The aerosol transmission efficiency of the 10 m sampling inlet at the Cape Grim Baseline Air Pollution Station (CGBAPS) has been modelled using finite volume techniques (CFX software). We examined particles in the range 1-20 mum aerodynamic diameter with a range of wind speeds and angle of attack values. Computed average transmission efficiencies were close to 100% for the smaller particles in this range but fall below 25% above about 20 mum. When the incident flow is at small inclined angles, some enhancement or depletion is observed relative to the mean horizontal particle concentration flow. (C) 2003 Elsevier Ltd. All rights reserved.