Roy C. Preston
Stephen P. Robinson
Div. of Radiation Sci. and Acoust., Natl. Phys. Lab., Teddington, Middlesex TW11 0LW, UK
EUROMET is a formal structure of contacts between National Metrology Institutes in Europe aimed at enhancing collaboration and coordinating research into new and improved measurement standards. A EUROMET project was established to undertake a survey of underwater acoustical calibration facilities with particular emphasis on primary standards and methods of dissemination. The results of the survey have been published in a report available from NPL [S. P. Robinson and R. C. Preston, RSA(EXT)32 (April 1992)]. This report lists the 64 organizations that provided information for the survey and describes facilities existing in each of the 17 participating countries. One of the findings of the study is that the concepts of primary and secondary standards and the associated methods of dissemination to users are not as well developed in underwater acoustics as they are in other fields of metrology, e.g., in the measurement of air-borne sound. Nevertheless, there is considerable activity in the field, and assuring the quality of measurements is now realized as being important in the move toward a single European market. A review of the concepts of measurement traceability as applied to underwater acoustics will be presented, together with an overview of the results of the EUROMET study with special emphasis on the UK facilities.