Performance review of a slide scanner based automated counting system for PADC radon detectors

The HPA operates a radon measuring service determining the radon concentration (Bqm-3) in enclosed areas using passive PADC (CR-39) detectors. Since 2003 over 116,000 radon detectors have been analysed in the laboratory using a Nikon LS2000 slide scanner. Digital images of the etched PADC are analysed by in-house etched-track and area counting software. The slide scanner method is briefly described along with its performance across the dynamic range of the detectors. Blind Tests, validation and other quality assurance performance results are reported and discussed.