Shape Reconstruction Method for Imaging Conductive Materials in Electrical Capacitance Tomography

One of the innovative application of the tomography process is detecting the size and the location of the grounded metal in the Lost Foam Casting (LFC). Traditional methods based on fixed sensitivity matrix for solving the inverse problem are failed while the other dynamic methods for updating the sensitivity matrix are consuming time. A design of a narrow band level set method to reconstruct the interfaces between the grounded objects and the foam patterns is discussed. The level set method is a well suited method compared with the traditional pixel based image reconstruction methods for the case of the grounded metal. This method can provide more accurate solution for recovering the shape and the place of the grounded metal. Two difficult problems are associated with the ECT system for the grounded material, sensitivity matrix calculation and the shielding problem. The effect of the grounded metal on the sensitivity matrix is studied and the shielding problem is demonstrated. The final results, based on simulations, demonstrate the advantage of using the shape reconstruction method to track the shape and the location of the grounded metal in the imaging area.