Eddy Current Differential Coil Technique
Eddy current differential coil technology is a testing method with two oppositely wound coils that suppresses interfering signals and highlights local inhomogeneities. It is used for crack-free inspection of pipes and wires.
Physical-Chemical Mechanism of Action
This technique uses two coils wired in opposition. A current flow in one coil induces a magnetic field that is back-induced through the other coil. The difference between the two signals highlights local inhomogeneities in the material.
Metallurgical Relevance & Welding Risks
This technique is especially useful for inspecting pipes and wires for cracks or inhomogeneities. Incorrect settings can lead to missed detections, posing risks in material use.
Workshop Practice & Action Instructions
For effective use, the coils must be properly aligned and calibrated. The voltage should be set to suppress noise and sharply highlight inhomogeneities. Regular calibration of the equipment is essential.