Principles of Eddy Current


Understanding Coils

A coil of copper wire is the common method of inducing eddy currents. Alternating current running through a coil creates magnetic fields in and around the coil. The magnetic fields form loops around the wire and join to form larger loops. If the current increases in one loop, the magnetic field will expand across some or all of the loops of wire that are in close proximity. This induces a voltage in the neighboring loops and causes electron flow, or eddy currents, in electrically conductive material. Any defect in the material including changes in wall thickness, cracks, pitting and other discontinuities, change the flow of eddy currents and are measurable on eddy current instruments. The enhanced eddy current systems offered by UniWest provide superb sensitivity with the clearest display for a wide range of applications.

Ohm’s Law

Ohm’s Law is one of the most basic formulas to determine electrical flow. The voltage, divided by resistance in Ohms, determines electrical current, in Amperes.