What is the main purpose of spring-loaded eddy current probe coils?

The main purpose of spring-loaded eddy current probe coils is to minimize lift-off variations. Lift-off refers to the distance between the probe coil and the surface of the test material. Any variations in this lift-off distance can lead to inconsistencies in the measurements obtained during nondestructive testing (NDT). By employing a spring-loaded mechanism, the probe can maintain consistent contact pressure with the surface, helping to ensure that the distance remains stable even if there are slight variations in the surface profile or during the testing process. This stability is crucial for obtaining accurate and reliable test results.

While other options may address issues relevant to probe usage, they do not focus on the primary function of spring-loaded designs in the context of minimizing lift-off impact on measurement accuracy. Reducing wear on the probe, alleviating operator fatigue, or eliminating edge effect are not the main goals of the spring-loaded mechanism, which primarily enhances measurement reliability.