| 摘要 |
An ultrasonic inspection apparatus for the inspection of underwater structures consisting of means for scanning a beam of ultrasound over the surface of the structure at a predetermined angle of incidence, means for receiving and displaying echo signals from the structure indicative of discontinuities within the structure, the action of the display means being initiated by control signals derived from echo signals returning from the surface of the structure, thereby rendering the displayed signals independent of the separation between the scanning means and the surface of the structure. |
