Fig. 1.
Fig. 2.
Fig. 3.
Experimental data of the test specimen investigation_
| No. of defect | The number of holes n (length in mm) | Signal amplitude from the defect (V) | ||
|---|---|---|---|---|
| 80 kHz | 160 kHz | 320 kHz | ||
| 1 | 9 (2.9) | 4.6 | 10.6 | 10.6 |
| 2 | 7 (1.7) | 2.7 | 7.9 | 7.9 |
| 3 | 19 (2.9) | 5.7 | 10.7 | 10.8 |
| 4 | 37 (4.1) | 7.5 | 10.9 | 10.9 |
| 5 | 1 (0.5) | - | 1.1 | 1.6 |
| 6 | 3 (1.1) | 1.0 | 2.7 | 4.3 |
| 7 | 5 (1.7) | 2.0 | 6.2 | 10.3 |
| 8 | 7 (2.3) | 3.4 | 8.3 | 10.5 |