Fig. 7.

Button fractional collection efficiency defined as the concentration measured on each sampler component relative to the concentration measured by a sharp-edged isokinetic sampler as a function of particle size and type (solid particles versus droplets) at 0.4 m s⁻¹ wind speed. Black bars represent collection efficiency for solid particles by gravimetry (i.e. the sampling efficiency). Gray bars represent the collection efficiency of the filter (i.e. the sampling efficiency); white bars depict the collection efficiency of the sampler's screened inlet as determined by fluorescence analysis.