H
L
Defect
frequency
Encircling
coil
Segment
coil
E coil
Defect
frequency
Encircling
coil
Segment
coil
E coil
Low pass filter
High pass filter
Switch
F
2
4860
2100
3499
6999
486
210
350
700
F
3
4880
2108
3513
7027
488
211
352
702
F
4
4900
2117
3528
7056
490
212
353
705
F
5
4920
2126
3542
7085
492
212
355
708
F
6
4940
2134
3556
7114
494
213
356
711
F
7
4960
2143
3571
7143
496
214
357
714
F
8
4980
2152
3585
7171
498
215
359
717
F
9
5000
2160
3600
7200
500
216
360
720
F
A
5020
2169
3614
7229
502
217
362
723
F
B
5040
2177
3628
7258
504
218
363
725
F
C
5060
2186
3643
7287
506
218
365
728
F
D
5080
2195
3657
7315
508
219
366
731
F
E
5100
2203
3672
7344
510
220
368
734
F
F
5120
2212
3686
7373
512
221
369
737
EDDYSENSOR Operating Manual
Filter settings 6