微小角度测量装置不确定度分析及实验研究

Uncertainty Analysis and Experimental Study of Micro-angle Measuring Device

为了准确获得基于法布里-珀罗(F-P)标准具的微小角度测量装置的测量精度,采用测量不确定度评定指南法(GUM)和蒙特卡洛法(MCM)分别进行角度测量不确定度研究。建立了GUM不确定度评定模型和MCM不确定度评定数学模型,采用正反转测角差法调整反射镜初始位置,完成了150″的角度测量重复性实验,获得了不同评定方法下的测量不确定度。评定结果显示,在150″测量范围内,GUM不确定度评定结果为0.0375″,MCM不确定度评定结果为0.0400″,在给定的0.0005″允差范围内,GUM未通过MCM验证,在当前及类似应用场景下应当采用MCM进行不确定度评定。通过正态概率图法对被测角度进行正态分布检验,2种评定方法测量不确定度结果不一致是由被测角度的分布函数偏离正态分布引起的。

In order to improve the measuring accuracy of the micro-angle measuring device based on Fabry-Perot(F-P)etalon,two methods of guiding by the expression of measurement(GUM)and Monte Carlo method(MCM)were used to study the measuring uncertainty,respectively.GUM uncertainty evaluation model and MCM mathematical model were established.The initial position of the mirror was adjusted by the angle difference measurement method,and 150″measurement repeatability experiment was completed to obtain the measurement uncertainty of different evaluation methods.The evaluation results show that the uncertainty evaluation result of GUM is 0.0375″and MCM is 0.0400″within the 150″measurement range.Within the given tolerance range of 0.0005″,GUM is not verified by MCM,so MCM should be used to evaluate the measurement uncertainty in current and similar application scenarios.The normal probability plot method is used to test the normal distribution of the measured angle.It is found that the inconsistent results of the two evaluation methods are due to the deviation of the measured distribution function from the normal distribution.