US EPA

3703443 

Journal Article 

Determination of the calibration factor for CR-39 based indoor radon detector 

Matiullah 

2013 

Yes 

Journal of Radioanalytical and Nuclear Chemistry
ISSN: 0236-5731
EISSN: 1588-2780 

298 

1 

369-373 

10.1007/s10967-013-2451-9 

WOS:000324546100046 

CR-39 based radon detectors are widely used in measuring indoor radon. In this regard, different groups have developed their own systems. However, before using any system for indoor radon measurements, it has, first, to be calibrated with a known source of radon. In the current study, CR-39 based NRPB type radon detector has been calibrated and presented. In this regard, about 200 holders for CR-39 were obtained from the Radiation Protection Division of the Health Protection Agency (former NRPB), UK and several thousand more similar detector holders, hereafter called NRPB type holders, were fabricated locally in Pakistan. Uranium ore samples of known grade were placed into the plastic containers of volume 5.4 x 10(3) cm(3) and CR-39 detectors were placed in the NRPB type holders and were then installed into the containers at a distance of 25 cm from the surface of the known grade ore samples. The containers were hermetically sealed and the detectors were allowed to expose to radon for 3 weeks. After 16 h etching in 25 % NaOH at 80 A degrees C, the measured track densities were related to the radon concentration. The calibration factor of 2.563 tracks cm(-2) h(-1)/kBq m(-3) was obtained. 

Calibration factor; NRPB type holder; Indoor radon; CR-39; Secular equilibrium; Back diffusion constant; Effective exposure time