Status of Radon Traceability and Calibration Techniques for Radon Gas

抄録

There are many calibration facilities of radon gas in the world, which are used to keep a measurement quality of radon mainly for purpose of radiation protection. Although there is only a limited number of techniques of a primary standard, each calibration facility employs several different techniques to establish a secondary calibration. The article summarized a status of radon traceability and the techniques used in the radon calibration facilities as well as the characteristics of each technique. In terms of geographical characteristics of calibration facilities, there was a biased distribution of a primary standard; only the US and Korea have a primary standard except in Europe. For differences in the technique used, it was found that operation modes may have an influence on the maximum radon concentration in the chamber and the time to reach a stable concentration. Types of radon sources may also affect the radon concentration in the chamber due to the difference in the emanation power of radon gas. The findings are expected to be utilized for the design and development of new radon calibration chambers in the future.