Summary of comparative analysis of ultrasonic wind speed and direction sensors:
1. Ultrasonic wind speed and direction sensor Introduction During the measurement and detection process of the anemometer, in addition to the influence of the temperature, humidity and pressure environment conditions in the laboratory, many interference factors have not attracted the attention of the measurement workers. For example, the volume difference of the measured object will also cause detection. difference in results. This paper focuses on the influence of the volume of the measured object on the detection results of the anemometer in the wind tunnel.
2. Environmental conditions of the ultrasonic wind speed and direction sensor Most of the measurement institutions now use the Pitot tube micro-pressure sensor as the wind speed sensor standard. Standards with a detection accuracy grade better than 0.01. Most of the influence on the standard wind speed value is the change of the air temperature in the laboratory, so we carry out the verification when the temperature change in the laboratory does not exceed 3°C. The change of atmospheric pressure also has a great influence on the standard wind speed value, but the air pressure value in the laboratory is relatively stable, and the general laboratory can meet the change of air pressure. The change of air humidity has little influence on the standard wind speed value, and general laboratories can meet the requirements. Due to the difference in the sensor processing technology, the direction of the ultrasonic wind speed and direction sensor will have a certain impact on the measurement results, so the comparison should be performed in the same direction.
3. The influence of volume on wind speed measurement results 1. Ultrasonic wind speed and wind direction sensor testing According to the principle of wind volume conservation, the lower limit of wind tunnel wind speed measurement = 2B/A, where A and B are the cross-sectional areas of the wind tunnel where the tested instrument and pitot tube are located . In this paper, the tested instrument and the Pitot are at the same cross-sectional area, so the lower limit of measurement is 2m/s, A=B=0.5m*0.5m=0.25m2. There are many principles of anemometer, including thermal type, mechanical impeller type and ultrasonic type. Among them, the ultrasonic anemometer is a measuring instrument that uses the difference in propagation time of ultrasonic waves in the air to measure wind speed and wind direction. It has many characteristics that thermal and mechanical anemometers do not have. It is considered to be an ideal instrument to replace mechanical anemometers. It has the characteristics of convenient integration, low wear, long service life, and fast response.
