Aerosol sampling by an annular slot sampler with a smooth aspiration tube entrance

The sampling of coarse aerosols by the annular slot sampler with a smooth aspiration tube entrance was studied. The values of the outer aspiration coefficient and the particle penetration through the sampler were measured for different flow conditions. The dependences of these parameters were investigated on the sampler geometry and on the aspiration regime. The data obtained were compared with those of other authors. A set of dimensionless criteria is proposed for the modelling of aspiration in the annular slot sampler. It is demonstrated that the application of the annular slot sampler for sampling of atmospheric aerosols requires correction by the aspiration efficiency.