PRINCIPLE THEORY OF MTM
Local stresses (either from physical defect or non physical) will cause changes in magnetic field strength.
Measurement of magnetic field strength to evaluate the local stresses degree of danger.
Assessment of Stress Deformed State base on Magnetoelastic effect (Villary effect)
Villary Effect - The Higher the mechanical stress, The Higher the magnetic field intensity.
PRIMARY OBJECTIVE OF NONCONTACT MTM
Evaluates defects based on the relative change in local stress levels in pipeline.
NOT evaluates defects based on physical features/dimensions of the pipeline defects (like other
conventional NDT techniques).