Search facility:  
BIPM Home | Site map | Metrology portal | KCDB | JCTLM-DB | Contact us  
   
Resolution 6 of the 11th meeting of the CGPM (1960)
Version française
Other Resolutions
of the 11th CGPM

Summary
Participation at the General Conference
24th meeting of the CGPM (2011): Presentations by CC Presidents
See also: Reports from CC Presidents at previous meetings of the CGPM
Resolutions of the CGPM
Proceedings of the CGPM
Chain of responsibility
Procedure for a State to become a Member of the BIPM
Procedure for a State or Economy to become an Associate of the General Conference
Evolving Needs for Metrology in Trade, Industry and Society, and the Role of the BIPM
Direct access
 
Definition of the metre* (5) (7)

The 11th Conférence Générale des Poids et Mesures (CGPM),

considering

  • that the international Prototype does not define the metre with an accuracy adequate for the present needs of metrology,
  • that it is moreover desirable to adopt a natural and indestructible standard,
  • decides

    1. The metre is the length equal to 1 650 763,73 wavelengths in vacuum of the radiation corresponding to the transition between the levels 2p10 and 5d5 of the krypton 86 atom.
    2. The definition of the metre in force since 1889, based on the international Prototype of platinum-iridium, is abrogated.
    3. The international Prototype of the metre sanctioned by the 1st CGPM in 1889 shall be kept at the BIPM under the conditions specified in 1889.


    Reference:
    Comptes Rendus de la 11e CGPM (1960), 1961, 85

    Note:

    This definition was abrogated in 1983 by the 17th CGPM (Resolution 1).

    The reader should note that the official version of this Resolution is the French text.