Laser-based Sensor for routine, High Precision, Field Measurements of Ambient CO2

Trace species such as carbon dioxide, carbon monoxide, and methane are important in the carbon cycle of the atmosphere and in global climate change. Highly precise measurements of these species are important to carbon cycle studies and global warming research. New, compact, low maintenance, and low cost instrumentation is required to make measurements of these trace gases with high specificity and sensitivity in national and international monitoring networks. This project will design and demonstrate a new sensor for high precision measurement of ambient CO2. The sensor will combine advances in diode laser technology with cavity enhanced absorption methods, resulting in a measurement precision on the order of 1 in 3000. The cost will be low enough to allow wide deployment in atmospheric monitoring networks. During Phase I, a prototype laboratory sensor was created by coupling a tunable diode laser to a high finesse optical cavity, and the required measurement precision for ambient monitoring of CO2 was demonstrated. A complete conceptual design for a compact lightweight sensor, which is particularly well suited for network monitoring, was developed. A production cost model indicated that the sensor design can meet the target acquisition price of $5000 per copy when produced in volume. In Phase II, an alpha prototype sensor will be fabricated. Extensive characterization of the sensor¿s performance, as well as in-house environmental testing, will be carried out. The sensor will be demonstrated in the field at several venues. By the end of the Phase II, a complete design for a beta-prototype will be developed. Commercial Applications and other Benefits as described by the awardee: A new, high precision, economical sensor for ambient CO2 measurements should fulfill a long-standing need for a precise instrument that is rugged enough for field use and economical enough for widespread application in monitoring networks. Applications include environmental and air quality monitoring, combustion emissions analysis, fugitive emissions control, industrial process control, and contraband detection