This paper describes a simple and relatively inexpensive modification of the Perkin-Elmer Model 112 spectrometer for use as a grating instrument. The grating spectrometer has been used to 180 cm-1 wave-numbers in single-pass operation and in double-pass use data have been obtained to 260 cm-1. The wavenumber spread at 200 cm-1 was about 1.5 cm-1; this is gratifying in that the original thermocouple detector was used.
Robert J. Bell and T. E. Gilmer, Jr., "A Simple Grating Spectrometer for the Infrared," Appl. Opt. 4, 157-159 (1965)