Eddy Current Frequency Sweeping
Eddy current free-frequency analysis is an electromagnetic testing technique that achieves different penetration depths in the material by varying the excitation frequency, to analyze near-surface properties and material separations. It is used for coating thickness measurement and flaw detection.
Physical-Chemical Mechanism of Action
Eddy current swept frequency analysis uses electromagnetic fields generated by an eddy current. By varying the frequency of the exciter, the penetration depth of the magnetic field into the material changes. This change in depth allows different layers or material zones in the workpiece to be examined.
Metallurgical Relevance & Welding Risks
This analysis is especially important for checking weld quality and integrity. It can detect porosities, cracks, or lack of fusion that can result from inadequate welding. Incorrect interpretation of the results leads to false positive or negative test results and can therefore be dangerous.
Workshop Practice & Procedures
To perform eddy current swept frequency analysis correctly, the exciter voltage range must be carefully set. A frequency from 10 kHz to 2 MHz is typically used. The measurement should be done in a quiet environment to minimize interference fields. Always compare the results with the specific material properties and the application area.