化学测量中不确定度的计算方法——不确定度连续传递模型计算示例

不确定度连续传递模型的基本步骤为：①对标准曲线的各点进行不确定度评定，给出各点的标准不确定度；②对标准曲线各点的响应值进行多次测定，得出其平均值和标准不确定度；③以这2个标准不确定度为权重进行拟合，得出双误差拟合方程和标准不确定度的计算公式；④计算标准曲线各点与其校准点的差值，并将其转换成标准不确定度；⑤将以上4项按不确定度传播规律计算总不确定度。实际测量时， ①、②、④步用插值法算得。通过一个实例比较了不同拟合方法间结果的差别，说明了运用X、Y的相对误差作为权重的直线拟和，再加上“不确定度连续传递模型”算得的测量不确定度更为合理。

Uncertainty calculation method in chemical measurement-calculating example of Continuous Propagation Model of Uncertainty

Basic steps of Continuous Propagation Model of Uncertainty are as follows:firstly, evaluate the uncertainty of standard series and obtain the standard uncertainty;secondly,determine the response value of standard series time again and calculate the mean and standard uncertainty; thirdly, fit the standard curve by double errors regression and obtain the double-errors fitting equation along with calculation equation of standard uncertainty;and then calculate the different values between standard points and calibration points,moreover, convert it into the standard uncertainty;finally, total uncertainty of all above are calculated by the rule of uncertainty propagation. The 1, 2, 4 steps are calculated by interpolation in actual measurement. Furthermore ,calculation results by different fitting methods are compared and proved the measurement uncertainty that calculated by the model is more reasonable.