A Two-Channel Scanning Spectrophotometer for Use in Studies of Collision Broadening and Shift in Optical Spectra

Abstract

A two-channel scanning spectrophotometer is described which has been used, in conjunction with a high resolution grating spectrograph, to make measurements of collision broadening and shift in optical absorption spectra to an accuracy of 0.001 cm⁻¹. Shifts with respect to a reference spectrum are measured directly from the chart of a two-pen recorder, while profiles are recorded on punched paper tape ready for computer analysis. Errors which might arise from intensity fluctuations in the light source or from non-linearity of the scanner motion are completely eliminated.