2D Ultrasonic Anemometer with Dynamic Temperature Compensation

We have designed an Ultrasonic Anemometer that measures both the speed and direction of the wind whilst compensating for the errors that occur due to ambient temperature. Currently, there are various kinds of anemometers available, rotary cup type being the most widely employed. But due to moving parts, they are adversely affected by weather conditions and air quality. Ultrasonic anemometers on the other hand, do not have any moving parts and are therefore robust and long lasting and are ideal for continuous air flow monitoring in remote areas. The aim of our design was to develop an anemometer with low complexity and high accuracy. The coupling of the continuous wave technique and the directivity property of ultrasonic transducers resulted in a minimal component count in our design. The limiting factor for this technique is that, calculations use the speed of sound that is affected by change in ambient temperature. Therefore, an inbuilt dynamic temperature compensation system is also included in our design. The compensation plays an important role in minimizing error, producing an error of only ±3% against an error of ±16.7% without temperature compensation. The accuracy of the instrument is within the range of commercially available anemometers and has a huge potential in low wind speed measurement applications.