INTERNATIONAL COMPARISON OF ACTIVITY MEASUREMENTS OF XE-133

An international comparison of Xe-133 activity measurements has been c arried out under the auspices of EUROMET (project Nr 304). The project was divided into two stages concerning first the measurement of seale d glass ampoules containing about 40 MBq of Xe-133 at BIPM, LPRI, NPL and PTB and second the measurement at LPRI, NIST and NPL of the radioa ctivity concentration of Xe-133 mixed with nitrogen with an activity c oncentration of the order of 50 MBq mol(-1). The experimental techniqu es employed at each of the participating laboratories are described an d a statement of the results and conclusions is provided. (C) 1998 Els evier Science Ltd. All rights reserved.