Fig. 1. The Lubbock Dust Generation, Analyses and Sampling System (LDGASS) that contains (A) a dust-generating tube, (B) two valves, (C) U tubing, (D) a settling chamber, and (E) two dust filters and an air flow meter to control attached vacuum. The 27- and 7-µm dust samples were collected in (C) and (D), respectively.