Low Flow Rate Sharp Cut Impactors for Indoor Air Sampling: Design and Calibration

摘要: Two single round nozzle impactors have been developed for use in Harvard’s indoor air pollution health study. Both operate at flow rates of 4 L/m and are nearly identical, differing only their cut sizes 2.5 μm 10 aerodynamic diameters. identical cascaded stages the same size used to obtain sharp cut-off characteristics. The particles deposited on impaction plates made oil impregnated, porous material reduce particle bounce discarded. Only collected afterfilter analyzed. Special care has taken collect uniformly aid analysis. jmpactors were calibrated with a vibrating orifice monodisperse aerosol generator. However, due impactors, doublets triplets calibration aerosols, even small quantities, gave erroneous curves. Therefore, number challenging aerosols measured appropriate c...