We conducted a series of spectral extinction measurements on a variety of aerosolized chemical and biological simulants over the spectral range 3–13 μm using conventional Fourier-transform IR (FTIR) aerosol spectroscopy. Samples consist of both aerosolized particulates and atomized liquids. Materials considered include Bacillus subtilis endospores, lyophilized ovalbumin, polyethylene glycol, dimethicone (SF-96), and three common background materials: kaolin clay (hydrated aluminum silicate), Arizona road dust (primarily SiO2), and diesel soot. Aerosol size distributions and mass density were measured simultaneously with the FTIR spectra. As a result, all optical parameters presented here are mass normalized, i.e., in square meters per gram. In an effort to establish the utility of using Mie theory to predict such parameters, we conducted a series of calculations. For materials in which the complex indices of refraction are known, e.g., silicone oil (SF-96) and kaolin, measured size distributions were convolved with Mie theory and the resultant spectral extinction calculated. Where there was good agreement between measured and calculated extinction spectra, absorption, total scattering, and backscatter were also calculated.
© 2004 Optical Society of America
Original Manuscript: January 15, 2004
Revised Manuscript: May 14, 2004
Published: August 10, 2004
Kristan P. Gurton, David Ligon, and Rachid Dahmani, "Measured infrared optical cross sections for a variety of chemical and biological aerosol simulants," Appl. Opt. 43, 4564-4570 (2004)