A detailed set of tests in a wind tunnel investigated the characterist
ics of flow and sampling efficiency of a low cost sediment trap that c
an be used in wind tunnels and field applications. The trap is constru
cted of thin sheet aluminum and has a wedge shape (32 degrees internal
inlet angle with a 20 x 500 mm rectangular inlet orifice that extends
40 mm beyond the wedge form. Relatively unimpeded airflow through the
trap is achieved by the large exit area (130 x 500 mm) which is cover
ed with fine, stainless steel mesh (62.5 mu m openings, 60% porosity),
and collected all but the finer (silt) sediment sizes. Despite its an
gular shape, the trap has good characteristics of flow and a very high
sampling efficiency (> 90%) over a wide range of wind velocities beca
use of its near isokinetic characteristics of flow. Results also indic
ate that this trap, and others that have wide side profiles, are very
sensitive to incident wind angle. Incident angles > 5 degrees signific
antly reduce the sampling efficiency and promote scour around the trap
inlet.