A methodology for the measurement of distributed agricultural sources of ammonia outdoors—Part 1: validation in a controlled environment

Autor: Welch, Denise C.1 denise.welch@bbsrc.ac.uk, Colls, Jeremy J.2, Demmers, Theo G.M.1, Wathes, Christopher M.1
Předmět:
Zdroj: Atmospheric Environment. Feb2005, Vol. 39 Issue 4, p663-672. 10p.
Abstrakt: Abstract: A flux frame method using recurved passive ammonia flux (PAF) samplers for the measurement of distributed outdoor agricultural sources of ammonia (NH3) was evaluated in a controlled environment. The collection efficiency of the samplers was determined in a wind tunnel at controlled values of NH3 flux density (0.77–13.5mg NH3m-2s-1), and over a range of angles of orientation to the flow direction (0°, 30°, 60°, 70°, 80° and 90°). The samplers were effective up to a wind speed of 7ms-1 and an angle of 80° with a mean collection efficiency of 71%. The flux frame method had a mean collection efficiency of 87.4% when used with ground level point sources under controlled conditions in an open-circuit wind tunnel with boundary layer airflow characteristics. [Copyright &y& Elsevier]
Databáze: GreenFILE
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