Accessories and Sampling Techniques for FT-IR Spectrometry

Abstract

The optics of most mid-infrared FT-IR spectrometers are designed so that absorption spectra of most samples may be measured using accessories which have been designed for grating spectrometers with relatively minor modification. The collimated beam from the interferometer is directed onto one of two off-axis paraboloidal mirrors which focus the beam at what would usually be considered as the “sample” and “reference” positions in the sample compartment of a conventional double-beam spectrometer. The beam is then refocused onto the detector. The beam can be passed through the front or back channel by simultaneously switching the position of two plane mirrors.