The anemometer is a device used to measure wind intensity.
An anemometer is a device used in the field of meteorology to measure the intensity of the wind . These elements have several blades equipped with cups, which look like small metal bowls: when the wind blows, the anemometer blades begin to rotate. Recording the number of turns allows the wind speed to be calculated.
Anemometers of this type, which are also known as vane anemometers , are the most used in the field of meteorology. Depending on the model, the reading and recording of the number of turns that the wind produces in the small windmill is carried out differently, and this also gives rise to different anemometer names. This variety is typical in inventions as old as this one.
In some cases, said value can be reflected directly on a counter, or printed on a strip of paper (which is called anemogram ), and there are also completely electronic devices, which have digital screens to express the results. When the anemometer has a graphic type recorder, it is called an anemometer .
Types of anemometers
There are, however, other types of anemometers. In airplanes, anemometers equipped with a nickel or platinum wire that is heated by electricity are used. The wind, by cooling it, produces a change in its resistance. In this way, the current that runs through the wire is proportional to the speed reached by the wind.
There are devices of this kind that use a splitting laser beam . The return of the laser to the anemometer is slower due to the air molecules: the difference registered between the relative radiation in the anemometer and the return of the radiation allows us to estimate the speed of these air molecules.
The device that, in airplanes, is used to calculate the speed of travel is also called anemometer. In this case, the anemometer has a different appearance and design, and allows the comparison of dynamic pressure (i.e. that of air impact) and static pressure using a Pitot tube .
A combined intake created in 1732 by the engineer Henri Pitot is known as a Pitot tube and is used to calculate the total pressure (also called backwater, remnant or stagnation), which is equal to the sum of the static and the dynamics.
It should be noted that the Beaufort scale makes it possible to classify, according to the wind speed detected by the anemometer, whether there is calm, breeze, strong wind, storm or hurricane , among other states.
There are different types of anemometers.
The Beaufort scale
In about 1805 , the English hydrographer and naval officer Sir Francis Beaufort created the scale that bears his name; Until then, naval officers were restricted to the results of their own observations, which they carried out with some regularity, but were not based on any scale, and therefore their measurements lacked objectivity.
Initially, the Beaufort scale did not include different values of wind speed, but instead indicated a series of qualitative conditions according to the impact they could have on the handling of vessels, and assigned them a number from zero to twelve, the smallest being "barely enough to carry out maneuvers" and the largest, "impossible to hold the sails."
Over time, this scale became an essential part of the logbooks of the British Navy and since the 1850s it transcended the limits of naval use, thanks to the association of its values with the number of rotations provided by the anemometer.