@prefix isq: .
@prefix smart: .
@prefix rdf: .
@prefix dcterms: .
@prefix skos: .
a isq:Entry ;
rdf:type isq:Quantity ;
rdf:type smart:TermEntry ;
dcterms:identifier "7-16" ;
skosxl:prefLabel "illuminance"@en ;
skosxl:altLabel "E_\"v\""@en ;
skosxl:altLabel "(E)"@en ;
skos:definition "density of incident luminous flux with respect to area at a point on a real or imaginary surface, expressed by\n\n[stem%unnumbered]\n++++\nE_\"v\" = (\"d\"Phi_\"v\")/(\"d\"A)\n++++\n\nwhere stem:[Phi_\"v\"] is luminous flux (<>) and stem:[A] is the area (<>) on which the luminous flux is incident\n"@en ;
smart:hasBindingnessType "bindingness-type:normative" ;
dcterms:isPartOf ;
isq:hasUnit [
skos:notation "lx" ;
skosxl:prefLabel "lux"@en
] ;
isq:hasUnit [
skos:notation "cd*sr*m^(-2)" ;
skosxl:prefLabel "candela steradian per square metre"@en
] ;
skos:note "Illuminance can be derived from the spectral irradiance distribution by\n\n[stem%unnumbered]\n++++\nE_\"v\" = K_\"m\" int_0^(oo) E_(\"e\",lambda)(lambda)V(lambda)\"d\"lambda\n++++\n\nwhere stem:[K_\"m\"] is maximum luminous efficacy (<>), stem:[E_(\"e\",lambda)(lambda)] is the spectral irradiance (<>) at wavelength stem:[lambda] (<>), and stem:[V(lambda)] is spectral luminous efficiency (<>).\n\nIntegral limits can be confined depending on the spectral sensitivity of the detectors used as a sensor.\n\nThe corresponding radiometric quantity is \"irradiance\" (<>). The corresponding quantity for photons is \"photon irradiance\" (<>).\n\nThe quantity \"spherical illuminance\" is defined by the mean value of illuminance on the outer curved surface of a very small (real or imaginary) sphere at a point in space.\n\nIt can be expressed by\n\n[stem%unnumbered]\n++++\nE_(\"v\",0) = int_(4pi)L_\"v\"\"d\"Omega\n++++\n\nwhere stem:[Omega] is solid angle (<>) and stem:[L_\"v\"] is luminance (<>).\n\nIt can be expressed by the quotient of the luminous flux (<>) of all the light incident on the outer surface of an infinitely small sphere centred at the given point, and the area (<>) of the diametrical cross-section of that sphere.\n"@en ;
iso:urn .