Multi-parameter estimation by combining dimensional analysis and eddy current testing

This paper presents a novel methodology for the simultaneous estimation of geometrical and physical parameters of a Non Destructive Testing system based on Eddy Currents. Specifically, the simultaneous estimation of the thickness and electrical conductivity of metallic samples and the lift-off interposed between the eddy current probe and the metallic sample under test is addressed. The proposed methodology uses dimensional analysis to address the problem, making use of Buckingham's π theorem to develop a simple and effective estimation procedure. In this paper, we demonstrate the validity of the proposed methodology in a simulated environment, while also considering experimentally characterized measurement noise, in different case studies in terms of thickness, electrical conductivity, and lift-off.