Non destructive testing - identification of defects in materials

In electrical impedance tomography (EIT) currents are applied through the electrodes attached on the surface of the object, and the resulting voltages are measured using the same or additional electrodes. Internal conductivity distribution is recalculated from the measured voltages and currents. The problem is very ill posed, and therefore, regularization has to be used. The aim is to reconstruct, as accurately as possible, the conductivity distribution s in phantom using finite element method (FEM). In this paper are proposed variations of the regularization term, which are applied to non-destructive identification of defects (voids or cracks) in conductive material.