Results of comparative measurements of photon radiation carried out in Munich, Dortmund and Bilthoven by the Physikalisch-Technische Bundesanstalt

As part of a project of the Commission of the European Communities the Gesellschaft fuer Strahlen- and Umweltforschung mbH (GSF), Munich, and the Staatliches Materialpruefungsamt Nordrhein-Westfalen (MPA), Dortmund irradiated personal dosemeters with Co-60 photon radiation. The task of the Physikalisch-Technische Bundesanstalt (PTB) in the project was to determine whether, for this quality of radiation, systematic differences existed between the exposures measured by the PTB and those measured by the institutes named above. The next stage involved comparative measurements conducted at the Rijksinstituut voor de Volksgezondheid (RIV) at Bilthoven in the Netherlands. All the measurements carried out in Munich, Dortmund and Bilthoven were completed in the period 12 to 18 July 1982. The comparative measurements showed that in the determination of exposure at the GSF in Munich and the MPA in Dortmund the measurement uncertainty was so slight as to be negligible for the irradiation of personal dosemeters. The primary standards measuring equipment at the RIV and the PTB showed no significant differences for the radiation qualities ISO 83 keV and Cobalt 60