Price-Protected High-Precision Carbon Dioxide Analyzer

Understanding global warming requires continuous field measurements of carbon dioxide concentrations. High-precision measurements of 1 part in 3000 or better are required. However, these high-performance instruments must meet stringent cost objectives. A simple, rugged, photoacoustic spectrometer can provide the required measurement precision at the solicited volume price point. This project will develop a laser-diode-based spectrometer that can determine carbon dioxide concentration to 0.1 ppm precision in under one minute with a retail price at $5,000. In Phase I, a bench top laser diode (LD) photoacoustic spectrometer (PAS) will be constructed as a proof-of-principle device. The sensitivity and selectivity of the LD-PAS instrument for carbon dioxide will be determined using two types of laser diodes. The least expensive sensor version will measure dry ambient air, while the higher value system will measure both CO2 and water vapor. Requirements for calibration and measurement procedures will be determined for long-term field deployment. Commercial Applications and other Benefits as described by the awardee: The technology should provide high-performance in an inexpensive, field-compatible, package for a variety of gas detection applications, including atmospheric monitoring, environmental regulatory compliance, process gas analysis, and biomedical breath diagnostics.