Four methods for the measurement of absolute reflectance are described and compared, with particular emphasis on application to transmissive materials such as windows and filters. Three of the methods, the V-W , V-N , and goniometer based methods, have been in use for a number of years. The fourth is an integrating sphere method. The sphere system is used for both specular and diffuse samples but achieves its greatest accuracy in the measurement of specular reflectance and transmittance. A direct comparison of the sphere and goniometer methods is made on samples in the infrared spectral region.
Citation: SPIE International Society for Optical Engineering
Pub Type: Journals
goniometer, infrared, integrating sphere, reflectance, v-n method, v-w method