In which scenario is Eddy Current Testing preferred over ultrasonic testing?

Eddy Current Testing (ET) is particularly effective for inspecting surface flaws in thin, conductive materials due to the method's ability to detect small discontinuities and variations in electrical conductivity. When the material is thin, the eddy currents induced by the testing probe are concentrated near the surface, making it ideal for identifying surface-breaking defects such as cracks, pits, or inclusions.

In contrast, ultrasonic testing might be more suitable for thicker materials where it can investigate deeper into the material for subsurface flaws, but it is less sensitive to surface-breaking defects compared to ET. Additionally, in cases where mechanical properties are being assessed, non-conductive materials cannot be tested using ET, as the method relies on the conductivity of the material to generate the eddy currents. Therefore, ET excels in scenarios that involve thin, conductive materials, where the surface condition is critical.