candela, cd

https://doi.org/10.1351/goldbook.C00787
The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540×1012 Hz, Kcd, to be 683 when expressed in the unit lm W−1, which is equal to cd sr W−1, or cdsrkg−1m−2s3, where the kilogram, metre and second are defined in terms of h, c and ΔνCs.
Source:
BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 135 [Terms] [Book]
Citation: 'candela' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C00787 RIS BibTex EndNote
Div. IBIPMPDFTextXMLJSONUnit