减小低风速不确定度的研究

Research on reducing the uncertainty of low wind speed

风速计量检定装置的标准器普遍采用微差压计和皮托管,这种标准器的组合在低风速会产生较大的不确定度。实验表明,1和2m/s的扩展绝对不确定度分别为0.50、0.26m/s。低风速的扩展绝对不确定度大于最大允许误差的1/3,人们会质疑校准结果的可信度。通过分析风速表测量不确定度的主要分量,提出配套高精度微差压计和引入高精度热线风速计标准器,进一步减小低风速的不确定度。改进实验证明,1和2m/s的扩展绝对不确定度能够减小至0.13m/s,1m/s的扩展绝对不确定度减小了0.36m/s,2m/s的扩展绝对不确定度减小了0.13m/s。

The micro-differential pressure gauge and pitot tube are commonly used in the calibration device of wind speed measurement.The combination of these calibrators will produce greater uncertainty at low wind speed.Experiments show that the expanded absolute uncertainty of 1 and 2 m/s is 0.50 and 0.26 m/s respectively.The uncertainty of low wind speed expansion is absolutely greater than one third of the maximum allowable error,and the reliability of calibration results will be questioned.By analyzing the main components of measurement uncertainty of wind speed sensor,a high precision micro-differential pressure gauge and a high precision hot wire anemometer standard are proposed to further reduce the uncertainty of low wind speed.The improved experiment proves that the absolute uncertainty of 1 and 2 m/s can be reduced to about 0.13 m/s,the absolute uncertainty of 1 m/s is reduced by 0.36 m/s,and the absolute uncertainty of 2 m/s is reduced by 0.13 m/s.