A study evaluated differences between respirable dust concentrations measured with three currently available cyclone samplers in a field setting. Comparisons also were made between cyclone and personal cascade impactor results. The cyclones selected were designed for sampling according to one of three respirable dust criteria: British Medical Research Council (BMRC) (D50=5 µm), previous American Conference of Governmental Industrial Hygienists (ACGIH) (D50=3.5 µm), and proposed ACGIH (D50=4 µm). Samples were collected by placing two each of three brands of cyclone, two personal cascade impactors, and two total dust samplers on a tripod-mounted boom assembly. The apparatus sampled abrasive blasting operations. A significant difference was detected between the results of the BMRC and proposed ACGIH-type samplers and between the BMRC and previous ACGIH-type samplers. The BMRC-type sampler consistently yielded the highest average respirable dust concentrations, followed by the proposed ACGIH and previous ACGI...