CCTF Working Group on the Expression of Uncertainties in Primary Frequency Standards

摘要

The Comite Consultatif pour la Definition de la Seconde* (CCDS) created in March 1996 a Working Group on the expression of uncertainties in primary frequency standards. This paper presents the main topics included in the first report of the Working Group dated April 1997. This report gives a brief review of the conditions which led to the creation of the Working Group and a summary of the discussions which took place at its first meeting held in Neuchdtel, Switzerland, on 5 March 1997, and also during the following weeks. A main objective of the Working Group is a better understanding between laboratories which evaluate the accuracy of their primary frequency standards and their clients represented by the Bureau International des Poids et Mesures (B1PM) which uses the measurements provided by these standards for assessing the accuracy of TAI (Temps Atomique International, or International Atomic Time) and UTC. An important point for this purpose is the application to primary frequency standards of the guidelines expressed in the Guide to the Expression of Uncertainty in Measurement.