Characterization of the 8-stage Rotating Drum Impactor under low concentration conditions

PM2.5 measurements from IMPROVE samplers were in better agreement with integrated size-resolved measurements made by MOUDI samplers than RDI samplers in the summer season, however with higher concentrations in the winter season both instruments performed with similar accuracy when using the XRF analysis method. MOUDI samples analyzed by ICP-MS had the best agreement overall with IMPROVE samples analyzed by ICP-MS. These results suggest that MDLs should be reassessed for all methods and a longer collection time should be considered under low concentration conditions.