What is one limitation of Eddy Current Testing?

One significant limitation of Eddy Current Testing is its effectiveness at detecting defects. This method primarily relies on the generation of electrical currents in conductive materials, which can only penetrate to a shallow depth. As a result, it is generally ineffective for locating defects that are deeper than a few millimeters within the material. This limitation is crucial, especially when assessing components that may have internal flaws below the surface level, where other testing methods with better penetration capabilities might be necessary.

Additionally, while the other options highlight valid concerns associated with Eddy Current Testing—such as the requirement for specialized knowledge and potential slower inspection times—these factors do not directly relate to the specific depth limitations that define the method's effectiveness in detecting subsurface defects. Hence, the inherent limitation regarding depth is particularly relevant in many practical applications.