The Role of the Fundamental Constants of Physics in Metrology

The paper discusses the recent measurements of the fundamental physical constants whose various combinations serve to provide the natural units of measurement in physics and the evaluation of their recommended values by the CODATA Task Group on Fundamental Constants. It emphasizes the strong involvement of the SI units with the present evaluations and shows how the fundamental physical constants play an increasing role in defining and maintaining many of the SI units of today and in sustaining the integrity of our measurement system. The present situation is reviewed and the evolving role of the fundamental physical constants in science and technology is discussed.