Critical Analysis of Four Particle Sizing Samplers

A field study was conducted to compare performances of four particle sizing samplers including circular jet cascade impactor, rectangular jet cascade impactor (slotted), cyclonic jet cascade impactor, and dichotomous sampler. Sampling runs were performed with the samplers operating simultaneously in order to facilitate direct comparisons. Several problems were noted which hindered performance. Particle bounce was a definite cause for erroneous results in all impactors unless a greased impaction surface was used. Whenever particle bounce occurred, a significant amount of wall loss also occurred. In some cases the dichotomous sampler exhibited a high degree of wall loss due to its intricate internal piping. The small intake volumes of the cyclonic jet and dichotomous samplers during a 24-hour period necessitated a precise balance to measure the collected sample of ambient particulates. The circular jet cascade impactor, using silicone-greased aluminum foil collection medium, was found to be the only sampler of the four which performed consistently.