@prefix isq: .
@prefix smart: .
@prefix rdf: .
@prefix dcterms: .
@prefix skos: .
a isq:Entry ;
rdf:type isq:Quantity ;
rdf:type smart:TermEntry ;
dcterms:identifier "7-34" ;
skosxl:prefLabel "reflectance factor"@en ;
skosxl:altLabel "R"@en ;
skos:definition "quotient of the flux reflected in the directions delimited by a given cone with apex at a surface element and the flux reflected in the same directions by a perfect reflecting diffuser identically irradiated or illuminated, expressed by\n\n[stem%unnumbered]\n++++\nR=Phi_\"n\"/Phi_\"d\"\n++++\n\nwhere stem:[Phi_\"n\"] is the flux reflected in the directions delimited by a given cone and stem:[Phi_\"d\"] is the flux reflected in the same directions by an identically irradiated diffuser of reflectance (<>) equal to 1\n"@en ;
smart:hasBindingnessType "bindingness-type:normative" ;
dcterms:isPartOf ;
isq:hasUnit [
skos:notation "1" ;
skosxl:prefLabel "one"@en
] ;
skos:note "The flux can be a radiant flux (<>) or a luminous flux (<>).\n\nThe definition holds for a surface element, for the part of the reflected radiation contained in a given cone with apex at the surface element, and for incident radiation of given spectral composition, polarization and geometric distribution.\n\nReflectance factor is equivalent to radiance factor (<>) or luminance factor (<>) when the cone angle is infinitely small, and is equivalent to reflectance (<>) 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 (<>) or transmittance (<>) equal to 1 is called a perfect diffuser.\n"@en ;
iso:urn .