A PCA and ELM Based Adaptive Method for Channel Equalization in MFL Inspection

Table 1

SD of raw data and corrected data.

Index of flaw	SD of raw data	SD of median corrected data	SD of baseline estimation equalized data	SD of adaptive channel equalized data	flaw size (length width depth, unit mm)
1	0.0544	0.0129	0.0121	0.0093	40 × 20 × 1
2	0.0548	0.0138	0.0136	0.0108	6 perforation
3	0.0565	0.0175	0.0169	0.0158	8 perforation
4	0.0617	0.0324	0.0318	0.0288	20 × 40 × 4
5	0.0564	0.0182	0.0179	0.0160	40 × 20 × 4
6	0.0560	0.0143	0.0143	0.0142	20 × 20 × 2
7	0.0544	0.0115	0.0104	0.0089	40 × 20 × 2
8	0.0573	0.0174	0.0163	0.0141	20 × 40 × 2