Master Eddy Current Testing 2026: Kickstart Your Level I Journey!

In eddy current testing, establishing a lift-off baseline is about separating the effects of the probe’s distance from the surface from the signals caused by real material defects. Lift-off—the gap between the coil and the surface—changes the impedance reading even when the material is defect-free. By creating a baseline response at a known lift-off over a defect-free area, you get a reference for how the instrument should read without flaws. When you later inspect a region, you compare its reading to that baseline. Deviations that can’t be explained by lift-off indicate a potential defect, while changes that follow lift-off behavior are due to probe distance rather than a flaw. This makes defect detection more reliable and reduces false indications. It isn’t used to measure humidity, set calibration frequency, or determine coating thickness.