Radon exhalation rates from building materials using electret ion chamber radon monitors in accumulators.
An electret ion chamber (EIC) radon monitor in a sealed accumulator measures the integrated average radon concentration at the end of the accumulation duration. Theoretical equations have been derived to relate such radon concentrations (Bq m(-3) ) to the radon emanation rate (Bq d(-1)) from building materials enclosed in the accumulator. As an illustration, a 4-L sealable glass jar has been used as an accumulator to calculate the radon emanation rate from different granite samples. The radon emanation rate was converted into radon flux (Bq mm(-2) d(-1)) by dividing the emanation rate by surface area of the sample. Fluxes measured on typical, commercially available granites ranged from 20-30 Bq m(-2) d(-1). These results are similar to the results reported in the literature. The lower limit of detection for a 2-d measurement works out to be 7 Bq m(-2) d(-1). Equations derived can also be used for other sealable accumulators and other integrating detectors, such as alpha track detectors.
Kotrappa
Payasada
P
Rad Elec Inc., 5716-A Industry Lane, Frederick, MD 21704, USA. PKotrappa@aol.com
Stieff
Frederick
F
D000396:Air Pollutants, Radioactive / Q000032:analysis*; D003252:Construction Materials; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000379:methods; D011886:Radon / Q000032:analysis*
D000396:Air Pollutants, Radioactive; D011886:Radon