Study on the Method of Detection of the Marks of Ferromagnetic Material Based on the Array of Hall Element

This study introduces a new imaging method of detection mark s of ferromagnetic material, based on the Hall sensor array. Unlike the tr aditional NDT imaging technology, the technique presented is measuring magnetic field of ferromag netic material surface and reading the difference by imaging the magnetic signals to find the marks. The study also introduces the principle and the system architecture of t he method. Different from the method based on a single integrated linear hall sensor, this ne w method uses the surface array of Hall sensors. Sensor array method can improve the detection efficiency and spatial resolution but facing a key problem which is to reconstruction of the data scanning at different time and position. This study presents the processing method and res ults, the magnetic images of marks.