Integrating Sphere for Imperfectly Diffuse Samples*

Abstract

An integrating sphere for determining spectral reflectance and transmittance as a function of angle of incidence and wavelength in the 0.33- to 2.5-μ region is described. Geometrical arrangement of sample, entrance port, and detector as well as directional characteristics of detector and sphere wall coating permit absolute or relative measurements to be made for a sample with an arbitrary reflection-distribution function.