For the static method to measure magnetic hysteresis loops, more attention was paid to the mechanical operation and apparent description of the curves, while the underlying physical mechanism was ignored. It is necessary to survey the microscopic mechanism of the measurement of the magnetic properties of ferromagnetic materials in more details. By analyzing the principle of the experimental apparatus, examining the air-gap, shape, and nonuniformity of test materials, it is believed that the presence of air-gap influences the precision of the measurement, and the demagnetization induced by the nonuniformity of the material can weaken magnetization. According to repeated experimental experience, a method that can realize fast demagnetization was developed. Increasing the reverse magnetizing current can accelerate demagnetization, because demagnetization has no accumulative effect. The reverse demagnetizing current ranges from 160 to 180 mA. The process of magnetization, the magnetization curve and magnetic hysteresis loops are closely related to the magnetic domain structure. The process can be divided into two basic stages: the displacement of domain wall and rotation of the magnetization vector. By referring to the experimental results, the process of magnetization and reverse magnetization was theoretically discussed.%通过分析FD-BH-I实验仪器的工作原理,考察了待测材料的非闭合性、形状和不均匀度等仪器的细节因素,得出空气隙的存在会影响磁场的测量精度,不均匀和形状不规则的材料产生的退磁场会减弱磁化.根据反复退磁的实验经验,总结出了可以快速退磁的方法,因为退磁没有叠加效应,可以通过增大反向磁化电流实现快速退磁,反向退磁电流大都分布在160～180 mA.磁化过程以及它所决定的磁化曲线和磁滞回线与磁畴结构密切相关,可以分为畴壁位移和磁化矢量的转动两个基本的运动阶段.结合实验测量的结果,对磁化与反磁化过程的物理机理做了理论探讨.
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