Anemometer Wind Direction Uncertainty and Calibration Method
Wind direction and wind speed are an important part of natural climate. Its existence is not only a response to the characteristics of atmospheric circulation, but also one of the parameters 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 the use of wind direction anemometers and manual use, 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 develop rapidly and new instruments are used in all walks of life in China, especially the use of wind direction and anemometers in forecasting national meteorology and oceans is an important task. In order to make the reliability data measurement of wind direction and anemometers have For traceability and quality assurance, instrument calibration is mandatory, especially under dynamic conditions, with calibration measurements in a wind tunnel.
Uncertainty of wind direction and anemometer The uncertainty of the wind speed of the whole device relative to the standard should include the uncertainty of the measurement results of the standard device composed of second-class standard Pitot static pressure tubes and micromanometers, and the instability of the airflow in the wind tunnel. Uncertainty caused by sex and inhomogeneity and device uncertainty.
Calibration method of wind direction anemometer
(1) Only the wind direction and anemometers that pass the visual inspection can be calibrated as follows.
(2) The installation position and requirements of the pitot tube and wind direction anemometer in the wind tunnel calibrator: the total pressure hole of the pitot tube should be aligned with the direction of the airflow, the axis of the pitot tube probe should be (25±5) mm away from the wall of the working section, and the pitot tube The 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 anemometer, the protective layer should be strong and uniform, and there should be no delamination, obvious defects such as rust, etc. The installation part and use should be installed correctly in strict accordance with the requirements of the instruction manual, so as not to cause data discrepancies. The error increases. The application of wind direction anemometer in agricultural production plays an important role in the early prevention and protection of crops.
