The anemometer is a weather anemograph or device used for weather forecasting and , specifically , to measure wind speed. It is also one of the basic flight instruments flight heavier -than-air aircraft.
In meteorology , it is mainly used cup anemometers or reel kind of tiny windmill blades with three cups on which the wind acts ; the number of turns can be read directly on a counter or registered on a strip of paper ( anemogram ) , in which case the device is called anemograph . Although there are also electronic type .
To measure the sudden changes in wind speed , especially in the turbulence , is resorted to anemometer filament , consisting of a platinum or nickel electrically heated : wind action has the effect of cooling it and do so vary their resistance ; therefore, the current flowing through the wire is proportional to the wind speed.