Abstract
In order to prevent atmospheric particulate matter around the main roadside and large parking area, a repeated impaction facility without an increase of pressure drop was developed. Collection efficiency was amplified up to 81％ when 50 impaction stages were used. Observation using an electron microscope suggests the collection of not only coarse particles but also partially fine particles. According to the result of the chamber experiment conducted separately, the increase in the number of impaction stages is expected in the promotion of the collection efficiency in the future.
