Flaw detector

Abstract

Abstract PURPOSE: To inspect a flaw rapidly with high sensitivity and high precision by detecting variation in magnetic characteristics appearing at a defect part by supplying magnetic flux to a member to be flaw-detected by a permanent magnet. CONSTITUTION: In the center of permanent magnet 1, detection coils 2 and 3 are provided at a fixed interval and those detection coils 2 and 3 are added to a flaw detecting device not shown in the figure. A sensor constituted in this way is inserted into steel tube body 6, for example, which is an object to be flaw-detected. Tube body 6 is magnetized by magnet 1 and magnetic flux penetrates thickness part 6b of tube body 6. When thickness part 6b has no defect, the permeability of thickness part 6b is constant and when not, it changes a defect part 7. Therefore, this variation is detected by detection coils 2 and 3, so that the defect of a steel material can be detected with extremely high sensitivity and high precision. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Takeo Tezuka
• 👤 Chikara Inoue

Bibliographic Details