Wind Speed Meter

Thermal wind speed meters are well suited for measuring low speeds. In these devices, a wire or semiconductor, the electrical resistance of which is temperature-dependent, is heated. The stronger the wind blows, the faster the heat is dissipated. There are two basic methods. Either the heating current is kept constant and the change in voltage is measured by the changed resistance value or the temperature is kept constant and the heating current required for this is measured. The second option is technically more complex, but covers a larger measuring range and automatically measures the temperature of the incoming air as well. Thermal wind meters with several heat sensors can also measure the wind direction in two or even three dimensions. They are thus also suitable for testing flow angles on components and for measuring turbulence.

Wind speed can also be determined from the pressure difference between still and flowing air. Special Pitot tubes or Prandtl tubes, the measuring tip of which is blown directly by the wind, are used for the measurement. Pitot tubes are particularly suitable for measuring high speeds. These wind speed meters are therefore used for measuring strong winds and gusts as well as on aircraft and racing cars and in the process technlogy.

In most cases, the field of application already determines whether the wind speed meter is permanently mounted or whether it is used for measurements at different locations. In the case of the wind meters permanently mounted on buildings, the digital measurement data is usually transmitted either via cable or wirelessly to an evaluation unit. Some stationary wind meters also directly control ventilation or shading systems or alarm devices via pulse or analogue outputs when limit values are set. Mobile wind meters are often easy-to-use handheld devices that show the measured value directly on the display. Many of them are equipped with an internal memory so that the measured values can be saved and transmitted later. However, small mobile data loggers without a display are also available. These store the wind speed at set intervals and are later read out on the computer. The setting of these wind meters for continuous measurements and the evaluation of the data are usually done conveniently via the associated software.

Many wind meters display the air temperature as an additional value; the other devices also display the air pressure or the air humidity. For orientation measurements at workplaces, there are combined devices that also measure, for example, sound level, humidity and illuminance. For certain environmental measurements, the wind speed meters are also available that can indicate the height above (or below) sea level relatively accurately.

A famous meteorological device, anemometer, or wind speed measuring device finds its application in many spheres where it goes about moving air masses dand where the speed of the air should be measured.

Among the variety of designs there are models that find frequent application and those that are suitable mostly for the laboratory tests. Wind speed meter with thermo-sensor, as follows from the name, is especially suitable for application where not only the speed, but also the temperature of the air is important. It is convenient for both, meteorological measurements as well as targeted measurements at particular locations, for example ventilation systems, or for inspections before the HVAC system’s commissioning. The meter can be applied for maintenance and repair of aerodynamic installations and equipment. Due to the variety of parameters that can be measured with the help of the thermos-sensor, the wind speed meter can also be used for checks of the compliance with the norms and health regulations in the workplace and thus, detection of faults and malfunctions in the ducts and channels, assessment of the condition of engines, for example, in aviation.

The main principle of the thermos-sensor is that the temperature change happens when cooler air mass influences the heated element of the meter, and thus the energy is released. To avoid the temperature drop and to maintain it on the desired level, the regulator is activated. The thermo-sensor may be affected by the air masses coming from different directions, when a so-called turbulence effect happens, and that is why it is often used for this kind of measurements.

Due to a rather simple, but very effective construction of the measuring device, it has become possible to measure the wind speed and many parameters, characterizing moving air masses where it is required or desired. The operating principles of the wind speed sensors lightly differ, but they all perform an important function and wherever it is necessary to check the speed of the wind, or carry out monitoring over a certain period of time, they find an application.

Сup anemometer is one of the most widely spread types of anemometers, the application of which is very versatile, and ranges from meteorological monitoring to sport activities, in which wind plays a decisive role. Outdoor conditions do not depend on people and that is why continuous monitoring of the wind speed with accurate measurement results, especially for particular tasks, is so important. At the same time, wind speed meter with cup sensor is also convenient to use there where the slightest deviations from the norm should be detected and eliminated immediately, since it goes about safety, health and comfort of people, for example, at the enterprises.

In the case of electronic devices, there is no need for the operator to calculate the wind speed, since the devices registers the number of rotations of the cups under the influence of the air mass and displays the final result, which saves a lot of time and excludes the possible errors. Cup sensor is not the best choice for very small speeds, but its advantage is that it copes with wind or air mass blowing from any direction. It is stable and does not require additional adjustment.