Plating Thickness Evaluation based on Eddy Current Testing for CGL

Abstract

This paper explains a new technique based on the eddy current testing to evaluate plating thickness in the continuous galvanizing line. Previous techniques cannot apply to the line due to need low and/or fix liftoff. Because test samples are vibrated in the line by gas wipers. The new technique which we propose can evaluate the thickness with high and variable liftoff. Thus, the sensors based on the technique can install to near gas wipers which control the thickness and vibrate the samples in the line. First, the detection principle of the technique and the method of applying are explained on simulations by using the finite element method. Application results on measurement experiments are secondly explained. These results demonstrate the possibility of making thickness measurements using an eddy current with high and variable liftoff.