GB/T 33693-2017 in English

National Standard of the People's Republic of China GB/T 33693—2017: Test Method of Ultrasonic Anemometer

Background of Standard Formulation and Analysis of Technical Evolution

This standard was drafted in accordance with the rules given in GB/T1.1-2009 and is managed by the National Technical Committee for Standardization of Meteorological Instruments and Observation Methods. The main drafting units of this standard include the Meteorological Observation Center of the China Meteorological Administration and the Xinjiang Meteorological Technology and Equipment Support Center.

Comparison of Standard Frameworks

Explanation of professional terms and practical application cases

Ultrasonic anemometer:It is made based on the principle that the propagation speed of ultrasonic waves in the air changes with the wind speed. Its core is to calculate the wind speed and wind direction using the time difference or phase difference of ultrasonic signals.

Blockage ratio:It refers to the ratio of the windward area of the instrument in the wind tunnel test section to the cross-sectional area of the test section, which directly affects the uniformity and stability of the wind flow field. The standard requires that the blockage ratio should not be greater than 0.05 to ensure the accuracy of the test results.

Test conditions and equipment requirements

Laboratory environment: The temperature is controlled at $15^{\circ}C \sim 30^{\circ}C$, the relative humidity is not more than 85%, and the atmospheric pressure range is $500 hPa \sim 1060 hPa$.

Implementation suggestions and precautions

1. Before testing, ensure that all standard instruments are calibrated and within the validity period.

2. Laboratory environmental conditions should be strictly controlled within the standard range, especially changes in temperature and humidity may affect the measurement results.

3. When installing the ultrasonic anemometer, pay attention to its relative position with the pitot-static tube to ensure that there is no mutual interference.

4. The selection of wind speed and wind direction test points should be determined according to actual needs, but must cover the minimum requirements specified in the standard.