The Beaufort system has undergone several modifications to standardize its measurement scale and to allow for its use on land. Users of this scale look for specific effects of the wind on the environment to determine speed. Wind speed is commonly measured with an anemometer . An anemometer consists of three open cups attached to a rotating spindle. The speed of roation is then converted into a measurement of wind speed.
Wind direction is measured with a wind vane .
On the photograph above, the wind vane instrument has a bullet shaped nose attached to a finned tail by a metal bar. Beaufort wind speed scale. Thus, a wind from the north blowing toward the south is called a northerly wind. Figure 5n-3 describes the sixteen principal bearings of wind direction. Most meterological observations report wind direction using one of these sixteen bearings.