A programmable gas sampler to measure the average radon concentration in a test chamber or in the field.

Abstract

A Tedlar gas sampling bag was used to retain samples of the test environment of interest. Samples, typically hourly, were transferred into a gas sampling bag. The volume of each sample was determined by a programmable timer or any computer capable of executing a compiled basic program. The program automatically adjusted the sample volume of each increment to exactly compensate for radioactive decay of radon referred to the end of the exposure period. At that time the radon activity collected in the sampling bag was the exact average for the whole period. A single Lucas cell was used to report the average concentration for typically 2 and 3 day exposures. The results compared with calculated predictions and with the average of a series of grab samples taken during the measurement period. The benefit of this method was the large work load reduction needed to determine the average concentration from a series of grab samples and the ability to employ Lucas cells, which are inherently more stable and less expensive than active measurement equipment normally used for chamber standardizations.