基于GUM的叶轮数字风速仪不确定度分析与评定

Uncertainty analysis and evaluation of impeller digital anemometer based on GUM

叶轮数字风速仪目前没有检定规程,需要采用高一级标准进行校准,才能确保使用中测量数据的准确、可靠,为了表征校准结果的可信赖程度,基于GUM法分析并评定叶轮数字风速仪的测量不确定。首先依据测量数学模型制定测量方案,选取2、5、10、15、20m/s校准点对AM-4202型叶轮风速仪进行10次重复性校准,然后采用GUM法分析校准过程中不确定度的来源,选取合理的概率分布计算不确定度分量,最后计算得到扩展不确定。结果表明,除了重复性引入的不确定度,测量环境、标准皮托管的等级、安装时与气流方向的夹角、数字压力计的等级、风洞本身的性能以及数据修约都会影响测量结果的不确定度,在计算合成标准不确定时应全部考虑,以确保测量结果更加准确、可靠。

At present,there is no verification regulations for the impeller digital anemometer,which needs to be calibrated by a higher standard to ensure the accuracy and reliability of measurement data in use.In order to characterize the reliability of calibration results,the uncertainty of measurement of impeller digital anemometer is analyzed and evaluated based on the GUM(guide to the expression of uncertainty in measurement)method.Firstly,the measurement scheme is made according to the mathematical model of measurement and the AM-4202 impeller anemometer is calibrated 10 times repeatedly at 2,5,10,15 and 20 m/s calibration points.Then,the sources of uncertainty in the calibration process are analyzed on the basis of GUM method,and the specific value of uncertainty component is calculated by using a reasonable probability distribution.Finally,the expanded uncertainty is obtained.The results show that in addition to the uncertainty introduced by repetitiveness,the measurement environment,the level of the standard pitot static tube,the angle between the installation and the airflow direction,the level of digital manometer,the performance of wind tunnel,and the rounding rules will affect the uncertainty of measurement results.All these factors should be considered when calculating the composite standard uncertainty to ensure more accurate and reliable measurement results.