| 摘要 |
PURPOSE:To detect flaws different in depth, by scanning a focus-type ultrasonic probe in the direction vertical to the surface of a material to be examined. CONSTITUTION:The center of an ultrasonic beam 2 emitted from a probe 1 in a position A crosses a surface 5a of the material to be examined in a position B, and the angle of incidence of this ultrasonic beam is (i), and the ultrasonic wave is refracted at an angle theta by the surface 5a of the material to be examined and enters into the material 5 to be examined, and the ultrasonic wave is focused in a position C. The probe 1 is raised to a position D which is higher than the position A by a length (h) in the direction vertical to the surface 5a of the material to be examined, and the beam from the probe 1 in the position D is focused at a point G. In this case, the point G is just above a focusing point G0 where the beam is focused when the material 5 to be examined does not exist. Therefoe, the focusing point is moved vertically from the point C to the point G according as the probe 1 is moved vertically from the point A to the point D. Thus, vertical face scanning is possible, and even flaws generated on a vertical plane are detected with a high precision. |
