Patent ID: 8264221

Claim:
An eddy current probe assembly configured to perform an inspection on a test object with longitudinal shape, being passed through the assembly in the object's axial direction during an inspection session, the probe assembly comprising a first plurality of probe modules being disposed in a first radial plane and with the modules arranged circumferentially relative to each other and forming an iris structure encircling an inspection zone, wherein a movement of each of the probe modules closer to or further away from the center of the inspection zone makes the inspection zone enlarged or contracted; wherein each probe module comprises a plurality of eddy current sensing elements which are disposed at a corresponding sensing surface of each of the first plurality of probe modules facing the inspection zone; wherein the sensing surfaces of all of the probe modules collectively substantially cover the entire circumference of the test object, wherein a second plurality of the probe modules is disposed in a second radial plane substantially next to the first radial plane, and each of the second plurality of the probe modules comprising a plurality of eddy current sensing elements disposed substantially at a sensing surface of each of the second plurality of probe modules facing the inspection zone, and, the sensing surface of the second plurality of probe modules is offset circumferentially from the sensing surface of the first plurality of probe modules so that the circumference of the test object is sufficiently covered by the sensing surfaces.