European Measurement Comparisons of Environmental Radioactivity

摘要

The scheme of European measurement comparisons to verify radioactivity monitoringin the European Union is briefly explained. After a review of comparisons conducted during theyears 1990, the approach of IRMM organising these comparisons since 2003 is presented.IRMM is providing comparison samples with a reference value traceable to the SI units andwhich is fully documented to all participants and national authorities after completion of thecomparison. The sample preparation and determination of traceable reference values at IRMM,the sample treatment and measurement in the participating laboratories, as well as the evaluationof comparison results are described in some detail using the example of an air filter comparison.The results of a comparison to determine metabolised ~(40)K, ~(90)Sr and 137)Csin milk powder arepresented as well. The necessary improvements in the estimation of measurement uncertainty bythe participating laboratories are discussed. The performance of individual laboratories whichhave participated in at least four comparison exercises over the years is studied in terms ofobservable trends.