高导磁材料(如坡莫合金)在很低的磁场下就可以达到饱和,而在实验室内存在杂散磁场的情况下(包括地磁场),往往比材料的H_c(矫顽力〕还高,这些外加的杂散磁场对软磁材料测量结果影响很大。软磁材料做成的试样,在实验之前总受到不同程度的磁化,如地磁场的影响等……。因而使材料处于一个相应的剩磁状态,由于冲击法测量的是磁通的差值, Highly permeable materials, such as permalloy, saturate at very low magnetic fields, whereas in the presence of stray magnetic fields (including geomagnetic fields) in the laboratory, they tend to outweigh the Hc (coercivity) of the material High, these additional stray magnetic field on the soft magnetic material measurement results greatly affected soft magnetic material made of the sample, before the experiment has always been subject to varying degrees of magnetization, such as the influence of the earth’s magnetic field ... ... so that the material in A corresponding state of remanence, as measured by the impact of magnetic flux difference,