How is depth of penetration defined in the context of Eddy Current Testing?

Depth of penetration in Eddy Current Testing refers specifically to the effective depth that eddy currents can flow into a material before their strength diminishes significantly. This concept is crucial because it determines the maximum depth at which these currents can detect faults or inhomogeneities within conductive materials.

Eddy currents are induced in conductive materials by an alternating electromagnetic field, and their intensity decreases as they penetrate deeper into the material. The depth of penetration is influenced by several factors, including the frequency of the alternating current, the conductivity, and the magnetic permeability of the material being tested.

Understanding this depth allows technicians to assess whether they can effectively detect defects or variations within a given thickness of material. The significance of this depth is paramount when choosing the right testing parameters for inspecting various components.