A radon 222 traceability chain from primary standard to field detectors

The development of a primary standard from a method for measuring the absol ute activity of Rn-222 has also made it possible to establish secondary sta ndards. Detailed procedures to obtain these secondary standards are given. These standards are, in particular, adapted to the requirements of laborato ries that have developed equipment for the calibration and comparison of in struments measuring the concentration of radon and its daughters. An exampl e of the implementation of these new resources applied to the qualification of field detectors is given. The propagation of measurement uncertainties at each level (primary, secondary, lest radon chamber) is described. (C) 20 00 Elsevier Science Ltd, All rights reserved.