| 摘要 |
PCT No. PCT/JP87/00789 Sec. 371 Date Jun. 20, 1988 Sec. 102(e) Date Jun. 20, 1988 PCT Filed Oct. 16, 1987 PCT Pub. No. WO88/02857 PCT Pub. Date Apr. 21, 1988.A method and an apparatus for detecting defects in the surface of a metal material relying upon the potential drop method. Namely, a method of precisely determining the shape of crack from a distribution of potential differences in the vicinity of crack by arranging power supplying electrodes and measuring electrodes on the surface of the metal material in the form of a matrix, and switching the electrodes that supply electric current and the electrodes that measure potential differences to measure distributions of potential differences in many directions, and an apparatus for detecting surface defects relying upon the potential drop method. In the apparatus for detecting surface defects, the arrangement of power supplying electrodes and supply currents are optimized to precisely detect the shape of crack in the surface.
|
