How does Eddy Current Weld Inspection Work?

The eddy current weld testing process relies on the material characteristic called electromagnetic induction. When an alternating current passes through the conductor (such as the copper coil), there will be an alternating current magnetic field around the coil, and with the rise and fall of the alternating current, the magnetic field will extend and contract. If the coil is then brought close to another electrical conductor, the fluctuating magnetic field around the coil will penetrate into the material, and according to Lenz's law, there will be eddy currents flowing in the conductor.
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