A photometric procedure using barrier-layer photocells

Abstract

A procedure is described whereby barrier-layer photocells, corrected so as to have a spectral response curve simulating the ICI luminosity curve, are used in the photometry of light sources of various colors and in the determination of the transmission factors of colored filters. The procedure involves a determination of the illumination-response curve of the cell used, a method of avoiding the difficulties incident to cell fatigue, and a means for correcting for the improper spectral sensitivity of the cell. The method of correcting for the difference between the spectral response of the cell used and the ICI luminosity curve embodies essentially the procedure recommended in 1937 by the International Committee of Weights and Measures for the photometry of light sources which differ in color. Results obtained using the recommended procedure are given.