The impedance change in an eddy current test coil is most easily analyzed as a combined change in:

In eddy current testing, the primary analysis revolves around how much the impedance of the coil changes in response to the presence of conductive materials and defects. Impedance in an electrical circuit encompasses both resistance and reactance. In the context of eddy current testing, changes in impedance can be represented through the signal amplitude and phase shift.

Signal amplitude relates to the strength of the response detected by the coil, which varies with changes in material properties or geometrical configurations. The phase shift provides critical information about the nature of the conductive material and its interaction with the eddy currents generated within the test coil. By analyzing both of these factors together, inspectors can draw conclusions regarding the condition of the tested component.

This choice emphasizes the practical application of signal processing in eddy current testing. It highlights how the measurement data is interpreted to identify defects or material properties, making it a crucial concept for effective analysis in this nondestructive testing method.