A Novel GMR-Based Eddy Current Testing Platform

Detection and quantitative evaluation of deep defects in multi-layered structures is an essential task. Since electromagnetic sensor based on GMR effect is sensitive to the magnitude of the magnetic field, the GMR based EC probe can perform better than the conventional probe for low-frequency applications, i.e., when detecting defects deep buried in multilayered structures. A novel GMR-based eddy current testing platform for testing deep defects in multilayered conductive structures is presented. Firstly, the overall scheme and structure block diagram of the novel GMR-based eddy current testing platform are put forward. Then the paper focuses on analyzing and expounding the GMR effect and the key technique of design and development of GMR-based eddy current testing probe. Afterwards each function module and running process of hardware system and software system are introduced. It is able to fulfill the task of scanning inspection of deep defect in multilayered conductive structures.