Simulation and Design of a Balanced-Field Electromagnetic Technique Sensor for Crack Detection in Long-Distance Oil and Gas Pipelines

Due to the extremely small size and arbitrary orientation of cracks, a highly sensitive sensor based on balanced-field electromagnetic technique was designed for in-line inspection oil gas pipeline cracks. A mutual inductance model established used theoretically analyze parameters affecting sensitivity. Finite element simulation specific effects magnetically conductive medium, number coil turns, lift-off height output, respectively, high sensitivity were determined. The detection effect crack tested by single-sensor experiment pulling test. results show that is effective in detecting both circumferential axial cracks 0.5 6 mm depth. As depth increases, decreases voltage amplitude increases linearly. highest when 1 at 1.76 0.87 mV/mm, respectively. In addition, signal same approximately twice signal.