Fully Integrated Low-Cost High-Precision Carbon Dioxide Analyzer

Understanding global warming requires continuous field measurements of carbon dioxide concentrations. High-precision measurements of a part-in-3000, or better, are required. However, these high-performance instruments must meet stringent cost objectives. A simple, rugged, infrared spectrometer can provide the required measurement precision at the solicited volume price point. Vista Photonics proposes to develop a laser diode based spectrometer that can determine carbon dioxide concentration to 0.1 ppm precision in less than one minute with a retail price at $5,000. A new, simple and compact optical wavelength modulated carbon dioxide sensor was developed in this project. The Phase I work provides a solid foundation for the development of compact and rugged prototypes with 0.1 ppm measurement precision for long-term unattended field deployment. Integrated laser diode (LD) wavelength modulation spectrometer (WMS) prototypes will be designed and constructed. Long-term precision of the LD-WMS instruments for carbon dioxide will be determined. The low-cost sensor version will measure dry or wet ambient air with no sample preparation. The requirements for calibration and measurement procedures will be determined for long-term field deployment.Commercial Applications and Other Benefits: The proposed technology offers high-performance in an inexpensive, field-compatible, package. The spectrometer can meet DOEs low solicited price point, which sets it apart from existing devices of comparable performance. The approach will offer a compelling blend of price, performance and physical advantages in a variety of gas detection applications. Examples include atmospheric monitoring, environmental regulatory compliance, process gas analysis, and biomedical breath diagnostics.