Design of Eddy Current Probe with TMR Components for Detection of Inner Defects in Thin Metallic Structure

Non Destructive testing (NDT) methods have a wide field of application in manufacturing and maintenance industries. Inner defect detection in conductive plates represents an important issue in NDT. Base on theoretical analysis of eddy current technique, Probe with TMR (Tunneling Magneto Resistance), components is designed to detect this kind of inner defect. By selecting the position of maximum variation where TMR is fixed, the inner defects 2mm beneath metal surface can be detected. The simulation results indicated the design of No-differential where TMR is fixed on the top to excitation winding is the optimum design in term of the variation of amplitude magnetic field. The work is significant, which could provide theoretic guidance in manufacturing probe and experiment.