Performance of the Harwell-type size-selective dust sampler

Accuracy for measuring respirable dusts of the Harwell-type size-selective dust sampler has been studied by numerical analysis using the experimental data of calibration test. The test was made with uranine methylene-blue particles of uniform particle sizes (aerodynamic diameter dsub(a) = 1--17 μm, geometric standard deviation sigmasub(g) = 1.07--1.16) ; the sampler was examined at air flow-rate 6--50 l/min. Performance of the sampler at flow rate 33 l/min agrees with the lung deposition at a tidal volume of 750 cm3, and that at 50 l/min approximately with the lung deposition at tidal volume 1450 cm3. The performances is hardly influenced by variation of the flow rate less than 10%. The accuracy of this sampler for respirable dusts at flow rate 33 l/min is within a factor of 2 for MMAD <= 10 μm. (auth.)