Table 4.
Compensation techniques used in eddy current testing.
| Ref. | Research Area | Compensation Techniques |
|---|---|---|
| [85] | To remove the lift-off effect in PEC ferromagnetic material test piece inspection | Relative magnetic flux changing rate |
| [86] | Presented a simple model for metal thickness measurement that unaffected by lift-off effect. | Signal analysis base on multi-frequency phase signature |
| [87] | Developed ECT system based on three coils exciting coils to measure the plate thickness | Data analysis using peak frequencies of the sensor signal to estimate the thickness of the plate |
| [88] | Proposed a method for suppressing of lift-off effect in SMFM system | Signal deconvolution |
| [89] | Proposed ECT system with rectangular sensor configuration and time domain analysis and frequency domain analysis for defect classification. | Time domain analysis and frequency domain analysis |
| [90] | Proposed a method to reduce the lift-off effect in PEC deep defect measurement | Measure the defect dimension base on slope of the linear curve of the peak value difference sensor signal |
| [91] | Investigate the lift-off effect in the normalized impedance plane | Hough transform |
| [92] | Developed PECT system for ferromagnetic material electrical conductivity measurement | Mathematical model |
| [89] | Investigated the feature extraction techniques for PEC defect classification | Signal differential analysis |
| [93] | Developed ECT system to measure the thickness of nickel layer | 3-D edge-based hexahedral nonlinear FEM |
| [79] | Investigated the effect of lift –off in PEC non-destructive testing | Normalization and two-stage operative process |
| [94] | Construct a system to measure the thickness of metal plates | Lift-off points of interception |