Abstract
According to the lift-off effect of eddy current testing, a ferromagnetic absorbing coating thickness gauge was proposed in this paper. After comparison, hyperbolic regression model was adopted to estimate the relationship between the detecting coil impedance and the absorbing coating thickness. An efficient probe with high quality factor and temperature compensation was developed. At the same time, a novel and more flexible calibration method was designed in this paper to improve the measurement accuracy. The experimental results show that the thickness measurement error is less than 0.02 mm, which proves the validity of this absorbing coating thickness gauge.