Crack detection and recognition using an eddy current differential probe

A new differential eddy current testing sensor used for detecting crack extension direction

“…In order to reduce the various influences caused by the factors such as environmental noise, temperature, and lift-off, the ECT probes are usually made as the differential probes [21][22][23][24]. Furthermore, the differential structure can reduce the nonlinear items in test results and improve the linearity of outputs, which can make the inverse quantitative evaluation easier to realise.…”

Natural crack recognition using inverse neural model and multi-frequency eddy current method

“…The "Multi-Frequency Excitation and Spectrogram" (MFES) system [3] was used to achieve input data for a flaw recognition procedure. A basic idea behind the MFES method is to use a complex signal containing selected harmonic components as an exciting signal and a spectrogram to precise crack characterization.…”

Study of pulse eddy current probes detecting cracks extending in all directions

“…Rose et al [7] described the defect detection in time-domain for both air-core and ferrite-core PEC probes with one plat coil. Chady and Enokizono [8] proposed a differential probe and a system for the testing of conducting materials, then precise crack imaging was achieved with the application of a neutral network. Differential probes are also broadly employed in the PEC testing, however, it fails to detect cracks in all directions, especially to long cracks.…”