A Novel Quantitative Detection Model Based on Scanning Mode of Planar Double-Electrode Sensor

Planar capacitance detection is a novel non-destructive testing technology. The ill-posed nature of the inverse problem leads to less-than-ideal reconstructed image quality and detection accuracy. This paper proposed a novel quantitative scanning detection method based on the planar double-electrode capacitance sensor to circumvent the adverse effects of the inverse problem. The method established a mathematical model of the size of an anomaly inside the material and the length of the abrupt interval of the capacitance curve. Using finite element simulation and experiment, the optimal range of the distance between the sensor and the measured object and scanning step were then identified. The double-layer composite materials were used as the samples to measure the hole anomaly in its inner layer. The relative error is less than 1.4%, better than the imaging detection method. The rationality of the simulation conclusion and the correctness of the mathematical model are verified by experiments.