A low-cost Hall effect based Magnetic Flux Leakage Approach for Structural Monitoring: a feasability study

Magnetic flux leakage is a widely used non-destructive testing technique for detecting cracks/discontinuities in ferromagnetic components. Conventional systems are typically bulky and expensive, limiting their use to periodic inspections. This work presents the design and validation of a compact, low-cost magnetic flux leakage system based on a permanent NdFeB magnet and a 3-axis Hall-effect magnetometer, interfaced with an ESP32 microcontroller. As a benchmark sample for testing the device capabilities a fatigue cracked AISI304 samples have been used. The system is detecting and characterizing the crack position, length and tilt angle. Results show reliable crack detection up to 5.5 mm of distance sensor-to-sample. The preliminary study validates the system's ability to estimate the length and angle of inclination of cracks. The proposed setup demonstrates that low-cost, miniaturized magnetic flux leakage systems can support condition monitoring and embedded non-destructive testing applications.