A precision direct-reading spectrophotometer

Abstract

The experimental errors inherent in photographic photometry are discussed and a direct reading spectrophotometer for the visible especially adapted to the study of line, contour and absorption and fluorescence spectra is described. Because of the higher resolution of which it is capable the method permits a more precise and complete analysis of absorption and fluorescence spectra by revealing the fine structure too small to be detected by the usual methods. A test of the instrument was carried out by determining the intensities of the lines 4078 and 4047 from Hg arc and the energy distribution in the Hβ of the solar spectrum. The system is distinguished by high sensitivity and easy adjustment and it dispenses with the labour involved in photographic photometry.