Patent ID: 11435317

Abstract:
Eddy current sensing is governed by the diffusion equation of magnetoquasistatic fields. As such the eddy current sensor's proximity to the object to be inspected (i.e., “liftoff”) significantly affects the sensor's response signal. Methods and apparatus are disclosed for improving performance for an eddy current sensor, though they may also be used for other sensor types. These solutions are beneficial for both single channel eddy current sensors and arrays, and are particularly beneficial for measuring parts with complex surfaces. In some aspects improved performance is achieved by varying the stiffness of the mechanical support for the sensor. Some mechanical supports may exhibit anisotropic stiffness. After performing a scan with an eddy current array, a multi-channel shape filtering module is applied to improve defect detection. The module reduces the variability of defect response measured due to the unpredictability of the defect location transverse to the scan direction.