Design and Implementation of a Rotating Magnetic Field Probes for Barkhausen Noise Measurement

This study presents an optimal probe structure for rapid and reliable measuring of the “Directional Barkhausen noise” (DBN). The dependence of barkhausen noise on a rotating magnetic field is an efficient measure for the evaluation of residual stress, magnetic anisotropy and magnetocrystalline energy. Barkhausen noise has a nonlinear relationship with the intensity of the magnetic field, therefore, to ensure the accuracy of this test, it is necessary to be sure that the intensity of the field remains constant during rotation. In practice, it is not possible to measure magnetic flux inside the material, but it can be estimated by using simulation tools at any point of the sample or the excitation core. Three kinds of probe structures to generate a uniform rotating magnetic field are proposed and analyzed. These probes enable continuous measurements in any direction and provide a more comprehensive characterization of material properties. Subsequently, the related experimental setup was implemented based on the optimal design of the probe that produces a uniform rotating magnetic field.