| 摘要 |
PURPOSE: An apparatus for detecting a defect in a steel sheet is provided to detect the size of residual magnetization in the steel sheet, thereby detecting the defect generated in the longitudinal direction of the steel sheet. CONSTITUTION: An apparatus for detecting a defect in a steel sheet (1) includes a magnetizer (10) and a sensor device (30). The magnetizer magnetizes the steel sheet. The sensor device detects residual magnetization which remains in the steel sheet by the magnetizer. The sensor device detects the defect in the steel sheet with detecting the variation of the residual magnetization. The apparatus further includes a demagnetizer (50) for removing the residual magnetization from the steel sheet. |
