Principal Component Analysis of Pulsed Eddy Current Response From Corrosion in Mild Steel

Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review

“…A coil will capture the time-derivative of the magnetic field while a magnetic sensor will sense the field itself. PEC time responses can be normalized in order to reduce the effects of lift-off variation and varying magnetic permeabilities prior to the calculation of the above timedomain features [48]. Fig.…”

“…9 shows typical examples PEC signals obtained by using a Hall-device. The features that are used to infer the desired parameters may be readily available, such as peak value [32], [48], [49], peak arrival time [49], rising time [50] and zero crossing time [51]. In addition to these more traditional features, there have also been emerging features proposed in various reports, such as the so called ''relative variation of magnetic flux'' [20], which has been shown through both simulation and experiments to have potentials in determining the lift-off for ferromagnetic materials [7].…”

“…Other examples of work where PCA has been used are introduced in Refs. [14], [28], [48], [52], [55][56][57][58][59][60].…”

“…Other examples of defect detection and characterization include flaws in the inner surface of pipe under insulation [87], outer corrosion on carbon steel pipes used in oil and gas industry [35], surface and sub-surface cracks and cavity detection in con-casting slabs (CCS) [56], subsurface corrosion in a plate [4], surface corrosion on coated mild steel S275 plates [48], [88], and various types of defect on steam generator support structures [59]. Detection of wall thinning in pipe structures has been included in the previous sub-section above.…”

Identification and characterisation of steel corrosion using passive high frequency RFID sensors

“…Eddy current was proposed for corrosion detection and structural health monitoring (SHM) [12][13][14]. Pulsed Eddy Current (PEC) [15][16][17][18] and eddy current pulsed thermography (ECPT) [19][20][21] have demonstrated its detection capabilities in corrosion characterisation. PEC can be automated and it is under a moderate cost.…”