Development of magnetic flux leakage measuring system for detection of defect in small diameter steam generator tube

Magnetic flux leakage based non destructive technique for detection of defect in small diameter steam generator tube is evaluated. The detect-ability of a flaw depends on the magnetic flux density passing through a specimen to be inspected. The process of magnetizing local region of the small diameter tube is complex, when the magnetizer arrangement is placed inside the tube. Bobbin coil is considered to magnetize the local region of small diameter ferromagnetic tube and a hall sensor is placed at the center of the magnetizer to sense the leakage field. ANSYS Maxwell EM V16 based Finite Element Method (FEM) and Analytical model is used to validate the proposed magnetizer arrangement. Experimental results were found to be in good agreement with both numerical and analytical results. The obtained results suggest that the performance of the proposed bobbin coil is good to inspect the small diameter tube.