The Beckman spectrophotometer Model DU has proved to be a useful instrument for measuring spectral directional reflectance. Like other spectrophotometers it is subject to slit-width and stray-energy errors. The magnitude of these errors and techniques for minimizing them are discussed. The viewing geometry and an adaptor for four-inch square specimens are described.
© 1952 Optical Society of AmericaFull Article | PDF Article