Device for measuring wind speed (anemometer): types, instructions. Vane anemometer

What is the device used for?

Today, the anemometer device can be found in various industries:

• At meteorological stations that operate to observe the weather.

• At airports. They are used by the flight safety service.

• To determine draft in ventilation systems in the mining and coal mining industries.

• In construction, anemometers are used to ensure safety: the device is mounted on the top of the crane boom. When the wind speed reaches above the specified parameter, work is prohibited.

• In agriculture, this device is used when treating crops with chemical protection agents and fertilizers.

This is a list of the main areas where the speed measuring device is used. Some types can additionally measure wind direction in different planes and air temperature. The units of wind speed - meters per second - are used in instruments of all types.

Purpose of the tool

An anemometer is a device for measuring wind speed, translated from ancient Greek as “wind meter”

. But the Greeks have nothing to do with it, since the device was invented by the Irish astronomer John Robinson in the mid-19th century. The purpose of the invention was to determine the force, or scientifically speaking, the speed of the wind. Today it is used in various sectors of the economy:

• At meteorological stations that monitor the weather, the results of which sometimes result in storm warnings.
• In airfield flight safety services.
• During the operation of ventilation systems and air conditioning stations of industrial facilities, metro tunnels.
• To control the ventilation of tunneling drifts used in the mining and coal mining industries.
• In the construction industry. A spinner installed on a tower crane, if the permissible wind load is exceeded, warns the operator of the danger using a light and sound signal.
• Workers in the agricultural industry use an anemometer when pollinating crops with fertilizers and chemical plant protection products.
• It is used in some sports involving the use of wind power: paragliding, sailing regattas, ice boat racing, and so on.

Design and principle of operation

An anemometer allows you to measure wind speed and direction. It captures the speed of the air flow, after which it processes the received information and transmits it to the recording device.

The main components of the structure are only three blocks:

• A unit that directly measures the air speed at rest. More precisely, the device detects the disturbance of air masses, which is formed as a result of the movement of air flow.

• A converter that serves to convert air displacements into a physical parameter.

• A recording device that receives a signal from a transducer.

A kind of chain is formed, at each stage of which a separate block plays its role.

How is wind formed?

The main reason for the formation of wind is the uneven distribution of atmospheric pressure. The sun's rays, reaching the surface of the Earth, heat the ocean and land. At the same time, the temperature in different parts of our planet increases unevenly.

Wind formation

For example, the equator zone and the corresponding belts are heated the most. The temperature of ocean waters increases less rapidly than the temperature of land, but bodies of water retain heat longer.

Thus, the air masses are also heated unevenly. Zones with different pressures are formed, resulting in air circulation. Thus, heated flows (ascending) from the low pressure zone rush upward. Meanwhile, the cooled air (downdrafts) sinks down and rushes into the low pressure area.

The Earth's atmosphere does not stop for a second. The air circulation process is global in nature. When massive currents of warm and cold air collide, winds of varying intensity are created.

Variety of models

Depending on the principle of operation, the device for measuring wind speed is manufactured in three versions:

• Mechanical. Due to the movement of air in them, individual elements rotate. This category includes cup and vane (or blade) anemometers. They differ from each other in the design of the element that perceives air flows.

• Heating (or thermal). Their design includes a heating element (usually a simple incandescent wire). Under the influence of moving air masses, this element cools down. The device determines the degree of temperature reduction.

• Ultrasonic, which measures the speed of sound. Sound passing through moving gas has different speeds. If it moves towards the wind, its speed will be lower. Conversely, when moving in the same direction as the wind, its speed will be higher than in still air.

Meaning in nature

Wind is the most important natural factor that affects the components of nature: climatic conditions, geological processes, plants, animals, etc.

Wind soil erosion

The main consequences of the influence of winds:

1. The emergence of strong ocean currents that determine the climate of adjacent zones.
2. Soil erosion due to blowing of fine particles.
3. Formation of new relief forms. For example, the transport and deposition of sand by wind leads to the formation of sand dunes.
4. Transfer of dust from deserts and air pollution. For example, in the summer trade winds blow in the Northern Hemisphere. At the same time, they are gradually approaching areas of subtropical deserts. As a result, dust from the Sahara reaches southeastern North America throughout the season.
5. Spread of fires. Wind is one of the main factors that influences the rapid spread of fires, especially forest fires.
6. Effect on plants. Air currents disperse the seeds of some plants, limit the growth of trees, and can also cause mechanical damage by transported particulate matter.
7. Effect on animals. The wind increases the cold combined with low temperatures - this is the main aspect of its influence on the animal world. For example, penguins, birds, and insects are forced to adapt to the influence of the wind. Some species benefit from the movement of air masses - deer recognize predators from afar due to their acute sense of smell.

Classification

The device for measuring wind speed has a sensor in its structure that is in direct contact with the air flow. Depending on the type of this sensor, the following types of anemometers are distinguished:

• Rotating, in which individual structural elements begin to rotate under the influence of wind speed.

• Ultrasonic, which is also called acoustic.

• Heating, they are also called thermal.

• Optical, which in turn are divided into laser and Doppler.

• Dynamic, whose operating principle is based on a Pitot-Prandtl tube.

• Float

• Vortex.

This is a list of devices that can be found currently.

Vane

Long nail - wooden pole - wooden beads - plywood - hammer - ruler - shoe knife - wood glue - compass

1. Cut out the parts shown in the drawing below from plywood. The width of the slots should be equal to the thickness of the plywood.

2. Assemble the weather vane as shown in the picture. Secure the parts together with glue.

3. Balance the vane on the nail head to find its center. Drive a nail in this place, stringing a bead on it on both sides of the weather vane, as shown in the figure. The weather vane must be mounted on a pole so that it can rotate freely.

4. Using a weather vane, determine the direction of the wind. His nose indicates the direction from which the wind is blowing. The wind from the south is called the south wind.

Vane anemometer

This device is capable of determining air speed, which ranges from 0.5 to 45 m/s. In addition, this device allows you to measure temperature, which ranges from minus 50 to plus 100 degrees.

The design of the anemometer is such that the wind is sensed by a bladed impeller. This is a small, lightweight wheel that is protected from mechanical stress by a metal ring. The principle of its operation resembles a fan or a mill. Under the influence of wind, the impeller begins to rotate. Through a system of gear wheels, its rotation is transmitted to the arrows of the counting mechanism.

The manual anemometer is designed so that the counting mechanism is located next to the impeller. This creates a barrier to the wind, thereby limiting the operating range. Such devices can measure wind speeds that do not exceed 5 m/s. These devices are suitable for measuring air flow in ventilation shafts, pipelines, air ducts and so on.

The digital vane anemometer is designed in such a way that the sensor is built inside the device or is remote. Thanks to this design, there is no barrier to the wind. Therefore, the device measures flow, the speed of which can reach 45 m/s.

Lobed

In this device, the influence of wind is perceived by a blade impeller. Its operating principle is similar to the cup device. Due to the fact that the axis of rotation of the impeller is parallel to the air flow, the mechanical counter of the hand tool is located in close proximity to the blades (at the rear). Therefore, it is some kind of obstacle to the wind, which limits the operating range. A hand-held paddle anemometer can measure average wind speeds not exceeding 5 m/s.

The digital vane anemometer does not have a mechanical revolution counter that prevents air movement, so the flow speed measured by the device reaches 45 m/s. In this case, the paddle sensor can be built-in or remote. It is possible to measure average, maximum and minimum speed.

Cup type devices

A cup anemometer is capable of making measurements only in a plane that is perpendicular to the axis of rotation. The design of the device consists of 4 cups in the shape of hemispheres, which are mounted on symmetrical cross-shaped rotor spokes.

The first versions of this device appeared back in 1846. Their creator is John Robinson. It got its name due to the external resemblance of the blades to a cup. The doctor assumed that the rotation of the cups was not affected by their size. In his opinion, the speed of rotation of the cups is three times less than the speed of the wind. This theory was later disproved. It has been proven that the device has a coefficient that ranges from 2 to 3.5.

In 1926, John Patterson proposed a three-cup rotor. He noticed that the maximum torque of the cups was achieved when they were rotated at an angle of 45 degrees in relation to the movement of the wind.

In the early nineties of the last century, Derek Weston improved a cup device for measuring wind speed. Its improvements made it possible to additionally measure the direction of wind movement. He achieved this in a simple way - he placed a flag on one of the cups. When rotating, the flag moves half a turn with the wind, and the second - against it.

Hand-held cup instruments count the number of revolutions completed in a given period of time. In improved anemometers, the rotor is connected to various types of tachometers. These devices are able to instantly show wind speed and its changes in real time. Measurement interval – from 0.2 to 30 m/s.

Table for determining wind speed by external signs

Meteorological devices include a device for measuring wind speed called an anemometer. Translated from ancient Greek, the definition literally means “wind gauge.” Despite the name, the device was invented only in the 19th century. It was invented by Irish astronomer John Robinson to determine wind speed.

Thermal appliances

The operating principle of such anemometers is to determine the electrical resistance of the wire. This value changes depending on the temperature, which is reduced by the moving air flow. It is similar to how on a hot sunny day the breeze cools your skin.

The design of the anemometer is a metal filament (made of platinum, nichrome, silver, tungsten and other metals), which is heated by electric current to a temperature exceeding the ambient temperature.

Devices of this type have one significant drawback - low strength under mechanical stress.

Selecting a weather station

Nature does not have bad weather, as we know. There are clothes that are not appropriate for the weather. And every morning before leaving the house, we determine how to dress for the day.

To do this, someone intensely peers out the window, trying to make out the approaching clouds and at the same time the temperature of the window thermometer, someone looks on the Internet at their favorite weather site, someone, in the old fashioned way, listens to weather forecasters on the radio or TV. And often these actions do not save us from the fact that global cooling suddenly gives way to global warming, contrary to forecasts (we know that weather forecasters make mistakes only once, but every day). Or the lack of precipitation promised for the coming week is filled with record-breaking rain, once again tarnishing the reputation of weather services. And we suffer from this - again finding ourselves in the rain without an umbrella, or in the snow in light shoes...

Weather forecasting - for a day, a week, a year - has occupied the minds of people since ancient times. But only in the 16th and 17th centuries, with the invention of the barometer and thermometer, instrumental observations began to be recorded. Scientists established a clear connection between fluctuations in the "height" of the barometer and changes in weather, and this marked the beginning of synoptic forecasts.

It was observed that the wind always blows from an area of ​​high pressure to an area of ​​low pressure, forming an air vortex with winds moving towards the center, counterclockwise - this phenomenon was called a cyclone. In the central part of the cyclone, the air rises, expands, cools and condenses into steam - this is how clouds form. Therefore, in the area where the cyclone passes, cloudy, stormy weather prevails: cool in summer with rain, warm in winter with snow.

But everything is not so simple - based on pressure fluctuations alone, one can only judge that the weather will change. To predict the weather, you have to take into account several parameters: changes in atmospheric pressure and air temperature, time of year, wind and cloudiness. And this is exactly what a weather station .

There are two types of weather stations: analog and digital. This review is dedicated to the second type - smart little gadgets that replaced the extensive arsenal of control devices: thermometer, barometer, hygrometer, anemometer. Now all these functions are performed by one device. In addition, in addition to displaying current readings, they remember readings for a given period, and based on additional measurements they build a forecast for weather changes. And thanks to its compact size, it can easily be placed in a place convenient for you: on a bedside table, desktop or on the wall.

BASIC FUNCTIONS OF WEATHER STATIONS

Manufacturers offer many models of weather stations, varying in functionality. Some devices only measure the temperature and humidity in the room (thermal sensors), others not only record the microclimate of an apartment or office, but also show complete information about what the weather expects outside. By analyzing the measurements received, the weather station generates a forecast of possible weather changes, so it is important that as many values ​​as possible are recorded.

The weather station receives the results of measuring climatic values ​​from sensors , the number of which reaches up to 5. Sensors can be either built into the body of the weather station or remote. Remote sensors are divided into:

• wireless – designed as a separate device in a housing, powered by batteries or rechargeable batteries. The operating radius is several tens of meters;

• wired - made in the form of a thermal probe connected by a wire to the body of the weather station. The wire is about a meter long.

Wireless sensors are more convenient to use because they operate over a greater distance than wired ones. It is not difficult to place the wireless sensor in the right place (it is equipped with special grooves for fastening), and the housing will protect it from external influences.

Weather stations working with 3-5 wireless sensors are suitable for those who need to control the microclimate of several places besides the house and the street - for example, a greenhouse, cellar or garage. With such a device, unexpected drops in temperature will not go unnoticed. When purchasing a device, pay attention - most often, the weather station includes 1-2 sensors, the rest, as needed, are purchased separately.

ADDITIONAL OPTIONS

In addition to measuring climate indicators, weather stations are often equipped with an organizer that displays additional information: weather indication, moon phases, calendar, clock, alarm clock. Thanks to these options, you get a multifunctional device that will wake you up, remind you what day of the week and date it is, and tell you the weather. And if you consider that there are units with a built-in radio, then we can safely say that the weather station more than replaces half of the usual desktop instruments.

for displaying information on the screen: in the form of numbers and symbols (the weather mode is shown as a picture: sun, cloud, raindrops, snowflake). The most convenient option is if the device supports manual configuration, and you can select the desired view.

Some models are equipped with light or sound indication . This function will help you not to miss the moment of changing an important parameter. Once you program it, you will be notified of pressure surges, changes in humidity, and changes in temperature.

The backlight will help you see the characters on the screen.

When choosing a device, pay attention to the power type :

• Batteries or accumulators. This type of power supply will free you from unnecessary wires and make the device independent from the whims of electricians (turning off the lights will not leave it without power);
• From the mains. With this type of power supply, you do not need to remember to replace batteries, but the device will have to be placed close to an outlet (which affects mobility).

Some models of weather stations are equipped with an interesting function - an image projector . By turning on the projector, you will project information onto any surface where you direct the beam. If you wish, you can direct the projector beam at the wall or ceiling in the evening before going to bed. Then, if you wake up at night, you won’t need to peer at the device screen, considering how much time is left to sleep - just glance in the right direction.

No less interesting are models that actually do without a screen - weather information is displayed on the body itself:

The most modern weather stations have a USB interface (for connecting to a computer and analyzing measurements) and the ability to connect to the Internet - for transferring information to a smartphone or email.

QUESTION PRICE

Conventionally, based on cost, weather stations are divided into:

• models in the inexpensive price segment, up to 2500 rubles. Such devices are mainly focused on use for monitoring temperature and humidity; the functional features are not very wide: the organizer of almost all models includes only a clock, an alarm clock, and a calendar. The maximum number of connected sensors is up to 3.
• models in the middle price segment, from 2,500 to 10,000 rubles. Almost all devices in this category can be called personal weather centers, which, in addition to recording temperature and humidity, measure pressure and help predict the weather. The functionality is different, but for most devices it can be said that: the organizer includes all possible functions, the information output is programmable, the maximum connected number of sensors is up to 5. Measurement data is stored and can be displayed both digitally and graphically. Some models can record wind strength and speed. There are models with interesting design solutions and a built-in projector.
• models in the expensive price segment, from 10,000 rubles. Devices in this segment differ not so much in the number of functions as in the quality of measurements; the main feature is high accuracy.

Technology has long and firmly entered our world, so why not try to use another smart gadget? Moreover, it is truly useful and will find application in everyday life.

Ultrasonic anemometers

The operating principle of these devices is based on determining the speed of sound in a moving air flow. That is why this anemometer is also called acoustic. When sound moves in the same direction as air, its speed increases. When moving towards the wind, the speed of sound decreases. Thanks to this, the time it takes to receive the ultrasonic pulse is measured. The device is connected to a computer to process the received data.

The sensor can perform several functions. Depending on their number, several types of sensors can be distinguished:

• Two-dimensional, which are able to determine the speed and direction of the wind.

• Three-dimensional, which determine all three components of the wind speed vector.

• Four-dimensional, which, in addition to the indicators of the previous type, can measure air temperature.

Ultrasonic devices measure wind speeds up to 60 m/s.

Table for determining wind speed using a Wild weather vane.