{
  "id": "glossary:shielding-effectiveness",
  "collection": "glossary",
  "slug": "shielding-effectiveness",
  "name": "Shielding effectiveness (dB)",
  "summary": "Attenuation expressed logarithmically: 10 dB removes 90% of power density, 20 dB removes 99%, 30 dB removes 99.9%.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "definition": "Shielding effectiveness is the ratio of incident to transmitted field, in decibels, at a stated frequency. Datasheet figures are measured on flat samples in a test fixture; installed performance is governed by seams, edges and penetrations and is routinely 10–20 dB worse. Because the scale is logarithmic, a small dB shortfall is a large change in transmitted power.",
    "category": "measurement",
    "seeAlso": [
      "quantities:shielding-attenuation",
      "protocols:shielding-verification"
    ]
  },
  "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/glossary/shielding-effectiveness",
    "html": "https://emfbase.com/glossary/shielding-effectiveness",
    "markdown": "https://emfbase.com/glossary/shielding-effectiveness.md",
    "collection": "https://emfbase.com/api/glossary"
  }
}