交流增益的测量不确定度

The Uncertainty of the Measurement of AC Gain

介绍了用四参数正弦波最小二乘拟合法评价线性测量系统交流增益的不确定度分析和评价过程。讨论了主要的不确定度来源,包括信号源误差、采集序列的谐波失真、采集序列的噪声及非谐波失真、采集序列中信号周期的抖动、软件拟合运算误差的影响等等,给出了减小不确定度的主要措施。并结合一个实例,给出了评价结果。

The uncertainty of evaluation results of AC gain of linear measuring system by the least mean square four-parameter sine wave curve-fit method, including the courses of analysis and evaluation of uncertainty is described. Some error sources of AC gain evaluation are discussed, including the signal amplitude errors, the harmonic distortion of sampling serials, the quantization errors and noise and the spurious distortion, the jitter of the signal periods in sampling serials, the calculation errors of software, and so on. The uncertainty of AC gain of linear measuring systems is given, and several main methods about decreasing the AC gain evaluation errors and evaluation uncertainty have been proposed. In an example of experiment, the analysis and uncertainty evaluation results of AC gain by this method is presented.