| 摘要 |
PURPOSE:To apply detection to a container, tubular object to be inspected, etc., by providing a magnetizing coil by which a magnetic flux is generated in an object to be inspected in the vicinity of the surface irradiated with a laser beam and a detecting coil to detect a current generated by an echo signal coming from the object. CONSTITUTION:When a defect 5 is existed in the object 3, an ultrasonic wave beam 4 is partly reflected and returned as the echo signal 6 to the surface of the object 3. The magnetizing coil 7 is arranged over the surface of the object 3, and the generated magnetic flux 8 is existed around the surface of the object 3. Therefore, the current 10 is made to flow in the neighbourhood of the crossing pint of the echo signal 6 and the magnetic flux 8, while intersecting orthogonally with both of them. The magnetic flux is generated around the place where the current 10 is made to flow, and an induced voltage is generated in the detecting coil 8 due to the magnetic flux is crossed with the detecting coil 9, then by means of detecting this voltage, the echo signal 8 corresponding to the induced voltage can be detected. The detection is thereby applicable for the container and the tubular object to be inspected. |
