@prefix isq: <https://w3id.org/standards/isq/ontologies/core/> .
@prefix smart: <https://example.org/smart-sdu/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<isq:t7-33.1>
  a isq:Entry ;
  rdf:type isq:Quantity ;
  rdf:type smart:TermEntry ;
  dcterms:identifier "7-33.1" ;
  skosxl:prefLabel "radiance factor"@en ;
  skosxl:altLabel "beta_\"e\""@en ;
  skosxl:altLabel "(beta)"@en ;
  skos:definition "quotient of the radiance of a surface element in a specified direction and the radiance of the perfect reflecting diffuser or perfect transmitting diffuser identically irradiated and viewed, expressed by\n\n[stem%unnumbered]\n++++\nbeta_\"e\" = (L_\"e,n\")/(L_\"e,d\")\n++++\n\nwhere stem:[L_\"e,n\"] is the radiance (<<t7-6.1>>) of a surface element in a given direction and stem:[L_\"e,d\"] is the radiance of the perfect reflecting or transmitting diffuser identically irradiated and viewed\n"@en ;
  smart:hasBindingnessType "bindingness-type:normative" ;
  dcterms:isPartOf <isq:part-7> ;
  isq:hasUnit [
    skos:notation "1" ;
    skosxl:prefLabel "one"@en
  ] ;
  skos:note "The definition holds for a surface element of a non-self-radiating medium, in a given direction and under specified conditions of irradiation.\n\nRadiance factor is equivalent to reflectance factor (<<t7-34>>) or luminance factor (<<t7-33.2>>) when the cone angle is infinitely small, and is equivalent to reflectance (<<t7-31.3>>) when the cone angle is stem:[2pi \"unitsml(sr)\"]. These quantities are also defined spectrally and called spectral radiance factor stem:[beta(lambda)] and spectral reflectance factor stem:[R(lambda)].\n\nThe ideal isotropic (Lambertian) diffuser with reflectance (<<t7-31.3>>) or transmittance (<<t7-31.5>>) equal to 1 is called \"perfect diffuser\".\n"@en ;
  iso:urn <urn:iso:std:iso:80000:-7:ed-2:en:item:7-33.1> .