Why is the angle of the probe crucial during Eddy Current Testing?

The angle of the probe is crucial during Eddy Current Testing because it significantly affects the orientation of the induced eddy currents in the material being examined. When a probe is placed at an angle, the magnetic field generated by the probe's coil interacts differently with the conductive material. This interaction can influence how the eddy currents are generated and, consequently, the way they respond to defects or flaws within the material.

By positioning the probe at the correct angle, the inspector can maximize the sensitivity of the inspection to specific types of defects and material characteristics. For example, if the probe is aligned perpendicular to a crack or flaw, it may lead to more pronounced changes in the reflected signal, making it easier to detect the defect. This understanding is critical for interpreting the results correctly, as the distribution and impedance of the eddy currents are directly affected by the angle of the probe relative to the surface of the material.

In contrast, other aspects such as test frequency, measurement accuracy, or equipment selection, while important, do not directly involve the fundamental interaction between the probe and the induced eddy currents in the tested material.