In order to measure the concentrations of 222Rn and 220Rn in indoor air
the slightly refitted 10cm charcoal canister has been used for active sampling. After sampling
the charcoal canister has been measured by using a gamma- ray spectrometer and a HPGe detector. After calibration
concentrations of 222Rn and 220Rn have been obtained according to two characteristic Y peaks at 352 and 239keV. For 222Rn and 220Rn calibration factors were 0.263 and 0. 182m3Bq-1min.-1
respectively
The above validation method has been tested by measuring 222Rn and 220Rn concentrations in one general laboratory and one dwelling under different conditions. The 222Rn concentration has been found to be 45.5 - 140Bq. m-3 and the 220Rn concentration to be 4.92-14.2Bq . m-3