Research On The Field Calibration Of The Hot Air Anemometer For The Micro Wind Speed Jet Device

For a long time,hot-wire anemometer has been widely used in the measurement of wind speed,but its calibration method has not been improved and needs to be further improved.At present,the calibration method is limited to off-line calibration.Therefore,a portable calibration device is designed to achieve on-site calibration in order to obtain more extensive calibration methods.In this paper,the design and tracing study of the field calibration device for the fast air jet are carried out.A set of calibration devices for the fast jet of the wind speed is designed and established.The speed nozzle,the contraction nozzle and the various parts of the device are designed and the performance is optimized.The performance is analyzed.The compressed air with the highest pressure of 0.6MPa can flow through different sonic nozzles and can form different flow rates.Finally,seven steady flow points are realized in the calibration range of0.13m/s~1.43m/s.The uncertainty of the device is analyzed,and the expansion uncertainty of the device is when 1.43m/s,U_r=33.77mm/s,K=2.Finally,the field calibration of the micro wind speed of the hot wire anemometer was realized.The source process of the device is to calibrate the standard hotline through the primary level calibration device of the National Metrology Institute.The standard hotline is used as the transmission carrier to calibrate the designed device,and then the device is used to calibrate other hotline equipment to be calibrated.