Apparatus for Sampling and Controlling Gas Composition in Redox-Controlled Soil Slurry
- W. D. Guenzi ,
- G. L. Hutchinson and
- W. E. Beard
Study of the production or consumption in soil of gaseous N compounds at near ambient concentrations requires unique apparatus and procedures. We used a soil slurry that is continuously flushed by a gas stream with controlled composition. Basic components of the system include a reaction chamber equipped to monitor and control slurry pH, Eh, and temperature, flow controllers for precise control of gas flow rates, a mixing chamber for blending inlet gases from different sources, a low-volume manifold for collecting contamination-free samples of inlet and exit gases, a dryer to selectively remove water vapor from the exit gases, and a large-volume sample loop for collecting enough sample gas for NO analysis. The Eh control was accomplished using automated three-way solenoid valves to select either O2 or an equal flow of inert gas to mix with the gas stream flushing the reaction chamber. Although the gas sampling and gas handling apparatus and procedures described here were designed for an Eh-controlled soil slurry, we believe they could be easily adapted to other experimental systems that require trace gas sampling and control without contamination from ambient air.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .