基于光闪烁的颗粒物浓度测量技术已成为工业现场非介入式测量的重要手段.为研究工业烟道内烟尘粒子谱分布和粒径对探测光束强度的影响，以朗伯-比尔定律为基础，结合粉尘消光系数与烟尘种类、中位粒径等关系，模拟计算了烟尘粒子粒径满足对数正态和高斯两种分布状态下探测光强的衰减情况.从计算结果看: 满足对数正态分布的烟尘粒子对光束衰减更明显，且粒径越小衰减效果越明显.

Optical method for measurement of particulate concentration in flue basing on optical scintillation is an important non-intrusive technology. In order to research the influence of particles to optical intensity，the inten- sity degradation of probing beam is simulated basing on Lambert-Beer's law，when particle size distribution satisfies logarithm normal distribution and Gauss distribution，respectively. In the calculation，the relationship between ex- tinction coefficient and species and the middle level diameters are pre-calculated. The results show that，when the particle size distribution satisfies logarithm normal distribution，the intensity degradation of probing beam is more significantly. The optical intensity exhibites the same changes when the particle size decreases gradually.