A MULTI-STAGE IMPACTOR SAMPLER FOR AIR-BORNE PARTICULATES
大气飘尘冲击式分级采样器

In this paper, the principle of the multi-stage impactor sampler was discribed and collection probability by means of a distribution function was defined. It must be pointed out that a multi-stage sampler can well be studied just like a single-stage one if the concept of relative collection probability is introduced. Through analysis of the characteristic curves of the samplers, this paper indicates that there are restraints between the main size range of collected particles and the absolute collection probability. Finally, performance calculation and optimum design of the sampler are given. An appraisal has been done for the LH-1 type sampler designed by using this method, expected performance has been met with success.