| 摘要 |
PURPOSE:To detect radioactive gas with high accuracy even if its concn. is in low level by providing an eliminating apparatus of radioactive gas and calibrating the measured values by means of radiation detector with the measured value after said gas has eliminated. CONSTITUTION:On the front stage of a radioactive gas concentrating apparatus 20, a radioactive gas eliminating apparatus 12 and a by-path pipe 17, which go round said apparatus 12, are provided. And, the sample gas is made to pass through into said apparatus 12 with the channel control valves 10a, 10b changing over to eliminate said gas. The values measured through the radioactive detector are calibrated with the values after eliminating radioactive gas. |
