Method for detecting flaws in a steam generator tube using a flexible eddy current probe having coil bank switching

摘要

A method and apparatus for inspecting the profile of the inner wall of a conduit, such as a heat exchanger in a steam generator by a probe body that includes eddy current sensing coils. The number of eddy current sensing coils is increased for more completely sensing the conduit surface without a corresponding increase in coaxial cables by the use of a bank switch which switches respective banks of coils to existing conduits.