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Qualification of a Multi-Channel Infrared Laser Absorption Spectrometer for Monitoring CO, HCl, HCN, HF, and CO2 Aboard Manned SpacecraftMonitoring of specific combustion products can provide early-warning detection of accidental fires aboard manned spacecraft and also identify the source and severity of combustion events. Furthermore, quantitative in situ measurements are important for gauging levels of exposure to hazardous gases, particularly on long-duration missions where analysis of returned samples becomes impractical. Absorption spectroscopy using tunable laser sources in the 2 to 5 micrometer wavelength range enables accurate, unambiguous detection of CO, HCl, HCN, HF, and CO2, which are produced in varying amounts through the heating of electrical components and packaging materials commonly used aboard spacecraft. Here, we report on calibration and testing of a five-channel laser absorption spectrometer designed to accurately monitor ambient gas-phase concentrations of these five compounds, with low-level detection limits based on the Spacecraft Maximum Allowable Concentrations. The instrument employs a two-pass absorption cell with a total optical pathlength of 50 cm and a dedicated infrared semiconductor laser source for each target gas. We present results from testing the five-channel sensor in the presence of trace concentrations of the target compounds that were introduced using both gas sources and oxidative pyrolysis (non-flaming combustion) of solid material mixtures.
Document ID
20170008204
Document Type
Conference Paper
External Source(s)
Authors
Briggs, Ryan M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Frez, Clifford (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Forouhar, Siamak (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
May, Randy D. (Port City Instruments Henderson, NV, United States)
Meyer, Marit E. (NASA Glenn Research Center Cleveland, OH, United States)
Kulis, Michael J. (NASA Glenn Research Center Cleveland, OH, United States)
Berger, Gordon M. (National Center for Space Exploration Research on Fluids and Combustion Cleveland, OH, United States)
Date Acquired
September 1, 2017
Publication Date
July 12, 2015
Subject Category
Man/System Technology and Life Support
Spacecraft Instrumentation and Astrionics
Report/Patent Number
ICES-2015-300
Meeting Information
International Conference on Environmental Systems(Bellevue, WA)
Distribution Limits
Public
Copyright
Other
Keywords
environmental monitoring