Depth Profile Scanning of Cylindrical Bar and Wire Using a Spectroscopic Direct Current Injection Technique

S J Dickinson, R Binns, A J Peyton and W Yin

Engineering department, Lancaster University, Lancaster, Lancs LA1 4YR, UK Email: s.dickinson@lancs.ac.uk

ABSTRACT

The theoretical development of a spectroscopic direct current injection technique for determining coating properties and coating thickness on lengths of conductive material having a circular cross- section is considered. The use of multiple frequencies enables the depth of field penetration to be scanned and thereby layer properties to be deduced. The paper discusses the development of an analytically derived forward model, the inversion of this model and the verification of the forward model using an independent finite element model for comparison.

Keywords Multi-frequency, Electromagnetic, Depth profiling, Model inversion.