Inter-comparison of passive radon detectors
Radon is the largest and most variable source of public exposure to radiation. Surveys of radon levels have been carried out to determine the magnitude of average exposures and to identify situations where excessive exposures occur. In order to assess the quality of these measurements by comparing different detectors side by side, the European Commission has funded a series of inter-comparison meetings. A report documenting the results of the first inter-comparison meeting has recently been published. A total of 62 laboratories submitted 74 sets of measurements from 40 passive detectors. These detectors were exposed to radon and its decay products and then returned to their originating laboratories for assessment. Participants reported the estimated exposure for each detector before they were notified of the exposures given to the detectors. The inter-comparison included three laboratory exposures at different equilibrium factors. The results are presented in a series of tables which provide the following information: - Parameters measured and controlled in the NRPB radon chamber; - Laboratories participating in the inter-comparison; - Air treatment during laboratory exposures; - Exposure durations and magnitudes; - Radon results from passive detectors; - EER results from passive detectors; - Radon results ranked by category; - Minimum standard deviations achieved by different standard detector types.