What are the instruments and methods for measuring wind speed in air conditioning system?

In air conditioning and ventilation system, wind speed is a basic parameter, and the size of air volume can generally be calculated by the measured average wind speed. In the air supply system of central air conditioning, it is necessary to leave a measuring hole in the main air duct, and prepare to measure the flow velocity in the air duct with a piezometer. Commonly used measuring instruments are: (1) mechanical anemometer: mechanical anemometer is a traditional wind speed measuring instrument commonly used in the past, which mainly uses the dynamic pressure of airflow to push the mechanical device to display the flow speed, and can be divided into airfoil anemometer and cup anemometer. When in use, all impellers must be placed in the airflow. Generally, the wind speed is measured within the time range of 0.5~ 1min, and the read wind speed is the average value of the flow velocity. (2) Thermistor constant temperature anemometer: It is mainly composed of measuring rod with thermistor probe, wires and electrical instrument components. When measuring speed, the thermal probe is placed in the airflow, and the wind speed at this point can be quickly and sensitively reflected by adjusting the instrument. Because the probe is small, it has high sensitivity and accurate speed measurement.