標題: The performance of the PM2.5 VSCC and oil-wetted M-WINS in long-term field sampling studies
作者: Thi-Cuc Le
Fu, Chang-Xing
Sung, Jung-Che
Li, Zi-Yi
Pui, David Y. H.
Tsai, Chuen-Jinn
環境工程研究所
Institute of Environmental Engineering
關鍵字: PM2.5;Impactor;Sampling inlet;M-WINS;VSCC
公開日期: 15-十月-2020
摘要: Most of PM2.5 FRM samplers and FEM monitors use a well impactor ninety-six (WINS) or very sharp cut cyclone (VSCC) to classify particles smaller than 2.5 mu m in diameter. However, the WINS has the particle loading effect and needs to be cleaned after 3 to 5 sampling days. The VSCC was claimed not to be affected by the particle loading effect in a laboratory study but without the support of field studies. In this field comparison study using daily cleaned VSCC as the reference, the uncleaned VSCC showed overall good performance in three long-term testing periods: period #1 (21 days), period #2 (124 days), and period #3 (30 days). However the fluctuation in PM2.5 concentrations of the uncleaned VSCC occurred in day 14 (D14) and D16 of period #1 due to particle bounce and re-entrainment effects; and also in D19, D31 and D44 of period #2, and in D28 and D29 of period #3 due to particle loading effect. After the sampling periods longer than 21 days in period #2 and #3, the particle loading effect resulted in persistently lower PM2.5 concentrations due to smaller cut-sizes and smoother penetration curves. In comparison, the oil-wetted M-WINS designed by our group showed a better performance with less than +/- 5% bias and +/- 2 mu g m(-3) concentration difference during two long-term tests: periods #2 and #3. This study proved once again that the M-WINS is a viable PM2.5 sampling inlet that meets the long-term PM2.5 sampling or monitoring need.
URI: http://dx.doi.org/10.1016/j.atmosenv.2020.117804
http://hdl.handle.net/11536/155322
ISSN: 1352-2310
DOI: 10.1016/j.atmosenv.2020.117804
期刊: ATMOSPHERIC ENVIRONMENT
Volume: 239
起始頁: 0
結束頁: 0
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