光学学报, 2020, 40 (6): 0629001, 网络出版: 2020-03-06
小流量高浓度颗粒物光学计数及重叠校正方法研究 下载: 1055次
Study of Optical Counting and Coincidence Correction Method for Particle with Small Flow and High Concentration
散射 粒子光散射 光学粒子计数 单粒子回波脉冲 粒子重叠 scattering particle light scattering optical particle counting echo pulse of single particle particle coincidence
摘要
传统的光学粒子计数方法受到粒子回波脉冲带宽限制,难以直接应用于超细颗粒物凝结增长后端的颗粒物数量检测。基于粒子光散射原理,采用高带宽粒子回波脉冲方案设计了颗粒物光学计数模块,在0.3 L·min -1采样流量下,15 μm标准聚苯乙烯颗粒回波脉冲半宽为650 ns,粒子计数效率得到有效提高。为了提高颗粒数浓度测量上限与精度,基于概率统计提出了粒子重叠校正方法,利用此方法颗粒物数浓度测量上限可达2×10 5 cm -3。在自制的正丁醇超细颗粒物凝结增长装置中开展了对比实验。结果表明,该系统与环境空气数浓度测量设备TSI-3788和Airmous-A20的相关性均超过0.98,与机动车尾气固态颗粒物数浓度法规测量设备MEXA-200SPCS的相关性高达0.96,从而验证了所设计的颗粒物光学计数模块及重叠校正方法的准确性。
Abstract
The traditional optical particle counting method is limited by the bandwidth of particle echo pulse. Therefore, it cannot be directly applied to the measurement of particle number at the back end of the ultrafine particle condensation growth system. In this paper, based on the principle of particle light scattering, a particle optical counting module by using the scheme of high-bandwidth particle echo pulse is designed. At a sampling flow rate of 0.3 L·min -1, the echo pulse half-width of the 15 μm standard polystyrene particle is 650 ns, which improves the efficiency of particle counting. In order to improve the upper limit and accuracy of the particle number concentration measurement, a particle coincidence correction method based on probability statistics is proposed. The upper limit of the particle number concentration measurement is 2×10 5 cm -3 by using this correction method. Experiments in the self-developed butanol-based ultrafine particle condensation growth system are conducted. The results show that the correlations between the self-developed system and the ambient air concentration measurement devices TSI-3788 and Airmous-A20 both exceed 0.98 , and in contrast, that between the self-developed system and the vehicle emission solid particle number concentration measurement device MEXA-200SPCS is up to 0.96. Thus, the accuracies of the designed optical particle counting module and the coincidence correction method are verified.
王文誉, 刘建国, 赵欣, 张礁石, 余同柱, 桂华侨, 杨义新. 小流量高浓度颗粒物光学计数及重叠校正方法研究[J]. 光学学报, 2020, 40(6): 0629001. Wenyu Wang, Jianguo Liu, Xin Zhao, Jiaoshi Zhang, Tongzhu Yu, Huaqiao Gui, Yixin Yang. Study of Optical Counting and Coincidence Correction Method for Particle with Small Flow and High Concentration[J]. Acta Optica Sinica, 2020, 40(6): 0629001.