| 摘要 |
PURPOSE:To measure, with excellent sensitivity, an item to be inspected which has a curvature, by employing a movable core as the core of an electromagnet which applies a magnetic field to the item to be inspected. CONSTITUTION:An electromagnet core outer pole 1B is adapted to be vertically movable, and the end of the outer pole 1B has a curvature. Accordingly, it is possible to provide the measuring apparatus without producing any air gap between the core outer pole 1B and an item 6 to be inspected. A magnetic field is applied to the item 6 by exciting a coil 2. A force according to the Fleming's rule is applied to the item 6 by the applied magnetic field and an eddy current generated in the item 6 by exciting a transmission-reception coil 3 with a pulse current, thus causing an ultrasonic wave to be generated. In the case of reception, a voltage is generated in the trasmission-reception coil 3 by the mechanism reverse to that in the case of transmission. |
