RESPIRABLE AEROSOL SAMPLER PERFORMANCE TESTING

Performance tests for evaluating respirable aerosol sampling methods w ere developed. The tests entail measurement of the flow-dependent coll ection efficiency of the aerosol size-discriminating part of the sampl er using an aerodynamic particle sizer. The bias relative to an intern ational sampler standard adopted by the American Conference of Governm ental Industrial Hygienists, the International Standards Organization, and the Comite Ercropeen de Normalisation is mapped over aerosol size distributions of intended application. Imprecision from flow-effects, filter weighing errors, and intersampler variability is either measure d or estimated Uncertainty in the evaluation experiment itself is expl ained. Samplers can be rejected if, at specified confidence in the eva luation testing, accuracy is lacking in too large a fraction of sample s. Alternatively, the data permit specifying a value of the inaccuracy . Two commercially available personal samplers were subjected to the p erformance tests suggested. The result was the specification of the fl owrates at which the samplers closely match the international definiti on. Furthermore, upper limits on die inaccuracy at which a sampler can be expected to operate were determined. The effect of the acceptance of such performance criteria rather than sampler design specification for compliance sampling would be to encourage the use of accurate samp lers and, thus, the development of improved samplers.