An increase in the impedance of an eddy current test coil will result in what effect on current flow?

In an eddy current testing scenario, impedance is a crucial factor that impacts the behavior of the electrical current in the coil. When the impedance of a test coil increases, it means that the coil presents a higher opposition to the flow of alternating current (AC). This opposition is primarily due to both the resistive and reactive components of the impedance.

As impedance rises, the overall current flow through the coil decreases according to Ohm's Law, which establishes that current (I) is equal to voltage (V) divided by impedance (Z): I = V/Z. Therefore, if the impedance increases while the voltage remains constant, the current must decrease to maintain the relationship defined by Ohm's law.

This understanding of basic electrical principles clarifies why an increase in impedance leads to a reduction in current flow through the test coil in eddy current testing applications.