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Resolution 7 of the 21st CGPM (1999)
Version française
The definition of the kilogram

    The 21st Conférence Générale des Poids et Mesures,


  • the need to assure the long-term stability of the SI,
  • the intrinsic uncertainty in the long-term stability of the artefact defining the unit of mass, one of the base units of the SI,
  • the consequent uncertainty in the long-term stability of the other three base units of the SI that depend on the kilogram, namely, the ampere, the mole and the candela,
  • the progress already made in a number of different experiments designed to link the unit of mass to fundamental or atomic constants,
  • the desirability of having more than one method of making such a link,
  • recommends that national laboratories continue their efforts to refine experiments that link the unit of mass to fundamental or atomic constants with a view to a future redefinition of the kilogram.

Comptes Rendus de la 21e CGPM (1999), 2001, p.331
Metrologia, 2000, 37(1), 87-98

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

Other Resolutions of the 21st CGPM (1999)
Resolution 1
Resolution 2
Resolution 3
Resolution 4
Resolution 5
Resolution 6
Resolution 7
Resolution 8
Resolution 9
Resolution 10
Resolution 11
Resolution 12
Resolution 13