements of the diffuse spectral reflectance are usually not made as direct measurement of the incident and the reflected radiant flux but rather as measurements relative to a standard of known reflectance value. For the calibration of such standards, different methods have been described in the literature. Various materials such as magnesium oxide, barium sulfate or opal glass are being used as standards. Their suitability as transfer or as working standards are discussed. The results of comparative measurements between some of the methods will be given.