基于米氏(Mie)散射理论得到了粒子计数器测量球形颗粒物质量密度的计算公式。考虑非球形颗粒,从颗粒群粒度分布概念出发,提出了统计意义上的平均质量概念,推导了非球形颗粒物质量密度的理论公式。运用理论公式证明了粒子计数器测量非球形颗粒物质量密度计算公式的合理性,进而给出了基于平均质量的悬浮颗粒物的质量密度算法,该算法只需对两个系数进行标定。实验表明,该算法的质量密度计算值与实际值十分吻合,两者拟合直线的斜率为0.9713,相关系数为0.9998。该算法为实现粒子计数器在线测量悬浮颗粒物的质量密度提供了一种可行途径。

Based on Mie scattering theory, the formula for calculating mass concentration of spherical particles by optical particle counter was established. Considering non-spherical particles, starting from particles size distribution, the concept of the average mass was put forward, and the theoretical formula for calculating mass density of non-spherical particles was derived. Using this theoretical formula, the rationality of the calculation formula of optical particle counter for non-spherical particles was verified. The aerosol mass density algorithm based on average mass was proposed, and only two coefficients need to be calibrated in the algorithm. The experimental results agree well with the mass density values calculated by the algorithm, the slope of fitting line is 0.9713 and the correlation coefficient is 0.9998. This algorithm offers a feasible way for the optical particle counter to measure aerosol mass density in real time.