{
  "id": "protocols:shielding-verification",
  "collection": "protocols",
  "slug": "shielding-verification",
  "name": "Shielding verification",
  "summary": "How to prove a shielding measure worked: identical instrument, position and source conditions before and after, reported in dB as well as in absolute units.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "test shielding effectiveness"
    ],
    "goal": "Quantify the actual installed attenuation of a shielding measure, rather than relying on the datasheet figure.",
    "quantity": "attenuation",
    "equipment": [
      "broadband-rf-meter",
      "spectrum-analyser",
      "directional-antenna"
    ],
    "steps": [
      "Before installation, record fixed-position readings in both peak and average mode, with the dominant source direction noted.",
      "Where possible use a stable reference source rather than ambient network traffic, whose level changes minute to minute.",
      "Install the measure, then repeat the readings at the identical positions with identical meter settings.",
      "Express the result as a ratio and in dB: 10 · log₁₀(S_before / S_after).",
      "Check the perimeter, seams, window reveals and any penetration for leakage, which usually dominates the result.",
      "Confirm no new problem was created: re-measure the AC electric field if a conductive surface was installed."
    ],
    "pitfalls": [
      "Using ambient cellular traffic as the reference, so the before/after difference is mostly network load variation",
      "Expecting the datasheet dB figure; installed performance is routinely 10–20 dB worse",
      "Ignoring reflection: enclosing a transmitter can raise levels inside the enclosure",
      "Leaving a conductive surface ungrounded and increasing the low-frequency electric field"
    ],
    "interpretAgainst": [
      "quantities:shielding-attenuation"
    ],
    "related": [
      "shielding:paint",
      "shielding:window-film"
    ]
  },
  "sources": [
    {
      "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/protocols/shielding-verification",
    "html": "https://emfbase.com/protocols/shielding-verification",
    "markdown": "https://emfbase.com/protocols/shielding-verification.md",
    "collection": "https://emfbase.com/api/protocols"
  }
}