A high-Tc superconductive fluxgate magnetic sensor utilizing sintered YBa2Cu3O7-x core is constructed and applied to detect a flaw in an aluminum plate. The magnetic sensor successfully works in an unshielded environment. An electric current was supplied to an aluminum plate directly. A slit (0.2 mm width, 30 mm length), which is considered as a flaw, on an aluminum plate is successfully detected with this sensor, even though the slit is covered with another aluminum plate. The sensor can detect the flaw with its direction perpendicular to the electric current in the sample. It's supposed that the sensor can determine the length of the flaw larger than the diameter of the detection coil. These results suggest that the sensor has a potential for nondestructive evaluation of non-magnetic metals such as aluminum alloys, and also for their multi-layered structures.
(c)1999 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. IEEE Transactions on applied superconductivity , vol. 9, issue 2, 1999, pp. 3479-3482