钟罩装置标准容积的数学模型研究与建立

在钟罩装置标准容积实测数据的基础上,通过描点图定性分析了钟罩罩体高度和半径的关系特性,提出采用傅里叶级数建立数学模型,借助Matlab获得理想的函数方程,并分析了其拟合标准差。实际应用中采用光栅尺测量钟罩下降的高度,运用定积分原理对函数进行积分获得钟罩下降任意高度时排出的气体容积值,在瞬时流量下限标准容积的相对扩展不确定度达到4×10^-4(k=2),相对以半径平均值为估计值的方法,降低了66.7%,同时可实现钟罩在检测过程中任意点的启停。

Study and Establishment of the Mathematical Model of the Standard Volume of the Bell Prover

The characteristic of bell prover’s height and radius is qualitatively analyzed by the dot diagram based on the measured datas, the establishment of mathematical model by Fourier series is proposed, the ideal function is obtained by using Matlab and the fitting standard deviation is analyzed. In practical application, the descending height of the bell prover is measured by grating rulers, the function is integrated by using principle of definite integral to obtain the volume value of the gas discharged by the bell prover, at the bottom of the instantaneous flow, the expansion uncertainty of the standard volume is 4×10-4(k=2), which decreases by 66.7 % relative to the method of estimation based on mean radius, simultaneously, starting and stopping at any point of the bell prover during the test is implemented.