{
  "id": "quantities:magnetic-flux-density",
  "collection": "quantities",
  "slug": "magnetic-flux-density",
  "name": "Magnetic flux density",
  "summary": "The quantity an ELF gaussmeter reports, expressed in milligauss or microtesla, used to assess wiring, transformers and power lines. 1 µT = 10 mG.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "B field",
      "magnetic field",
      "gauss",
      "tesla"
    ],
    "quantityId": "magnetic-flux-density",
    "symbol": "B",
    "siUnit": "T",
    "units": [
      {
        "symbol": "T",
        "name": "tesla",
        "toBase": 1
      },
      {
        "symbol": "mT",
        "name": "millitesla",
        "toBase": 0.001
      },
      {
        "symbol": "µT",
        "name": "microtesla",
        "toBase": 0.000001
      },
      {
        "symbol": "nT",
        "name": "nanotesla",
        "toBase": 1e-9
      },
      {
        "symbol": "G",
        "name": "gauss",
        "toBase": 0.0001
      },
      {
        "symbol": "mG",
        "name": "milligauss",
        "toBase": 1e-7
      }
    ],
    "measures": "Magnetic component of a low-frequency field. Passes through walls and almost all shielding materials, so mitigation is by distance or by fixing the current imbalance that creates it.",
    "conversions": [
      {
        "to": "magnetic-flux-density",
        "formula": "H (A/m) = B (µT) / 1.25663706",
        "note": "Magnetic field strength H relates to flux density B by the permeability of free space, µ₀ = 4π × 10⁻⁷ H/m. 1 A/m ≈ 1.2566 µT in air."
      }
    ],
    "related": [
      "limits:sbm-2024-magnetic-bands",
      "limits:icnirp-2010-public-magnetic-50-60"
    ]
  },
  "sources": [
    {
      "id": "nist-si",
      "title": "The International System of Units (SI), NIST Special Publication 330",
      "publisher": "National Institute of Standards and Technology",
      "url": "https://www.nist.gov/pml/special-publication-330",
      "kind": "government",
      "retrieved": "2026-08-12"
    },
    {
      "id": "sbm-2024",
      "title": "Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)",
      "publisher": "Institut für Baubiologie + Nachhaltigkeit (IBN)",
      "url": "https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf",
      "year": 2024,
      "kind": "ngo",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/quantities/magnetic-flux-density",
    "html": "https://emfbase.com/quantities/magnetic-flux-density",
    "markdown": "https://emfbase.com/quantities/magnetic-flux-density.md",
    "collection": "https://emfbase.com/api/quantities"
  }
}