Thursday, February 8, 2007

A Comparative Analysis of Instruments Commonly Employed to Measure Greenhouse Gas Emissions From Soils.

Jason B. Bartlett, Amy King, Dianne Louie, and Dennis Rolston. University of California, Davis, Department of Land, Air, and Water Resources, One Shields Avenue, Davis, CA 95616

As global warming becomes a more important issue on the world stage, analyzing greenhouse gases (GHGs) with consistency and accuracy across agencies and ecosystems becomes paramount. This study compared the performance of 4 commonly used instruments to measure CO2 and N2O emissions from surface soils in closed chamber systems. A photoacoustic multi-gas monitor, an infrared gas analyzer, a gas chromatograph and a small stationary infrared gas analyzer were all analyzed for their accuracy, range, consistency, cost and convenience of use in the field. Each instrument was compared with the others to determine how similarly they measured known standards. It was determined that the lower cost instruments perform with acceptable levels of consistency and accuracy as higher cost instruments. Advantages and disadvantages of each system for use in the lab and in the field are discussed.