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High-permeability alloy (mu-metal) magnetic shielding

The only material class that meaningfully attenuates power-frequency magnetic fields, and even then typically by a factor of two to five in a retrofit — which is why distance and source correction are preferred.

panelingelf magnetic

Last verified 12 August 2026.

Also searched as: mu metal, magnetic shielding, nickel iron alloy

Form
paneling
Targets
elf magnetic
Grounding required
No
Datasheet attenuation
3–14 dB50/60 Hz magnetic; roughly a factor of 1.5–5 in field strength for practical retrofitssources: niehs-emf

Failure modes

  • Performance collapses if the sheet is bent, drilled or mechanically shocked after annealing
  • Saturates in strong fields, at which point it stops shielding
  • Only useful for compact, well-defined sources; useless against a whole-house net-current fault
  • Cost per square metre is orders of magnitude above RF materials for a much smaller benefit

Related records

  • High-voltage transmission line

    Fields directly beneath a loaded transmission line reach tens of milligauss and fall off roughly with distance for a balanced three-phase circuit, reaching background at 30–60 m for typical loadings.

    Sources & emitters

  • Magnetic flux density

    The quantity an ELF gaussmeter reports, expressed in milligauss or microtesla, used to assess wiring, transformers and power lines. 1 µT = 10 mG.

    Quantities & units

Sources

  1. niehs-emf Electric and Magnetic Fields National Institute of Environmental Health Sciences. government, link checked 2026-08-12.
  2. sbm-2024 Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024) Institut für Baubiologie + Nachhaltigkeit (IBN), 2024. ngo, link checked 2026-08-12.

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