New experimental studies of the basic performance characteristics of aerosol samplers.

The study of the basic physical performance characteristics of aerosol samplers, like those used in the occupational hygiene setting, will provide insights to enable the improved development of new instruments and cost-effective testing procedures. These will be required as the new particle size-selective sampling criteria become the basis of new occupational exposure standards. A new body of work is being conducted, in which the factors influencing sampler performance are being investigated using idealized samplers of spherical shape in small wind tunnels. By the experimental methods described, a large amount of performance data can be acquired in a very short time. The results for wide ranges of particle size, wind speed, sampling flow rate, and sampler orientation conditions show that there are strong trends as functions of these variables. Those trends are very complicated. But it is encouraging that they are broadly consistent with recent semi-empirical models, suggesting that extensions of that type of modelling approach--supported by the large amount of new experimental data now being generated by such experiments--might provide new models of aerosol sampler performance accessible to researchers and occupational hygienists.