id: https://nde.nl/ontology/hc/slot/max_annual_light_exposure
name: max_annual_light_exposure_slot
title: Maximum Annual Light Exposure Slot
description: 'Maximum acceptable cumulative annual light exposure in lux-hours.


  **ISO STANDARD REFERENCE VALUES**:

  - EN 16893:2018 (High sensitivity): <15,000 lux-hours/year

  - EN 16893:2018 (Medium sensitivity): <150,000 lux-hours/year

  - CIE 157:2004 (Textiles): <12,000 lux-hours/year

  - ASHRAE Guidelines: <50,000 lux-hours for sensitive materials


  **CUMULATIVE EXPOSURE EXAMPLES** (at 50 lux):

  - 8 hours/day, 250 days/year = 100,000 lux-hours

  - 4 hours/day, 250 days/year = 50,000 lux-hours


  **PRESERVATION CONTEXT**:

  Light damage follows the reciprocity law (Bunsen-Roscoe law): total exposure

  matters, not intensity alone. Annual limits ensure rotating displays and

  controlled access periods for highly sensitive materials.

  '
prefixes:
  linkml: https://w3id.org/linkml/
  hc: https://nde.nl/ontology/hc/
  qudt: http://qudt.org/schema/qudt/
  quantitykind: http://qudt.org/vocab/quantitykind/
  qudt_unit: http://qudt.org/vocab/unit/
  sosa: http://www.w3.org/ns/sosa/
  ssn: http://www.w3.org/ns/ssn/
  crm: http://www.cidoc-crm.org/cidoc-crm/
  wd: http://www.wikidata.org/entity/
  schema: http://schema.org/
  dcterms: http://purl.org/dc/terms/
  prov: http://www.w3.org/ns/prov#
  skos: http://www.w3.org/2004/02/skos/core#
  rdfs: http://www.w3.org/2000/01/rdf-schema#
  org: http://www.w3.org/ns/org#
  xsd: http://www.w3.org/2001/XMLSchema#
imports:
- linkml:types
default_prefix: hc
slots:
  max_annual_light_exposure:
    description: "Maximum acceptable cumulative annual light exposure in lux-hours per year.\n\nBased on preservation standards:\n- High sensitivity (EN 16893): <15,000 lux-hours/year\n- Medium sensitivity (EN 16893): <150,000 lux-hours/year\n- Textiles (CIE 157): <12,000 lux-hours/year\n- General guidance (ASHRAE): <50,000 lux-hours/year\n\nLight damage is cumulative (reciprocity law). Annual limits mandate:\n- Rotating displays for sensitive works\n- Controlled access periods\n- Dark storage between exhibition periods\n\nExample: 50 lux \xD7 8 hours/day \xD7 250 days = 100,000 lux-hours (too high!)\n"
    range: float
    slot_uri: hc:maxAnnualLightExposure
    close_mappings:
    - sosa:ObservableProperty
    - crm:E54_Dimension
    related_mappings:
    - quantitykind:LuminousExposure
    - wd:Q194411
    - schema:maxValue
    minimum_value: 0.0
    maximum_value: 500000.0
    see_also:
    - https://www.nen.nl/en-16893-2018-en-274167
    - https://cie.co.at/publications/control-damage-museum-objects-optical-radiation
    examples:
    - value: 12000.0
      description: Maximum for textiles (CIE 157)
    - value: 15000.0
      description: Maximum for highly sensitive materials (EN 16893)
    - value: 50000.0
      description: General guidance for sensitive materials (ASHRAE)
    - value: 150000.0
      description: Maximum for moderately sensitive materials (EN 16893)
    annotations:
      qudt_unit: unit:LUX-HR
      ucum_code: lx.h
      iso_reference: EN 16893:2018, CIE 157:2004
      preservation_parameter: 'true'
      calculation_note: "lux-hours = illuminance (lux) \xD7 exposure time (hours)"
      custodian_types: '["*"]'