Abstract: To achieve measurements of the atmospheric particle concentration, we design an impact-type clas-sified device based on the traditional impact of sampling theory and calibrated exactly. The extinct principle is used to particle samples which had been classified, and enhances the sensitivity of the measurement device by using re-flectors to increase the optical path. Finally, we realize the exact measurement of the grain concentrations of three particle ranges： 0～5μm,5～20μm and 15～40μm in the atmosphere.

Key words: grain concentrations, impact-type classify, calibrate, extinct principle