Design And Research On Hot-film Wind Speed Measurement System

Wind is a natural phenomenon that exists everywhere in human daily life,and its speed is the distance that air flows in a unit of time.Nowadays,the commonly used wind speed measurement methods wind cup type,wind pressure type,hot-wire type and ultrasonic type.Among them,the hot-wire anemometer is widely used in the wind speed measurement in the pipeline due to its small size and fast response.In order to solve the problem that the hot wire anemometer is easy to break,this paper designed a hot-film wind speed measurement system based on the thermostatic difference circuit control using the FS5 thermal probe as the sensing probe,and the wind speed measurement system was developed with the data acquisition card and Lab View tool Software.In the small low-speed wind tunnel,the wind speed calibration test was carried out.In the temperature range of-10?30 ?,a total of 17 different central temperatures were selected at intervals of 2?3?.As the wind speed of the wind tunnel was 0.5?15 m/s,wind speed 0.5 m/s is taken as the calibration interval.Therefore,a total of 30 different central wind speeds are selected for the calibration test,and the influence of the ambient temperature on the thermal film measurement system is analyzed.Then,the power function is used to fit the results of the calibration test data.The temperature compensation for hot-film wind speed measurement system is achieved with three algorithms,namely multiple linear regression,CTA inverse function coefficient correction method and power function coefficient correction method.Through the error analysis,a good temperature compensation algorithm is obtained.The experimental analysis shows that the error between the measured wind speed value of the sensor and the standard wind speed value is basically within 4%after temperature compensation,which proves that the power function coefficient correction algorithm has a good temperature compensation effect on the sensor designed in this paper.