Top 6 Wind speed sensors

What is an anemometer?

An anemometer is an instrument that measures the velocity of air, sometimes called a wind anemometer. The earliest anemometers originated hundreds of years ago and were used to roughly measure wind. With the continuous updating of technology, the current anemometers can provide a variety of highly accurate data. There are many types of anemometers. Some are very common, while others are rare. Finding an anemometer that suits your specific needs is often a daunting task.

6 different types of Anemometer:1.Cup Anemometers

It is the most common type of anemometer. The cup-rotating anemometer was first invented by Ruby Sun in England. It was four cups at the time. Later, John Patterson removed one cup and used three cups instead. The three parabolic or hemispherical empty cups that are angled to each other and fixed on the frame are all along one side, and the entire frame and the wind cup are mounted on a freely rotatable shaft. The wind cup rotates around its axis under the action of wind, and its speed is proportional to the wind speed. Rotation speed can be recorded with electrical contacts, tachogenerator, or photoelectric counter. The three-cup anemometer is a commonly used measuring instrument in weather stations.

2.Propeller anemometers

It is an anemometer with a set of three-blade or four-blade propellers rotating around a horizontal axis. The propeller is installed on the front of a wind vane so that its rotating plane is always facing the direction of the wind, and its rotation speed is proportional to the wind speed.

There are two types of wind speed: indirect heating and direct heating. The indirect heating type is generally manganese copper wire, its resistance temperature coefficient is close to zero, and its surface is additionally equipped with temperature measuring elements. The direct heating type is mostly platinum wire, which can directly measure its temperature while measuring the wind speed. The anemometer has high sensitivity at low wind speeds and is suitable for measuring small wind speeds. Its time constant is only a few hundredths of a second, and it is an important tool for atmospheric turbulence and agrometeorological measurement.

Advantages: It is a high-speed anemometer, which can be measured even at low speeds. Portable and easy to operate. No special software is required.

Disadvantages: The hot-wired anemometer is easily affected by the ambient temperature, and its temperature drift is one of the most important sources of error. Secondly, this anemometer is expensive and costly.

3.Handheld Anemometers

The handheld anemometer is a portable wind speed measuring device. From a technical point of view, the anemometer can read speeds up to 30 m/s. The speed is about 108 miles per hour, and the accuracy is about 2%. This anemometer is battery-powered. If you want to camp, hike, sail, and hunt outdoor activities that may need to know the wind direction or wind speed information, these kinds of equipment are the best choice.

4.Ultrasonic anemometers

It is a wind speed and wind direction measuring instrument that uses sending sound pulses to measure the time or frequency (Doppler transform) difference at the receiving end to calculate wind speed and direction.

The propagation speed of sound waves in the actual atmosphere is equal to the sum of the propagation speed of sound waves in the static atmosphere and the airflow speed in the atmosphere. Therefore, within a certain distance, there is a difference between the time required for sound waves to propagate downwind and upwind. The air velocity can be obtained by measuring this time difference, that is, the air velocity measurement can be realized by measuring this time difference, which is the working principle of the ultrasonic anemometer.

5.Pressure Anemometers

The pressure anemometer uses the difference between the total pressure of the wind and the static pressure to measure the wind speed. Through the double pitot tube, one nozzle is facing the direction of the airflow and senses the full pressure of the airflow, and the other nozzle is behind the direction of the airflow. Because of the suction effect, the induced pressure is lower than the static pressure.. The pressure difference induced by the two pipes has a certain relationship with the wind speed.

The most commonly used pressure anemometer is the Pitot tube. The Pitot tube is named after its inventor and French engineer Henri Pitot. It is composed of a total pressure probe and a static pressure probe. The difference between the total pressure (stagnation pressure) of the flowing air and the static pressure, that is, the dynamic pressure, is used to measure the wind speed. At the top of the pitot tube head, facing the incoming flow, a small hole is opened, which is used to feel the total pressure of the fluid. At about three times the pipe diameter from the head, several small holes are opened around the pipe wall.

These small holes should be perpendicular to the wall and used to feel the static pressure of the fluid during use. The small holes on the head and the small holes on the sidewall are connected to two pipelines that are not connected and are respectively connected to the two ends of the differential pressure gauge. According to the differential pressure gauge readings and calculations using related formulas, the measured point can be obtained.

Advantages: high stability. It is suitable for the measurement of the positive pressure, negative pressure, and differential pressure of the gas within the pressure range of 3000Pa, as well as the measurement of wind speed and air volume.

Disadvantages: The use environment is relatively single and not very useful.

6.Tube anemometers

The tube anemometer is designed for pipe wind speed measurement. The high-precision wind speed measuring unit is sensitive and can quickly and accurately measure the small wind speed with good stability. At the same time, the real-time air volume value can be calculated according to the cross-sectional area of the pipe that is set to be measured. The tube anemometer adopts an anti-interference circuit design, which can withstand various strong electromagnetic interferences such as on-site inverters. It is free of screw terminal wiring and is more convenient to use.

The tube anemometer uses the hot-wire balance principle to measure wind speed. The response speed is fast, and the starting wind speed is small.

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