ラドン・トロン混在場におけるパッシブ法の共同比較測定 Intercomparison of Passive Devices in the Radon and Thoron Mixed-Field
An intercomparsion exercise on passive radon-and radon/thoron-devices was carried out under the participation of seventeen organizations in Japan during a one-year period from June 1992 to May 1993 in two Japanese traditional wooden houses, in which radon and thoron concentrations had been clearly measured beforehand. Methods used for the intercomparison were electrostatic collection using a solid-state nuclear-track detector (SSNTD), a thermoluminescent dosimeter (TLD) and a pin-photodiode detector (PPD) as detectors, cup methods with SSNTD using a filter cup, and a method using a bare SSNTD. Each participant selected a device or a method and a set exposure time; one, two, three, four, six, ten or twelve months. Radon and thoron concentration levels were about 20-50Bq/m<sup>3</sup> for radon and 10-40Bq/m<sup>3</sup> for thoron in the house in Nagoya, Aichi Prefecture, and about 5-30Bq/m<sup>3</sup> for radon and 20-200Bq/m<sup>3</sup> for thoron in the house in Seika, Kyoto Prefecture. The results of measurements for radon were as follows: in the case of the house in Nagoya, a great number of devices agreed at 20% deviation and all data entered in range twice; and in the case of the house in Seika, a larger deviation was found in the data. Measurements for thoron showed that there was clearly a discrepancy between concentrations obtained in each house, respectively, and that thoron concentration in the room decreased as distance from a wall increased.
- 保健物理 : hoken buturi
保健物理 : hoken buturi 32(3), 265-276, 1997-09-30
Japan Health Physics Society