An anemometer is a device used to measure the speed of the wind. As with many scientific inventions, it's hard to pinpoint the first person to invent an anemometer. Sometimes the first inventor doesn't produce the best instrument, and improvements made by later scientists significantly enhance accuracy and ease of use.
Credited with devising the first mechanical anemometer is Italian art architect and mathematician Leon Batista Alberti, in 1450. In his device, the wind pushed against a disk, and an accompanying scale gave a relative strength of the wind as shown by the angle of inclination of the disk. In later years, several others "re-invented" this device, including Englishman Robert Hoke and Wolfius (in 1709).
A more advanced anemometer design using four cups attached by spokes to a central rod was invented by John Thomas Romney Robinson in 1846. Robinson was the director of the Armagh Observatory in Ireland. With his design, cups caught the wind and spun around faster the stronger the wind velocity. The number of revolutions of the rotating rod in a given period of time determines the wind speed, which is indicated on a dial connected to the rod. This basic design is still in use today in many weather stations around the world.
Leonardo da Vinci
Leonardo da Vinci took Leon Batista's anemometer design and improved upon it, around 1485. He was no doubt motivated to study wind velocity because of his fascination with flight. Rather than using a plate, da Vinci's design used a rectangular piece of wood dangling on an arched frame, on which was imprinted a scale. The stronger the wind, the further the wood arched up the scale.
A glass shaped like a "U" is filled with a liquid in this type of anemometer. One end of the tube lies horizontal and faces the wind. The other end is vertical. As the wind enters the open horizontal end of the tube, it causes a rise in pressure, and the wind flowing over the vertical tube's open end causes little or no change in pressure. Wind speed is indicated by the resulting change in liquid level. The tube anemometer had been known before, but in 1775 James Lind's tube device became well known. In 1892, William Henry Dines's anemometer, though different, was based on this early tube design.
Robinson's design used 4 cups, but in 1926, John Patterson, a Canadian, developed a 3-cup anemometer. Further improvements were made by Brevoort and Joiner (in America) in 1935, which increased accuracy.
Cup designs use a vertical axis of rotation. A "windmill-style" anemometer uses propeller-like blades on a horizontal axis. This enables the instrument to integrate a weather vane, so that both wind speed and direction can be indicated from a single device.
Today, newer designs use various techniques such as a "hot wire" sensor, but the basic "rotating vane" type, interfaced with digital technology, is very popular, especially in portable, hand-held units.
What Is the Function of the Anemometer?
An anemometer is a tool that is used for measuring wind speed. It is a common part of most weather stations.
Interesting Facts About Anemometers
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