Basic Knowledge of Digital Anemometers
Wind Measurement Methods
Wind speed (flow velocity) measurement includes average wind speed testing and turbulence component testing (wind fluctuation ranging from 1 to 150 kHz, distinct from general airflow variation). Thermal anemometers are designed for average wind speed measurement. Common measuring principles include thermal, ultrasonic, impeller, and pitot tube types. Among these, thermal anemometers operate based on heat dissipation. The following introduces each wind speed measurement method in detail.
Thermal Anemometer
This method measures wind speed by detecting resistance changes of an energized sensor cooled by airflow. It cannot provide wind direction
data.Featuring portability and high cost‑effectiveness, it is widely adopted as a standard anemometer type.
Sensing elements of conventional thermal anemometers may use platinum wire, thermocouples or semiconductors. Our company adopts coiled platinum wire, which delivers excellent chemical stability. It provides superior long‑term stability and reliable temperature compensation performance.
Ultrasonic Type
This technique calculates wind speed by measuring the propagation time of ultrasonic waves over a fixed distance; airflow causes propagation delay.Wind direction can be determined with a three‑dimensional layout.
The relatively large sensor structure tends to generate turbulence around the measuring area and disturb airflow patterns, limiting its applicable scenarios. This type has low market popularity.
Impeller Type
Working on the windmill principle, it measures wind speed by detecting impeller rotational speed.It is commonly used for meteorological observation.
With a simple structure and low cost, it suffers from low measurement accuracy. It is unsuitable for low‑speed airflow detection and subtle wind speed fluctuation monitoring, resulting in limited application popularity.
Pitot Tube Type
Small holes are arranged perpendicular to the incoming flow direction, with internal thin tubes for separately collecting total pressure and static pressure. Wind speed is calculated by measuring the differential pressure between the two.
It features a simple principle and low cost, but the probe must be installed strictly perpendicular to the airflow; misalignment will cause significant measurement errors. It is not recommended for general‑purpose use.
