Price-Protected High-Precision Carbon Dioxide Analyzer

Understanding global warming requires continuous field measurements of carbon dioxide concentrations. High­ precision measurements (one part ­in­ 3000 or better) are required; yet, these high ­performance instruments must meet stringent cost objectives. A simple, rugged, photoacoustic spectrometer can provide the required measurement precision at the required volume price point. This project will develop a laser-diode-based spectrometer that can determine ambient carbon dioxide concentration to better than one part ­in ­3000 in less than one minute, while meeting a retail price of $5,000 under volume manufacturing. In Phase I, a bench-top laser diode (LD) photoacoustic spectrometer (PAS) was constructed for proof-­of­-principle testing. The excellent performance characteristics of the LD­PAS sensor ¿ including sensitivity, selectivity, and long term behavior ¿ were experimentally confirmed. In Phase II, (1) fully integrated LD­PAS sensor prototypes will be constructed for carbon dioxide field analysis; (2) standard operating protocols for the sensors will be established; and (3) the prototypes will be refined through beta ­testing in several field applications. Commercial Applications and other Benefits as described by the awardee: In addition to measurements of atmospheric carbon dioxide, the technology should enable general-purpose trace gas detection in a variety of applications, including biomedical breath diagnostics, process gas analysis, and environmental regulatory compliance.