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Anemometry is the accurate measurement of the speed of the wind across the earth’s surface, the instrument used to achieve this is known as an anemometer. The name is derived from a Greek word, ‘anemos’ which translates as ‘wind.’ Anemometers can measure both the speed of the wind and its pressure.
These important instruments are an essential part of a weather station and help tremendously in allowing accurate weather reports and forecasts. The task of measuring wind speed accurately is not without its difficulties and designing suitable instruments to perform the task has been problematic. It is more difficult to measure air moving at lower speeds than at higher ones and the science involved in this whole process is quite complex.
Developments have gone on steadily over the years since the first cup anemometer was invented in the middle of the nineteenth century and the introduction of sophisticated electronics has helped enormously. The rotating cup anemometer is the one that most people will recognise and can be fixed on a rigid post or can be handheld. The rotating cups rate of revolution is measured electronically and can be recorded remotely by a computer.
The vane anemometer acts in a similar way to the cup instrument but has a propeller at the front, as on an aircraft, and a vane at the opposite end to keep the propeller facing into the wind.
The most sophisticated anemometers available today utilise a laser or ultrasonic air waves to produce their measurements.
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