皮托管-微压计原理的风速计检定装置不确定度评估及其特征分析

Evaluation and Characteristic Analysis of the Uncertainty of Anemometer Verification Device Based on Pitot Tube and Micro Manometer

常见的风速计检定装置由风洞和皮托管-微压计风速标准器两部分组成,前者受工作段气流均匀性、稳定性影响,后者受温度、湿度、大气压和皮托管系数、微压计不确定度的影响,其中由于温度、湿度、大气压引入的不确定度数值小,可忽略不计。随着风速的增大,风速计检定装置不确定度呈现先减小后增大的规律,在9.1m/s时达到最小;而检定装置的相对不确定度在快速下降后,逐渐减小,逐渐趋近于常数。在低风速段(<10m/s),微压计引入的不确定度较显著;在高风速段,风洞工作段的不稳定性和不均匀性引入的不确定度较显著。

Anemometer verification device usually consists of two parts:wind tunnel and pitot tube-micro pressure anemometer.The former is affected by the air flow uniformity and stability of the working section,while the latter is affected by temperature,humidity,atmospheric pressure,pitot tube coefficient and the uncertainty of the micro pressure meter.Because the uncertainty value introduced by temperature,humidity and atmospheric pressure is small,it can be ignored.With the increase of wind speed,the uncertainty of the anemometer calibration device decreases first and then increases,reaching the minimum at 9.1 m/s;while the relative uncertainty of the calibration device decreases rapidly,and then decreases gradually approaching to constant.In the low wind speed segment(<10 m/s),the uncertainty introduced by the micro manometer is significant;in the high wind speed segment,the uncertainty introduced by the instability and non-uniformity of the wind tunnel working segment is significant.