Interfacing an analogue infrared spectrometer to a microcomputer

An Apple microcomputer has been interfaced to a Perkin-Elmer model 577 infrared spectrometer. The spectral data are digitized with the aid of an in-house designed 12-bit analogue-to-digital interface unit. Control and status signals are obtained from the spectrometer and an optical encoder unit is used to provide an accurate wavenumber marker for the conversion and data recording. The digital data are formatted by the microcomputer and then can be manipulated by programs already developed for handling spectral data recorded from digital spectrometers.