【摘要】 利用自行开发的设计计算软件,完成了PM2.5切割器特性尺寸的精确设计及其切割性能对喷嘴尺寸、采样流量和环境因素的敏感性分析.铝质切割器的切割粒径为2.42μm,捕集的颗粒物质量浓度与"理想采样器"相差8.1%;采样系统的气密性良好,1min内压力下降小于0.005MPa;累积采样流量偏差小于±5%.实验室验证、与美国同类商业化采样器的平行采样对比以及在三个城市的现场运行均表明,研制的多通道PM2.5采样器的性能满足一次采样供质量浓度、化学物种及单颗粒特征等分析的实际应用需要.更多还原

【Abstract】 PM2.5 impactor is designed by using self-developed impactor-calculating software.Its particle separating performance influenced by nozzle sizes,flow-rate,and circumstance factors is also analyzed.The cut diameter of an aluminum impactor is 2.42 μm,and the mass of collected particles is with relative error of 8.1% to that expected for the ‘ideal sampler’.The sampling system is of good gas tightness with pressure drop of less than 0.005 MPa within 1 min and good flow stability with cumulative flow deviation of less than ±5%.The performance of the developed sampler meets the requirement of practical speciation sampling of ambient fine particles to be used for the measurement of mass,chemical species,and single particle characteristics simultaneously,which has been verified with laboratory test,parallel sampling comparison with a commercial sampler made in the USA,and field sampling in three typical cities in China.更多还原