Sampling Method of Radionuclides in the Atmosphere

The technique for collecting radionuclides is to use an air sampler fitted with a filter that is connected to an air pump to collect radionuclide samples. The typical flow rate through an air filter using a 1 hp pump is about 1 m min~ . A pressure gauge is usually installed

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Figure 2 Model-calculated global distributions of yearly mean total deposition (Bq m^yr-1) of 210Pb for the year 2002. From Lee HN, Wan G, Zheng X, et al. (2004) Measurements of 210Pb and 7Be in China and their analysis accompanied with global model calculations of 210Pb. Journal of Geophysical Research (Atmospheres) 109: D22203 (doi: 10.1029/2004JD005061).

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Figure 2 Model-calculated global distributions of yearly mean total deposition (Bq m^yr-1) of 210Pb for the year 2002. From Lee HN, Wan G, Zheng X, et al. (2004) Measurements of 210Pb and 7Be in China and their analysis accompanied with global model calculations of 210Pb. Journal of Geophysical Research (Atmospheres) 109: D22203 (doi: 10.1029/2004JD005061).

in the air sampler for measuring air flow as a function of air pressure drop across the filter. The filter is changed daily or weekly depending on the radioactivity levels in the atmosphere. Typically the filter is made of a 20.3 x 25.4cm rectangle with an effective exposure area of about 407 cm and is composed of three layers of 100% polypropylene fibers. Increasing the flow rate of the sampler is the easiest way to increase the sensitivity for isotopes with short half-lives or low fission yields. The filter samples collected are then brought back to laboratory for counting and analysis.

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