A new two-stage respirable dust sampler

The design and laboratory evaluation of a new two-stage aerosol sampler is described. The first stage of the sampler employs an integral flat plat impactor to remove particles greater than 10 micrometers; particles that penetrate the impactor are collected on a 37 mm membrane filter with 5-micrometer pore size. The theoretical design parameters and experimental calibration data developed for the impactor sampling heads at flowrates of 2.0 and 3.0 liter per minute are presented, and their collection characteristics compared to those of present two-stage respirable dust samplers. The advantages and disadvantages of the two-stage impactor sampler are discussed.