The NRPB radon personal dosimetry service

A radon personal dosemeter has been developed. The dosemeter is simple, cheap, robust, disposable and indelibly numbered. The operation principle is that of a radon diffusion chamber, which principle has been established both experimentally and theoretically. The dosemeter is an enclosure which excludes radon progeny and detritus whilst allowing access of radon gas. The alpha particles from the decay of radon gas, and from radon progeny, which are, in the main, plated out on the detector and on the dosemeter walls, are registered in a piece of poly allyl diglycol carbonate (PADC). The number of alpha particle tracks recorded is proportional to the time integral of the radon gas concentration external to the dosemeter. Since December 1986, NRPB has been offering a dosimetry service approved by the appropriate UK authorities.