Interlaboratory evaluation of two inlets for sampling particles less than 10 mu m

An interlaboratory study of two PM sub(10) inlets by three independent laboratories was undertaken. Each laboratory tested the inlets in separate wind tunnels at 8 km/h with oleic acid particles and provided performance curves of sampling effectiveness vs. particle diameter. Data from two out of three laboratories indicated that the tested inlest would not meet EPA's proposed performance specification for cutpoint. Integration of the sampling effectiveness curves against an assumed aerosol size distribution indicated the inlets would meet the proposed specification for expected mass concentration regardless of which laboratory data are used. A new method of data analysis was devised to assess the observed differences among the laboratory performance curves. This study was the first attempt at an interlaboratory evaluation of PM sub(10) inlets, and although the test methods have not been standardized, the results are encouraging.