Uncertainty and correction methods of wind direction and anemometer
Wind direction and wind speed are an important part of the natural climate. Their existence not only responds to the characteristics of atmospheric circulation, but is also one of the parameter indicators and energy sources for climate comparison in different places. For the observation of wind speed and wind direction, due to the differences in equipment, observation methods and measurement principles between wind anemometers and manual ones, it is inevitable that there will be differences in the observed values between them. Then the size of this difference and the reasons for the difference are worth exploring.
With the changes of the times, wind direction and anemometers are developing rapidly. New instruments are used in all walks of life in China. In particular, wind direction and anemometers are used to predict national meteorology and oceans. It is an important task. In order to make the wind direction and anemometer reliable data measurement For traceability and quality assurance, instrument calibration is a must, especially under dynamic conditions and calibration measurements are performed in wind tunnels.
Wind direction and anemometer uncertainty The uncertainty of the wind speed of the entire device relative to the standard should include the uncertainty of the measurement results of the standard instrument consisting of a second-class standard pitot static tube and a micromanometer, and the instability of the air flow in the wind tunnel. Uncertainty caused by uniformity and non-uniformity and uncertainty of the device.
Wind direction anemometer calibration method
(1) Only wind direction anemometers that have passed the visual inspection can perform the following calibrations.
(2) The installation position and requirements of the pitot tube and wind direction and anemometer in the wind tunnel calibrator: the pitot tube total pressure hole should be aligned with the direction of the air flow, the pitot tube probe axis is (25±5) mm away from the working section tunnel wall, and the pitot tube probe axis should be (25±5) mm away from the working section tunnel wall. The support pole should be installed vertically and firmly on the wall of the working section of the wind tunnel.
During the application process of the wind direction and anemometer, the protective layer should be strong and uniform, and there should be no delamination or obvious defects such as rust. The installation part and use should be installed correctly in strict accordance with the requirements of the instruction manual to avoid causing data distortion. The error increases. The application of wind direction and anemometer in agricultural production plays an important role in early prevention and protection of crops.
