Cavity-Absorption Techniques for the Use in a Tunable Diode Laser Sensor for Monitoring Spacecraft Air Quality The George Washington Univ

Format:

Conference/Event

Author/Creator:

Awtry, A. R., author.

Conference Name:

31st International Conference On Environmental Systems (2001-07-09 : Orlando, Florida, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2001

Summary:

The progress on the development of a sensor for monitoring spacecraft air quality is reported. A 1.55 μm external-cavity tunable diode laser is used as a light source that can be incorporated in either cw-Integrated Cavity Output Spectroscopy (cw-ICOS) or cw-Cavity Ringdown Spectroscopy (cw-CRDS). Both techniques exploit the sensitivity enhancements provided by the long effective pathlength from the optical cavity created between two mirrors. Initial experiments of cw-ICOS have been performed to determine the sensitivity, selectivity, and reproducibility of this method. Passing the laser beam through a flame supported on an atomic absorption burner produced a dense spectrum of absorption lines in the 15451560 nm region. While most of the absorbance peaks observed in the flame were assigned to water, a number of spectral features have been assigned to the OH radical. Using an estimate of the OH concentration in this flame, the detection limit for OH in this system was determined to be 60 ppm. In the continuing work, the sensitivity of cw-CRDS will be compared with cw-ICOS to determine which method holds greater promise for a practical sensor

Notes:

Vendor supplied data

Publisher Number:

2001-01-2198

Access Restriction:

Restricted for use by site license