Cavity Attenuation Phase Shift Spectroscopic Detection of Nitrogen Dioxide

72080S03-I Nitrogen dioxide emissions are regulated by a national ambient air quality standard under the 1970 Clean Air Act. The prevalent means of detection, a chemiluminescence-based monitor (the so-called NOx box), often provides inaccurate readings for nitrogen dioxide in the presence of other nitrogen-containing trace atmospheric species. This project will build an uncomplicated, inexpensive, and accurate spectroscopic sensor for the detection of nitrogen dioxide at the sub part-per-billion level using Cavity Attenuation Phase Shift spectroscopy, a technique related to cavity ringdown laser absorption spectroscopy. It relies on the measurement of small shifts in the phase of modulated light that is transmitted through a resonant optical cavity induced by the absorption of the target species. Phase I will involve a proof-of principle demonstration using commercially available instrumentation. Commercial Applications and Other Benefits as described by awardee: Compact, inexpensive and accurate nitrogen dioxide point sensors, suitable as tools for the measurement of urban pollution, will be needed as concerns about atmospheric pollution increase. Markets for this instrument should include the atmospheric research community, and entities that provide routine monitoring of exhaust from gas turbines, chemical plants, and refineries.