Equivalence in radionuclide metrology

The harmonization of different National Measurement Systems depends on the ability to demonstrate Equivalence between them. The responsibility for est ablishing a procedure to achieve this lies with the International Committee of Weights and Measures (CIPM) and its associated Consultative Committees. In pursuit of these ends, a series of general recommendations and procedur es have been developed by BIPM in order to achieve these objectives. Centra l to these recommendations is the concept of Key Comparisons which involve a series of comparison exercises both within and between the regional metro logy organizations, such as EUROMET, NORAMET and APMP. Because of the uniqu e nature of radioactivity standardization, this generalized procedure is. f or practical purposes, impossible to apply in the field of radionuclide met rology. The remedy has been the development of a protocol which optimizes b oth the current effort available within existing National Metrology Institu tes (NMIs) and the considerable amount of data from previous intercompariso ns. This paper details this novel approach, provides practical examples, di scusses potential problems and examines the way in which the programme will continue and expand. Crown Copyright (C) 2000 Published by Elsevier Scienc e Ltd. All rights reserved.