The Spectropus™ system, a versatile optical sampling system for performing infrared spectroscopic analyses on remotely located samples with little regard to their size and with spectral quality and sampling rates comparable to, or better than, those achievable with spectrometer sample compartment accessories, is described. The Spectropus™ uses a "glass-tube beam-line" optical transfer system for delivering the collimated beam of an FT-IR spectrometer to one of several dedicated accessories, complete with its own detector, that may be located several meters distance from the spectrometer. The accessories include the barrel ellipsoid diffuse reflectance and emission accessory, the grazing-incidence external reflection accessory, and the gas analysis accessory. One system described here supports up to four accessories in laboratory air and another supports two accessories in two different glove boxes. Application examples include the monitoring of the formation of LiOH and LiOD on LiH and LiD in glove boxes as a result of moisture corrosion; the analysis of ink stains on paper; the analysis of inks, parylene films, and oil stains on metals; the analysis, with monolayer resolution, of oxides on aluminum foil and on uranium being oxidized in air; the analysis of wood and of graphite-epoxy composites, including the rapid sequential determination of diffuse reflectance and emission spectra from one point on one sample; and sub-part-per-million gas analyses using an evacuated cell reference spectrum that is free of pressurization stress artifacts.
G. L. Powell, M. Milosevic, J. Lucania, and N. J. Harrick, "The Spectropus™ System: Remote Sampling Accessories for Reflectance, Emission, and Transmission Analysis Using Fourier Transform Infrared Spectroscopy," Appl. Spectrosc. 46, 111-125 (1992)