科研之友
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摘要
The detection and quantification of biological particles in the atmosphere is becoming an increasingly important field of study. One instrument designed for this purpose, known as WIBS-4, can measure individual particles and their number-size distributions in two pre-defined size ranges: (i) similar to 0.3-12 mu m and (ii) similar to 3-31 mu m (optical diameter, polystyrene latex equivalent) while also making measurements of fluorescence across two wavebands. It can also supply simultaneous information on particle asymmetry. %26lt;br%26gt;Since particle number concentrations are provided by the technique, the counting efficiency of WIBS-4 needs to be defined. Therefore in the current study, a method for calibration suitable and necessary for use with single particle measuring instruments is described. The lower-end counting efficiency curve for the WIBS-4 was thereby defined in specific size regimes for the first time (D-50 similar to 0.489 mu m and D-100 similar to 0.69 mu m). Experiments were conducted at room temperature and atmospheric pressure using a range of different sized PolyStyrene Latex (PSL) microspheres. A TSI 3010 condensation particle counter, using butanol as a working fluid, was used as a reference particle counter. The results also demonstrated a relationship between fluorescence intensity and the calculated volume of the PSL particles, when lambda(ex) =280 nm and lambda(em) similar to 310-400 nm. To our knowledge the current study represents the first to provide the fluorescence particle sensor community with both the counting efficiency of the WIBS-4 and a relationship plot giving a fluorescence intensity-particle size correlation over a broad PSL size range.
- 出版日期2012-5
