– the intergovernmental organization through which Member States act together
     on matters related to measurement science and measurement standards.
Search facility:

| Site map | News | Contact us
CIPM, 1946: Resolution
Version française
Definition of photometric units*


  1. The photometric units may be defined as follows:

New candle (unit of luminous intensity) - The value of the new candle is such that the brightness of the full radiator at the temperature of solidification of platinum is 60 new candles per square centimetre.

New lumen (unit of luminous flux) - The new lumen is the luminous flux emitted in unit solid angle (steradian) by a uniform point source having a luminous intensity of 1 new candle.

  1. ...

Procès-Verbaux des Séances du CIPM (1946), p. 119


The two definitions contained in this Resolution were ratified in 1948 by the 9th CGPM, which also approved the name candela given to the "new candle". For the lumen, the qualifier "new" was later abandoned. This definition was modified in 1967 by the 13th CGPM (Resolution 5).
Consultative Committees
CIPM publications
Joint Working Groups
ad hoc Working Group on Governance
Strategic planning: BIPM and Consultative Committees
CIPM Sub-Committees and ad hoc Groups
CIPM election process
Members of the CIPM
Photographs of the CIPM
CIPM Decisions and Recommendations