METHOD AND APPARATUS FOR THE DETECTION OF ANOMALIES IN ROTATING MEMBERS

摘要

A current carrying coil placed near to a rotating electrically conductive member induces eddy currents in it, and a sensing or pick- up coil in the vicinity of the eddy currents will have a voltage generated in it indicative of the eddy currents. The magnitude of the latter and the voltage generated in the sensing or pick-up coil will be reduced at those points where cracks or flaws occur, providing such defects influence the resistance to the flow of current within a part of the rotating member.