Acoustic Anemometer
The wind speed component in the direction of sound wave propagation will increase (or decrease) the sound wave propagation speed. Acoustic anemometers made with this characteristic can be used to measure the wind speed component. Acoustic anemometers have at least two pairs of sensing elements, each pair including a sounder and a receiver. Make the sound waves of the two sounders travel in opposite directions. If one group of sound waves propagates along the wind speed component and the other group just goes against the wind, the time difference between the sound pulses received by the two receivers will be proportional to the wind speed component. If two pairs of elements are installed in the horizontal and vertical directions at the same time, the horizontal wind speed, wind direction and vertical wind speed can be calculated respectively. Due to the advantages of anti-interference and good directionality of ultrasonic waves, the frequency of the sound waves emitted by the acoustic anemometer is mostly in the ultrasonic section.
