Comparison between Ultrasonic Anemometer and Mechanical Wind Speed Measurement Sensors

Although ultrasonic and mechanical wind speed measurement sensors are similar at the basic conceptual level, due to the differences in their designs, their operating modes each possess unique characteristics. Therefore, it is of great significance to clarify the advantages and disadvantages of these two types of anemometers.

Ultrasonic Anemometer

Firstly, ultrasonic anemometers have the advantage of requiring less maintenance and exhibit a more excellent response ability when dealing with rapid gusts. The core difference lies in the fact that ultrasonic anemometers have no moving parts. Specifically, ultrasonic pulses are emitted from the sensor facing north, and the microprocessor is responsible for measuring the time it takes for the pulses to travel to the sensor facing south. The wind speed is then calculated based on the propagation time of the pulses between the two sensors. Factors such as wind speed and direction can affect the measurement time. However, due to the absence of moving parts, the measurement results of ultrasonic anemometers can be obtained instantly and with extremely high precision.

Mechanical Wind Speed Measurement Sensors

In contrast, mechanical wind speed measurement sensors have moving parts, including the cups used to detect wind speed and the wind vane used to determine vector changes. Whenever the wind direction changes, these parts will correspondingly produce physical movements to ensure the accuracy of the speed and direction readings. Although in terms of long-term measurement results, the precision of mechanical wind speed measurement sensors is roughly the same as that of ultrasonic anemometers, mechanical sensors have limitations due to the existence of moving parts and are not always able to effectively detect situations such as gusts and turbulence.

Comparison in Actual Observation

During the process of wind speed measurement, since mechanical sensors require a certain amount of time for physical startup and to record changes in wind direction, this leads to differences in the measurement results. For example, when encountering a storm with rapidly changing wind directions, the sensors in a mechanical anemometer need to first decelerate, stop, and then restart as the wind direction changes. It often takes several seconds to complete the recording and reporting of the change in wind direction. However, ultrasonic anemometers are able to immediately measure the change in wind direction.