Blowout is of great concern in the measurement of dustfall by using de
position gauges. in this paper a simple model is proposed to predict t
he blowout wind speed of a gauge over a wide range of operating condit
ions and a better understanding of the blowout mechanism has been obta
ined. The computational results show reasonable agreement with the exi
sting experiment data, bearing in mind the many simplifying assumption
s that have been made.