To overcome the large error caused by traditional ETC non-destructive detection, a novel method based on directly analysing the normalized capacitance value was proposed by using the finite element method described in the present study. In this article, the correlation between the normalized capacitance value and the measured object (the defect) size was summarized, and the influence of the geometric parameters of the two-electrode planar capacitive sensor on the detection result was discussed. The results of this study show that this method is suitable for detecting an object with a size larger than or equal to the gap between the two plates. Under this condition, the number of special points corresponding to the object has a linear relationship with the object size. As an important parameter, the gap size between two polar plates can determine the minimum size of the detected defect, and the step size of the scanning during the measurement is another important parameter, which can determine the detection accuracy. The new detection method proposed in this study is expected to provide a new idea for the optimization of the performance of non-destructive detection technology based on a parallel plate capacitor array.

为了克服传统ETC无损检测带来的较大误差，提出了一种使用本研究中描述的有限元方法直接分析归一化电容值的新方法。本文总结了归一化电容值与被测物体（缺陷）尺寸的相关性，并讨论了两电极平面电容传感器的几何参数对检测结果的影响。这项研究的结果表明，该方法适用于检测尺寸大于或等于两个板之间间隙的物体。在这种情况下，与对象相对应的特殊点的数量与对象大小呈线性关系。作为重要参数 两个极板之间的间隙尺寸可以确定检测到的缺陷的最小尺寸，而测量过程中扫描的步长是另一个重要参数，可以确定检测精度。这项研究中提出的新的检测方法有望为优化基于平行板电容器阵列的无损检测技术的性能提供一个新思路。