標題: The Influence of Relative Humidity on Nanoparticle Concentration and Particle Mass Distribution Measurements by the MOUDI
作者: Chen, Sheng-Chieh
Tsai, Chuen-Jinn
Chen, Hong-Dar
Huang, Cheng-Yu
Roam, Gwo-Dong
環境工程研究所
Institute of Environmental Engineering
公開日期: 2011
摘要: A humidity control system was operated upstream of two collocated-MOUDIs (micro-orifice uniform deposit impactors) for sampling ambient aerosol particles. One MOUDI used silicone-grease-coated aluminum foils (ALs) as the impaction substrates and was considered as the reference impactor, while the other used uncoated ALs or uncoated Teflon filters (TFs) as the impaction substrates for quantifying the effect of different relative humidities (RHs) and impaction substrates on the PM(0.1) concentrations and mass distributions of ambient PMs. Test results showed that decreasing RH in general increased particle bounce from uncoated substrates with the bounce from uncoated ALs being more severe than that from uncoated TFs. Particle bounce did not influence the overall mass distribution of ambient fine particles when RH ranged between 40% and 80%, whereas it led to undersampling of particles greater than 2.5 mu m in aerodynamic diameter severely. Oversampling of PM(0.1) occurred by as much as 95%-180% or 25%-55% when the MOUDI used uncoated ALs or TFs, respectively, as RH was reduced from 50% to 25%. Particle bounce was found to be negligible, and PM(0.1) and PM(2.5) could be sampled accurately with less than 5% error at the RH of 75%-80% or 65%-80% when uncoated ALs or TFs were used, respectively.
URI: http://hdl.handle.net/11536/26074
http://dx.doi.org/10.1080/02786826.2010.551557
ISSN: 0278-6826
DOI: 10.1080/02786826.2010.551557
期刊: AEROSOL SCIENCE AND TECHNOLOGY
Volume: 45
Issue: 5
起始頁: 596
結束頁: 603
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