|MadSci Network: Earth Sciences|
Wind velocity is measured by use of a pitot tube. It is essentially an open tube that is held perpendicular to the wind direction. The other side of the tube measures the decrease in pressure due to the flow over the open side. It uses basic bernoulli principles to calculate the wind velocity necessary to create the decrease in pressure. [Moderator note: There are other types of anemometers. One common type uses rotating "cups", with the frequency of rotation related to wind speed.]
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