Is there ever a time at which a small magnetic field can eventually saturate magnetic shielding of very high quality such as MuMetal? Or can magnetic shielding block the magnetic field indefinitely? Would layers help?
According to this manufacturer, mu-metal saturates at a field of 0.8 Tesla (or 8000 Gauss)
A magnetic shield redirects and concentrates the field within the shield - preventing the field from adversely effecting any components or wiring outside of the shield. The shield will do this indefinitely.
materials like mu-metal have very high magnetic permeability; but they will eventually saturate if you apply a sufficiently high external field. If the external field is low, the mu-metal doesn't saturate. The shielding action will last indefinitely, as long as the shielding doesn't degrade or break the use of multiple layers can increase the shielding factor, considerably
