The Passive Radon-Thoron Discriminative Dosimeter for Practical Use.

Electret ion chamber-based passive radon-thoron discriminative monitors.

Electret ion chambers (EICs), commercially available under brand name E-PERM(®), are widely used for measuring indoor and outdoor (222)Rn concentrations in air. These are designed to respond only to (222)Rn and not to (220)Rn by restricting diffusional entry area. Such radon EIC (R EIC) monitors are modified by increasing the entry area to allow (220)Rn, in addition to (222)Rn. Such modified un...

Thoron spike test for passive radon detectors.

Sensitivity to Thoron on Passive Radon Detectors

INTRODUCTION Although a lot of studies on radon have been done for a long time, there are few reports on thoron. It was considered that the presence of thoron could be negligible because of its own quantity compared to that of radon. However, recent studies have shown high thoron levels in our living environment (1-4). In particular, high thoron concentrations were occasionally observed in some...

Bronchial dosimeter for radon progeny.

A true bronchial dosimeter has been designed, consisting of four 400-mesh wire screens and a filter paper. With a face velocity of 3.3 cm s(-1) for home exposure and 4.6 cm s(-1) for mine exposure, the deposition pattern on the wire screens were found to satisfactorily match the variation of the dose conversion factor (in units of mSv WL M(-1)) with the size of radon progeny from 1 to 1000 nm. ...

The Concept of Equivalent Radon Concentration for Practical Consideration of Indoor Exposure to Thoron

To consider the total exposure to indoor radon and thoron, a concept of equivalent radon concentration for thoron is introduced, defined as the radon concentration that delivers the same annual effective dose as that resulting from the thoron concentration. The total indoor exposure to radon and thoron is then the sum of the radon concentration and the equivalent radon concentration for thoron....