IEVref:112-02-10ID:
Language:enStatus: Proposed
Term: candela
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Symbol: cd
Definition: SI unit of luminous intensity, taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540נ1012Hz, Kcd, to be 683 when expressed in the unit lmW−1

Note 1 to entry: The definition in the SI Brochure is:"The candela, symbol cd, is the SI unit of luminous intensity. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540נ1012Hz, Kcd, to be 683 when expressed in the unit lmW−1, which is equal to cdsrW−1, or cdsrkg−1m−2s3, where the kilogram, metre and second are defined in terms of h, c and ΔνCs."

Note 2 to entry: This definition applies to photopic vision, mesopic vision and scotopic vision.

Note 3 to entry: The candela is one of the seven SI base units: second (s), metre (m), kilogram (kg), ampere (A), kelvin (K), mole (mol) and candela (cd).


Publication date:
SourceSI Brochure, 9th edition, 2019, 2.3.1, modified – The definition in the SI Brochure has been revised to comply with the IEV rules. Notes 1 to 3 to entry have been added.
Replaces:112-02-10:2020-12
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