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Part 77-11.3
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Part 7: Light and Radiation·66 entries
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Section 7-114 entries
7-11.17-11.27-11.37-11.4
7-11.3

maximum luminous efficacy

URNurn:iso:std:iso:80000:-7:ed-2:en:item:7-11.3
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urn:iso:std:iso:80000:-7:ed-2:en:item:7-11.3
ISQ Identifiers
ISO
urn:iso:std:iso:80000:-7:ed-2:en:item:7-11.3
IEC
urn:iec:std:iec:80000-7:2019:::item:7-11.3
Designations
ENmaximum luminous efficacy
FRefficacité lumineuse maximale
Symbol
K m
Notation systems
Rendered
K m
AsciiMath
K_"m"
LaTeX
K_{\text{m}}

Definition

EN

maximum value of spectral luminous efficacy for a specified photometric condition

FR

valeur maximale de l'efficacité lumineuse spectrale pour une condition photométrique spécifiée

Units

l m W
lumen per watt
View related quantities →
c d ⋅ s r ⋅ k g − 1 ⋅ m − 2 ⋅ s 3
candela steradian second cubed per kilogram square metre
View related quantities →

Notes

EN

See also cls-0.4 and cls-0.5.

The value of maximum luminous efficacy for photopic vision is calculated by

K m = 683 V ( λ cd ) unitsml(cd*sr*W^(-1)) ≈ 683 unitsml(lm*W^(-1))

where V ( λ ) is the spectral luminous efficiency for photopic vision and λ cd is the wavelength in air corresponding to the frequency 540 ⋅ 10 12 unitsml(Hz) specified in the definition of the SI unit candela.

Symbols for different photometric conditions:

K m , ; K ′ m , ; K m,mes;m , ; K m , 10 , ; K m,M , .

FR

Voir également cls-0.4 et cls-0.5.

La valeur de l'efficacité lumineuse maximale en vision photopique est calculée par

K m = 683 V ( λ cd ) unitsml(cd*sr*W^(-1)) ≈ 683 unitsml(lm*W^(-1))

où V ( λ ) est l'efficacité lumineuse relative spectrale en vision photopique et λ cd est la longueur d'onde dans l'air correspondant à la fréquence 540 ⋅ 10 12 unitsml(Hz) spécifiée dans la définition de l'unité SI de la candela.

Symboles pour différentes conditions photométriques:

K m , ; K ′ m , ; K m,mes;m , ; K m , 10 , ; K m,M , .

Referenced by

luminous efficiency <specified photometric condition>spectral luminous efficacy <specified photometric condition>luminous energyluminous fluxluminous intensityluminanceilluminanceluminous exitanceluminous exposuretristimulus values for the CIE 1931 standard colorimetric observertristimulus values for the CIE 1964 standard colorimetric observer
Concept HierarchyPendrill (2024)
L⁻² M⁻¹ T³ JL⁻² M⁻¹ T³ J quantitiesLevel 0 · Kind

Ontology
isq:Quantitysmart:TermEntry

Class Hierarchy

smart:Entitysmart:TermEntryisq:Quantity

A physical quantity as defined in ISO/IEC 80000, with associated symbols, definitions, and units of measurement.

Instance IRI

isq:t7-11.3

Properties

isq:QuantityShape
PropertyValue
rdf:type
isq:Quantitysmart:TermEntry
dcterms:identifier
7-11.3
skosxl:prefLabel
"maximum luminous efficacy <specified photometric condition>"@en
skosxl:altLabel
"K_"m""@en
skos:definition
maximum value of spectral luminous efficacy for a specified photometric condition
skos:note
See also <<cls-0.4>> and <<cls-0.5>>. The value of maximum luminous efficacy for photopic vision is calculated by [ste…
isq:hasUnit
lm/W (lumen per watt)cd*sr*kg^(-1)*m^(-2)*s^3 (candela steradian second cubed per kilogram square metre)
isq:hasDimension
isq:Dimension
smart:hasBindingnessType
bindingness-type:normative
dcterms:isPartOf
isq:part-7

Related Entities

isq:QuantityShape isq:part-7 isq:Unit isq:Dimension isq:hasDimension smart:TermEntry