A device for measuring wind speed. Meteorological instrument

A device for measuring wind speed and determining the direction of its blow is known as an observatory, or an anemometer. Applied such a device when it is necessary to control the parameters of the movement of air masses.

Principle of operation

Despite the variety of anemometers, which differ constructively, most of them work by the principle of determining the nature of the action of the air flow on moving rotating elements.

Devices of this category are able to determine the maximum current wind speed when blowing a stream in a certain direction. Individual models give indicators of volumetric air flow, flow temperature, humidity. Thus, a functional instrument for measuring wind speed is converted into a portable weather station.

Types

There are several separate types of devices that can calculate wind speed. Currently, the following types of instruments for this purpose are distinguished:

• Rotational;
• Vortical;
• Thermal;
• Dynamometric;
• Optical;
• Ultrasound.

Let's consider in detail the devices of each type, determine their capabilities, ways of operation.

Rotational anemometers

A meteorological instrument can be equipped with cups or blades that play the role of a sensitive element. The latter are movably attached to the vertical rod and connected to the meter. Moving the air streams causes such turntables to rotate around the axis. As the movement moves, the measuring mechanism records the number of revolutions during a certain time interval. The visual information is provided by a wind speed scale or a digital display.

Constructions of this type were invented long ago. However, despite the appearance of more sophisticated instruments, rotational anemometers still continue to be successfully used by meteorologists around the world.

Vortex anemometers

In such instruments, the measurement of the speed and direction of the wind occurs due to the effect of air currents on the light impeller, located in a vertical plane. As in the previous case, the rotation of the impeller, by acting on the gear system , transfers the data to the counting mechanism.

At the present time, manual vortex anemometers are most common. The latter are used to measure the speed of air flows in ventilation systems and pipelines, installed in ducts of industrial and residential objects.

Thermal anemometers

Heat appliances are not in high demand. Most often, the need for their application arises when measuring the indicators of slow air flow.

The thermal wind speed sensor functions according to the principle of measuring the temperature of the filament or a special plate, which is pressurized with air. At different flow rates, a certain amount of energy is released, which allows one or another temperature of the heat element to be maintained. In such a simple way, the wind speed is determined.

Dynamometer anemometers

The wind speed measuring device can also function due to the determination of the wind pressure indicators in the middle of the L-shaped tube sealed on one side. The data is obtained by comparing the excess air pressure outside and inside the cell.

A dynamometer for measuring wind speed is used not only in meteorology. Installed similar devices to ventilation systems and flues, where the volume flow rate and their speed are calculated.

Ultrasonic Anemometers

The principle of operation of devices of this category is based on the determination of the speed of sound at the receiver, depending on the flow of air masses. Here are the most highly accurate, modern devices that also allow you to fix the direction of wind flows.

There are three-dimensional and two-dimensional ultrasonic devices. The first provide an opportunity to obtain indicators of the direction of flow in three components. In turn, a two-dimensional meteorological instrument allows measuring the direction and speed of the wind only in the horizontal plane. Some ultrasonic systems calculate the airflow temperature.

Optical anemometers

Scientists-physicists, engineers involved in space programs, often resort to the use of laser optical devices for measuring the speed and direction of movement of air currents. Such devices operate according to the definition of the dependence of the scattered or reflected light from the mobile object on its speed. This method does not imply the direct action of gaseous, solid or liquid substances on the elements of the measuring device.

The scope of optical anemometers is extremely wide, beginning with the determination of the directions of the movement of substances in living cells and capillaries and ending with the calculation of the velocity of gases in the atmosphere.

Operation of laser devices helps with high accuracy to calculate the speed of air flows around mobile objects, in particular, vehicles, aircraft, space bodies. The calculations allow the researchers, engineers and mechanics to develop the most aerodynamic forms in the design of technology.

Tips for choosing

What should I look for when choosing a device for measuring the speed and direction of moving air flows? Of decisive importance here is the list of tasks that are put before the user. Depending on this, the following technical characteristics of the device are important:

• Maximum measuring range;
• Magnitude of errors;
• The possibility of application in various temperature conditions;
• The level of safety for the user when the device is exposed to aggressive environmental factors;
• Type: stationary or portable device;
• The degree of protection of the mechanism from the effects of atmospheric precipitation;
• The nature of the power supply of the device and the method of data generation;
• Dimensions of the device;
• The ability to calculate indicators at night (the presence of lights).

Currently, for work in extremely low temperatures, it is possible to use meteorological instruments with preheaters. For mines and mines, specialized anemometers are used that are able to function properly under high dustiness of the surrounding space and in an explosive environment. Such functional devices tolerate the effect of increased humidity and remain operable at significant temperature changes.

Eventually

As can be seen, depending on personal needs, it is possible to choose the most suitable device for fixing the air flow indicators. However, there are complications here. Since all anemometers are measuring instruments, they are subject to certification and certification in the relevant state institutions.