title: Development of a cw-laser-based cavity-ringdown sensor aboard a spacecraft for trace air constituents.
abstract: The progress in the development of a sensor for the detection of trace air constituents to monitor spacecraft air quality is reported. A continuous-wave (cw), external-cavity tunable diode laser centered at 1.55 micrometers is used to pump an optical cavity absorption cell in cw-cavity ringdown spectroscopy (cw-CRDS). Preliminary results are presented that demonstrate the sensitivity, selectivity and reproducibility of this method. Detection limits of 2.0 ppm for CO, 2.5 ppm for CO2, 1.8 ppm for H2O, 19.4 ppb for NH3, 7.9 ppb for HCN and 4.0 ppb for C2H2 are calculated.
authors.affiliation: The George Washington University, Washington, DC 20052, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Awtry
authors.forename: J H
authors.initials: JH
authors.lastname: Miller
mesh_terms: D000114:Acetylene / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D000641:Ammonia / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D004784:Environmental Monitoring / Q000295:instrumentation*; D005069:Evaluation Studies as Topic; D006856:Hydrogen Cyanide / Q000032:analysis; D007834:Lasers; D008452:Maximum Allowable Concentration; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018531:Spacecraft / Q000295:instrumentation* / Q000592:standards; D013057:Spectrum Analysis / Q000295:instrumentation; D014867:Water / Q000032:analysis
chemical_list: D000393:Air Pollutants; D014867:Water; D002245:Carbon Dioxide; D006856:Hydrogen Cyanide; D000641:Ammonia; D002248:Carbon Monoxide; D000114:Acetylene