外场对开磁路样品矫顽力测量的影响

The Influence of External Field on Measuring the Coercivity of a Magnetic Sample in Open Magnetic Circuit

本文用磁通门探头作零磁通指示器,系统研究了外场对于开磁路电工纯铁和永磁材料样品矫顽力测量的影响。找到沿样品两个方向磁化后,得到的矫顽力算术平均值不变原理。讨论了国际电工委员会标准IEC404—7,认为:①该标准第6.3条“对于螺线管退磁场两个方向的每一个都应测量电流”条件,不是唯一的。而永磁材料的矫顽力只需要在一个退磁场方向测量;②附录A1第b条,对“周围的磁场应该加以补偿或者对装置进行屏蔽,以减小外磁场低于0.5A/m”条件,不是必要条件。

This paper involved the influence of external field on measuringthe coercivity of the electrical iron and permanent materials sample in an openmagnetic circuit by using a fluxgate probe as the zero magnetic flux indi-cater.The author has found that arithmetic mean value of the coercivity mea-sured along two directions of sample axis is invariable.Discussing the standardof IEC 404—7,which was publicated in 1982,the author considered:1.It isn′t unique condition which is listed on item 6.3 of the standard,(i.e.“the current shall be measured for each of the two directions of the da-magnetizing field of the solenoid”).In fact,the coercivity of permanent mag-net need to be measured only along one direction of the damagnetizing field.2.It isn′t necessary condition which is listed on the “b” item of appendixAI,(i.e.“the ambient magnetic field should be compensated for or the equip-ment shielded to reduce the value of the field to below 0.5A/m”).