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EDDY CURRENT INSPECTION
Eddy Current Inspection (ET) is one of the
most widely applicable of the Non-Destructive
Inspection methods. It depends on measuring the
changes in the impedance of a coil due to change in
the flow of eddy current in a conductor. Any
material change that affects the flow of the
induced eddy current sufficiently can be detected.
Because so many things affect the flow, eddy
current inspection can be ap plied
to a wide variety of test situations. Principle
areas of application are flaw detection,
material-thickness measurements, alloy sorting and
the monitoring of metallurgical conditions such as
hardness and heat treatment. Besides its
versatility, the major advantages of eddy current
inspection are the speed at which tests can be
performed and its ability to inspect through
painted coatings. It can be used also to inspect
both ferromagnetic and non-magnetic materials. The
principle disadvantages of the method is its
limited depth of inspection into the material or
part being inspected.
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