GB/T 3658-2022
软磁金属材料和粉末冶金材料20Hz~100kHz频率范围磁性能的环形试样测量方法
Methods of measurement of the magnetic properties of magnetically soft metallic and powder materials at frequencies in the range 20 Hz to 100 kHz by the use of ring specimens
GBT3658-2022, GB3658-2022