Sensor for eddy current testing and method of use thereof

A method for detecting anomalies such as cracks at the edge of a specimen, comprising:

• a) providing an eddy current probe comprising a giant magnetoresistive sensor having a sensing plane and a sensing direction within said sensing plane, and a rotationally symmetric coil having an axis of symmetry, wherein said giant magnetoresistive sensor is centered at the axis of symmetry of the coil, with the sensing plane and sensing direction perpendicular to the axis of symmetry of the coil;
• b) orienting the sensitive plane of the giant magnetoresistive sensor parallel to the specimen surface;
• c) orienting the sensing direction of the sensor parallel to said edge of the specimen, so that the output signal is insensistive to said edge, but so that perturbations of eddy currents due to the presence of cracks at said edge are monitored by the probe;
• d) passing an alternating current through the coil placed adjacent to the specimen surface, said coil placed with its axis of symmetry perpendicular to the specimen surface, to induce circulating currents in the specimen surface plane;
• and
• e) utilizing said probe to scan the surface in a region including said edge to produce an output signal that enables detection of said anomalies.