Eddy current inspection with stationary magnetic fields and scanning sensor arrays

摘要

Defects such as corrosion located on a covered metal component are detected through Eddy current inspection using stationary magnetic fields and scanning sensors arrays. A magnetizing yoke is held fixed to the cover of the component and a magnetic flux sensor is used to scan the area between the legs of the yoke over the cover of the component. Also, a fixed array of sensors can be provided between the legs of the yoke for automatic multiplexing of the sensors and sampling in sequence of signal responses picked up by sensors in the sensor array. Additionally, a stationary magnetic field arrangement is provided by a plurality of probes aligned adjacent and parallel with each other. A fixed array of magnetic flux sensors are arranged between the legs of the aligned probes for scanning for defects. This arrangement of fixed sesnsors can be used for underwater use and sealed by a sealing compound. An attachment means can be used for holding the arrangement stationary with respect to the surface of a submerged component during sampling of the signal responses.