• Industrial X-Ray and Allied Radiographers (I) Private Limited

Eddy Current Testing of Heat Exchanger Tubes

Eddy current inspection is one of several NDT methods that use the principal of 'electromagnetism' as the basis for conducting examinations. Eddy current remote field testing is possible for installed or loose heat exchanger tubes. Eddy currents are created through a process called electromagnetic induction. When alternating current is applied to the conductor, such as copper wire, a magnetic field develops in and around the conductor. This magnetic field expands as the alternating current rises to maximum and collapses as the current is reduced to zero. If another electrical conductor is brought into the close proximity to this changing magnetic field, current will be induced in this second conductor. Eddy currents are induced electrical currents that flow in a circular path. They get their name from "eddies" that are formed when a liquid or gas flows in a circular around obstacles when conditions are right.