We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

A anemometer It is an instrument used to measure wind speed, direction and force. It can be a paddle wheel, which consists of an impeller with oblique blades, or the so-called Robinson, consisting of four hemisphere shaped cups fixed to four radial arms.

When the wind blows, it rotates the vane wheel or the axis of the vane wheel with speed proportional to that of the wind. This movement is transmitted to some mechanism capable of indicating this speed on a graduated scale.

The wind speed can also be measured by the air pressure on an L-shaped tube, with one end open towards the air stream and the other connected to a pressure measuring device. This model was invented by the French physicist Pitot (1695-1771) in 1732. Comparing the pressure exerted by the air, which impacts on one of the mouths, with the normal atmospheric pressure, the wind speed is obtained.

Other anemometers use two filaments heated by an electric current, made of a material whose resistance varies greatly with temperature. One of the filaments is exposed to the current, while another is protected from the air. The temperature difference, and therefore the resistance between the two filaments, gives an indication of the air velocity.

Anemometers are especially used in meteorology and air navigation.

◄ PreviousNext ►
Anecoic (camera)Angstrom (unit of measure)