特殊用法A.C. demagnetization1.交流去磁additional demagnetization1.附加去磁adiabatic demagnetization1.绝热退磁(作用)pulse demagnetization1.脉冲退磁recording demagnetization1.录音前的去磁demagnetization by continuous reversals1.周期改变磁通方向的去磁