Active Shielding EMF Shielding Materials Low-Frequency Magnetic Fields Magnetic Shielding MRI Shielding Mu-Metal Shielding Passive Magnetic Shielding Magnetic Shielding Materials: Steel, Mu-Metal, and Active Coil Comparisons How steel, mu-metal, copper, and active compensation coils each control magnetic fields, and how to choose the right ... National Shielding Updated on Jun 15, 2026