Bias in the measurement of radon gas using ionization chambers: Application to SIR
Abstract
Two main non-destructive techniques can be used to measure standard Rn-222 gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Systeme International de Reference (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass. Results showed that variability of the gas ampoules induced measurement bias larger than the uncertainty of the standard sources.