NASA 1996 SBIR Phase I

PROJECT TITLE : Compact Optical Trace Gas Flux Sensor (7117-150)

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

Physical Sciences Inc. (PSI) proposes to develop an optical flux sensor, based on a room temperature, mid-ir tunable diode laser absorption spectro- meter, capable of directly measuring fluxes of several important biogenic species, including CO2, CH4, and H2O, via eddy correlation. The innovation of our sensor is a novel, noise-cancelling detection technique that enables ultrasensitive absorption measurements without recourse to frequency modula- tion (FM) detection. Our technique affords high sensitivity, precision, and fast temporal response. The sensor will use an open, optical multipass cell for in situ sampling, thereby bypassing the concerns of extractive sampling. These innovations will result in a sensor well suited for routine, extended field deployment and capable of making direct flux measurements of several biogenic trace gases. These measurements will support airborne in situ and remote sensing measurements of the relationships between the atmosphere and the biosphere, especially of the exchange of biogenic trace gases between the surface and the atmosphere.

The proposed program will result in a design for a multigas flux sensor for monitoring of CO2, CH4, and H2O. A high sensitivity CH4 field sensor will have commercial applications as a fenceline monitor for fugitive emissions from natural gas pipelines and processing facilities and from chemical manufacturing plants. A high sensitivity CO2 field sensor will find commer- cial application in monitoring and validation of the performance of combustion systems in industrial and utility environments.

David M. Sonnenfroh
Physical Sciences Inc.
20 New England Business Center
Andover, MA 01810-1077

Physical Sciences Inc.
20 New England Business Center
Andover, MA 01810-1077