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 |
顯示於類別: | 期刊論文 |