Assessment of the uncertainties in the Radiological Protection Institute of Ireland (RPII) radon measurements service

摘要

The RPII radon (Rn) laboratory holds accreditation for the International Standard ISO/IEC 17025. A requirement of this standard is an estimate of the uncertainty of measurement. This work shows two approaches to estimate the uncertainty. The bottom-up approach involved identifying the components that were found to contribute to the uncertainty. Estimates were made for each of these components, which were combined to give a combined uncertainty of 13.5% at a Rn concentration of approximately 2500 Bq m~(-3) at the 68% confidence level. By applying a coverage factor of k= 2, the expanded uncertainty is ±27% at the 95% confidence level. The top-down approach used information previously gathered from intercomparison exercises to estimate the uncertainty. This investigation found an expanded uncertainty of ±22% at approximately 95% confidence level. This is good agreement for such independent estimates.