烟雾是火灾探测的重要参量，烟雾颗粒粒径及其尺度分布直接影响到感烟探测器的灵敏度，而目前有关烟雾颗粒粒径的研究相当匮乏。采用扫描迁移率粒子测量仪对火灾标准火烟雾颗粒的粒径大小及其分布进行实验测量，并采用数学拟合方法系统研究了烟雾颗粒粒径分布函数，研究结果表明对数正态分布函数较好地描述了烟雾颗粒尺度分布特征，其结论有益于火灾探测基础研究的发展。

Smoke is the important parameter of fire detection, and smoke particle size and its distribution may affect the sensitivity of smoke detectors directly. However, up to now there had no report about such research. In this paper, the theory, configuration and measurement method of Scanning Mobility Particle Sizer (SMPS) were described and the particle size and its distribution of four standard fire smoke were measured by SMPS. The particle size distribution function of smoke were studied by mathematic fitting methods, and the result of research showed that Logarithm Normal Distribution (LND) could represent the distribution of fire smoke particle size. The results may be benefit for the foundational research on fire smoke detection.