三线摆测量转动惯量方法的改进及不确定度分析

Improvement and Uncertainty Analysis of Tri-linear Pendulum Moment of Inertia of Rigid Methods

不确定度是评估测量结果准确性的重要参数。文中在测量刚体转动惯量的新方法"相对测量法"的基础上,给出其不确定度计算公式。新方法通过数学变换,省去了对上悬盘r及上下悬盘距离H的测量,可有效地减小误差。结果表明,公式改进后的计算结果较传统法相对误差降低0.84%,并且随着转角θ的增加,相对误差也随之增大,实验结果与理论分析一致。

Uncertainty is an important parameter to assess the accuracy of the measurement results. On the basis of the article ＂ relative measurement＂ of the new method of measuring rigid body moment of inertia,the formula of the uncertainty has been given. The new method through mathematical transform,eliminating the measurement of suspended plate r and the upper and lower hanging plate distance H,can significantly reduce the error. The results show that the relative error calculated by the improved formula is reduced by 0. 84% compared with the traditional method. Moreover,with the increase of the angle,the relative error increases,the experimental results are consistent with the theoretical analysis.