Related Experiment Video
Updated: Sep 22, 2025
Quantifying the Relative Thickness of Conductive Ferromagnetic Materials Using Detector Coil-Based Pulsed Eddy Current Sensors
Published on: January 16, 2020
Phase-Extraction-Based MFL Testing for Subsurface Defect in Ferromagnetic Steel Plate
Chengjian Ma1, Yang Liu1, Changyu Shen1
1China Jiliang University, Hangzhou 310018, China.
Abstract:
Magnetic flux leakage (MFL) based on phase extraction for detecting the subsurface defects in ferromagnetic steel plate was investigated. The relationship between electromagnetic field phase and the subsurface defect was analyzed. Low-frequency alternating current (AC) excitation source and high-power magnetizer arrangement with Hall sensor were used to increase the skin depth of the MFL. Experiments results showed that 12 mm deep subsurface defect can be detected by using the phase extraction means, which is about two times higher than that by using the amplitude method.
Related Concept Videos
01:18Magnetic Flux
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
01:31Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...