Field tests have been conducted to evaluate the passive aerosol sampler described by Wagner and Leith (2000a,b) Aerosol Science Technology, in press). Tests were conducted in a well-ventilated occupational environment with coarse, high-concentration aerosols. Measured friction velocities were less than 0.4 m s(-1) a range in which passive sampler performance does not depend on turbulence. Passive sampler results correlated well with those of eight-stage cascade impactors, with R-2 = 0.80 and 0.93 for PM2.5 and PM10, respectively. Average disagreement between the passive samplers and the impactors was -31 and 41% for PM2.5 and PM10, respectively. These discrepancies were attributed to the small amount of fine particles present, hygroscopic particles, and particle bounce in the impactors. The average CVPM10 for all samples was 20%. The average CVPM2.5 for non-hygroscopic samples was 16%. The average CVPM2.5 for hygroscopic samples was much higher, 59%; water losses in these samples created ill-defined particle boundaries which led to imprecision. (C) 2000 Elsevier Science Ltd. All rights reserved.