Patent ID: 9222917
Filing Date: 2015-12-29
Classification: G01N,Y10T

Abstract:
1. An eddy current probe for detecting a defect in a test object, the eddy current probe comprising: a first coil and a second coil both electrically connected to a first voltage terminal, the first voltage terminal being configured to receive a drive voltage, wherein the first coil and the second coil are drive coils; and a third coil and a fourth coil both electrically connected to a second voltage terminal, the second voltage terminal being configured to be coupled to a ground, wherein the third coil and the fourth coil are receive coils, and wherein the first coil is electrically connected to the third coil at a first bridge terminal, the second coil is electrically connected to the fourth coil at a second bridge terminal, the first coil is wound over the third coil, and wherein the first, second, third, and fourth coils are configured to indicate the defect in the test object by a voltage difference between the first and second bridge terminals when the four coils of the probe are inside the test object, wherein the first coil, second coil, third coil, and fourth coil are each located solely within the eddy current probe.