针对目前尚无有效测量建筑工地等无组织排放源排放的颗粒物质量浓度的方法的问题,提出基于后向光散射的无组织排放颗粒物质量浓度远程测量方法,其测量结果为柱形光束段的颗粒物质量浓度平均值。建立后向散射光能与颗粒物质量浓度、测量距离的理论模型,搭建以半导体激光器为光源和以互补金属氧化物半导体(CMOS)图像传感器为探测器的便携式测量装置,开发了图像处理程序。通过标定实验验证了颗粒物质量浓度与系统输出值之间的线性关系,并得到了标定曲线。实验分析了较大颗粒的粒径及测量距离在100 m以内的变化对测量结果的影响。同时选取无组织排放源进行现场模拟测试。结果表明:基于新方法的实验测量装置可应用于开放场地无组织排放气团中颗粒物柱浓度的远程估测。

A remote measurement method for the mass concentration of fugitive-dust-emission particulate based on backward light scattering is proposed to overcome the problem that there is no effective measurement method for the mass concentration of particulates from open and fugitive-dust-emission sources such as construction sites. The measurement result of the proposed method is the average mass concentration of particulates of the cylindrical beam segment. The established theoretical model takes into account the backscattered light energy, mass concentration of particulates, and measuring distance. A portable measuring device is developed using a semiconductor laser as a light source and complementary metal oxide semiconductor image sensor as a detector, as well as an image processing program. The linear relationship between the mass concentration of particulates and output value of the system is verified by calibration experiments, which renders the calibration curve. Effects of large particle size and measuring distance changing within 100 m on the measurement results are compared and analyzed. At the same time, the fugitive emission source is selected for actual measurement. The results show that the experimental measurement device based on the new method can be applied to the remote estimation of the mass concentration of particulates in the fugitive emission air mass in the open field.