Thermographic Eddy Current Testing
Thermographic eddy current testing introduces high-frequency eddy currents into the workpiece and analyzes the resulting heat distribution with an infrared camera. Local temperature rises indicate discontinuities.
Physical-Chemical Mechanism of Action
High-frequency eddy currents generate electrical resistance through interaction with the metal's electrons. This leads to Joule heating, which is localized at contact points.
Metallurgical Relevance & Welding Risks
Thermographic eddy current testing can detect contact points and material defects in the material structure. However, incorrect settings or lack of calibration can lead to false results, causing inaccurate conclusions and potential misunderstandings in quality control.
Workshop Practice & Procedures
1. Make sure the workpiece is dry and free of surface conditions that could affect the infrared camera.
2. Use a high-frequency eddy current source with a frequency range of at least 10 kHz.
3. Analyze the infrared images for local temperature rises above the normal background.
4. Compare the results with reference images or standard specifications.