Directional magnetic Barkhausen noise measurement using the magnetic needle probe method

Abstract

A directional local magnetic measurement technique as example of measuring the angular dependence of the magnetic Barkhausen noise in electrical and construction steels at typical quasi-static frequency by the magnetic needle probe (MNP) method is presented. The directional measurement configuration of the MNP method is typical of a half-turn search coil sensor coupled to high gain analogue amplification and high order filtration stages, owing to its very weak induced electromotive force. The method exploits the MBNenergy(H) hysteresis cycle (time integration of the square of the MBN voltage signal as a function of the tangent excitation field H) and brings forth stable indicators possibly related to the Magnetocrystalline Anisotropy Energy (MAE). Experimental tests performed on grain-oriented Fe-Si and low carbon steel specimens, and comparison with the conventional search coil measurement results were worth the validation of the MNP method. These results put to the front the good directional selectivity of the MNP method over the conventional MBN sensors adversely affected by the transverse fields at the material surface. Eventually, the printed magnetic needle probe (PMNP) sensor was relatedly described to provide non-invasive directional measurements for continuous structural health monitoring.

Magnetic Signatures and Magnetization Mechanisms for Grinding Burns Detection and Evaluation

“… The point probe method [ 36 ]: experimental picture ( a ), 2D illustration and equation ( b ), graphical description of μ sat the magnetization rotation indicator ( c ). …”

Effect of stress on the magnetic Barkhausen noise energy cycles: A route for stress evaluation in ferromagnetic materials

“…Similarly, material anisotropy and its influence on MBN and stress evaluation are usually ignored. Material anisotropy, however, can be considered by controlling the magnetic excitation direction (rotating magnetic field [27][35] or inductor [44] [45]) or controlling MBN measurement direction (directional sensor [46]).…”

Internal Characterization of Magnetic Cores, Comparison to Finite Element Simulations: A Route for Dimensioning and Condition Monitoring

“…In [27], we specifically focused on embedding a B ⃗ sensor (where B ⃗ is the magnetic flux density (induction field) averaged through the tested specimen cross-section). We used the printed magnetic needle probes method (PMNPM) (also described in [28]), in which the conventional needle probe [29], [30] is replaced with a printed probe. The resulting sensor exhibits a thickness of a conductive ink layer (≈30 μm).…”