| 摘要 |
PURPOSE:To simplify a device and to improve sensitivity, by a method wherein a magnetizer, which generates a magnetic field, rotating in a flat manner, on a surface part of a material to be detected by means of a symmetrical polyphase alternating current, and a magnetic detector employing a thin film search coil are aligned so as to cover a total surface in a peripheral direction of a material to be detected. CONSTITUTION:In a magnetic flaw detector, a magnetizer, which generates a magnetic field, rotating in a flat manner, on a surface layer of a material 1 to be detected by means of a symmetrical polyphase alternating current, and a magnetic detector employing a thin film search coil 7 are aligned so as to cover the whole surface in a peripheral direction of the material 1 to be detected. This eliminates rotary driving of the material to be detected, permits detecting of all flaws in all directions over the whole periphery and length of the material merely through the relative movement of the material to be detected to a magnetizer (that which is monolithically unitd with a detector), which results in enabling to provide a simple structure, high-sensitive, and convenient device. |
