What is one critical factor that affects the sensitivity of Eddy Current Testing?

The frequency of the eddy currents is a critical factor that significantly impacts the sensitivity of Eddy Current Testing. As the frequency increases, the depth of penetration of the eddy currents into the material decreases. This causes the eddy currents to become more concentrated near the surface, which enhances the ability to detect surface-breaking cracks or other near-surface defects. Conversely, lower frequencies allow the eddy currents to penetrate deeper, which may be advantageous for detecting subsurface defects but can reduce sensitivity to small, surface-level flaws.

A well-selected frequency can thus optimize the detection capability for specific applications, making it crucial to consider when designing an Eddy Current Testing procedure. By adjusting the frequency, technicians can tailor the inspection to be more responsive to the specific characteristics of the material being tested and the types of defects anticipated.