Research On Sensing Principle Of Vector Field Projection For Amorphous Wires

Amorphous wire is an amorphous alloy microfilament,with a small size,high sensitivity and other characteristics.When using high-frequency alternating current to drive an amorphous wire,the ac impedance at both ends of the amorphous wire changes significantly through the tiny external magnetic field of the amorphous wire.This effect is called the giant magneto-impedance effect widely used in a wide range of magnetic field sensor materials.In order to further enhance the spatial sensing resolution of amorphous wire in vector field,improve the measurement accuracy of amorphous wire,and increase the capability of developing giant magneto-impedance effect,this paper studies the theoretical analysis method of giant magneto-impedance in arbitrary magnetic field.Through the study of the unique magnetic domain structure and magnetization mechanism of amorphous wire,the mechanism of inducing giant magneto-impedance effect has been found out.Based on the magneto-impedance effect of amorphous wire,a vector field projection model of amorphous wire was established based on the principle of the sensing property of the amorphous wire,which was used for the tomography of vector field.Based on the magnetization model analysis of amorphous wire in vector field,the proper electromagnetic field equation and boundary definition are listed,and the expression of surface impedance tensor is given.The approximate equations in the case of two kinds of limit parameters at high frequency and low frequency are obtained by means of progressive series expansion.This allows us to quantitatively analyze the influence of applied magnetic field amplitude on the impedance tensor of an amorphous wire.A theoretical model of giant magneto-impedance effect is established by combining the change of magnetic domain structure of amorphous wire with the minimization of the free energy of the internal system of amorphous wire.The effects of different DC bias and anisotropy on the surface tension of amorphous wire The influence law of the amount of component shows the driving principle of the magneto-impedance effect of amorphous wire.Aiming at the sensing model of amorphous wire in vector field,two kinds of demagnetization factors of amorphous wire under different definitions are deduced.The influence of transverse magnetic field on the amorphous wire is analyzed.Finally,it is confirmed that in the case of DC bias,The linear working range of anisotropic hysteresis amorphous wire can be used for vector field tomography.