Two-filter monitor for atmospheric 222Rn

Abstract
A two‐filter, continuous monitor has been developed for atmospheric 222Rn. Features include a sensitivity of better than 0.01 pCi/l, a high specificity for 222Rn, and immediate start up capability. The monitor has been computer modeled to facilitate calibration and selection of operating parameters. The filters are stationary and require no moving parts for control. Field trials indicate high reliability and maintenance‐free operation for periods of a week and longer.