| 摘要 |
PURPOSE:To prevent the decrease in sensitivity and to make the flaw detection over a wide range at one time possible by disposing a conductive rod body on the inside wall of a signal converting coil, placing a part thereof in proximity to a material to be inspected and detecting the state of electromagnetic coupling thereof to the material to be inspected. CONSTITUTION:A conductive rod body (collector) 2 is disposed on the inside of a signal converting coil 1. An impeader 3 is brought in proximity to the collector 2 by a method of conducting the impeader 3 to the outside part of the colllector 2 or a method of forming the collector 2 in such a way that a material 4 to be inspected in passed through the collector 2. When the impeader 3 and the material 4 are disposed relatively in such a state, the state of electromagnetic coupling of the impeader 3 and the material 4 changes when a defect exists in the material 4 and comes right under the impeader 3. If said state is detected, the degradation in sensitivity is prevented and the flaw detection over a wide range at one time is made possible. |
