Performance trade-off modeling for a handheld FTIR spectrometric vapor identifier

Autor: David W. Schiering, Robert G. Messerschmidt, Peng Zou, Josep Arnó
Rok vydání: 2010
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
Popis: Emerging chemical threats to homeland security challenge the specificity of sensor-based chemical detectors. As the number of chemicals to detect increases, the false alarm rates of these sensor-based systems tend to increase and the usefulness of the detector in real world situations declines. The infrared (IR) absorption spectrum of a material is a physical constant and highly specific for the molecule of interest. For many years, IR spectra have been used by chemists to identify unknowns based on comparison with spectra of known materials and to determine the presence of chemical functional groups through spectral interpretation. IR spectroscopy is well suited for the identification of broad-based chemical threats. This discussion shall concern the conceptual development of a hand held IR spectroscopy system for the identification of chemical vapor threats. The discussion shall focus on design tradeoffs where miniaturization is of paramount importance. Quantitative IR absorption spectra of threat compounds were used to model absorption line strengths at moderate spectral resolutions. IDLH detection limits targets, acquisition time, etendue, and signal-to-noise parameters guided the concept design and pathlength of a long path gas cell used in conjunction with a hand held FT-IR spectrometer.
Databáze: OpenAIRE