为了研究激光尘埃粒子计数器计数信号幅度概率分布,对激光尘埃粒子计数器计数信号幅度概率分布与传感器光敏区光强分布、采样气流中的粒子数密度、气体层流速度分布之间的关系进行了理论分析。采用自行设计的带保护气套的光电传感器测定粒子计数信号幅度概率分布,给出的分布模型与理论分析相吻合。结果表明,尘埃粒子计数器计数信号幅度概率分布由传感器光敏区光强分布和粒子数密度空间分布共同决定,这为尘埃粒子计数器的设计提供了理论依据。

In order to study the probability distribution of counting signal amplitude in a laser airborne particle counter,the relationship between the probability distribution of counting signal amplitude,particles number density in the sampling air-flow,light-intensity uniformity of the sensitive volume and the speed distribution of the lamellar flow were theoretically analyzed.Then,the probability density distribution of the counting signal amplitudes was tested with a self-designed optical sensor with sheath-air inlet,and it matched well with the theoretical result.In a word,the results indicate that the probability distribution of counting signal amplitude is determined by both the intensity distribution of the sensitive volume and the space distribution of the particles number density,which proposes a theoretical basis for the design of the particle counter.