| 摘要 |
<p>PURPOSE:To measure concentration of an object nuclide with high detecting performance by a relatively simple measurement when it is already known that a particle size of the nuclide to be the object is different from that of nuclide of natural radioactivity. CONSTITUTION:The air A containing particular radioactive substance is sucked, and the sucked air A is separated to first air A1 containing rough particle substance having a predetermined particle size or more and second air A2 containing fine particle substance having less than the predetermined particle size. The substance contained in the air A1 is collected on a first filter sheet 13c, and the substance contained in the air A2 is collected on a second filter sheet 23c. A radioactive ray emitted from the substance collected on the sheet 13c is detected by a first radioactive ray detector 14, a radioactive ray emitted from the substance collected on the sheet 13c is detected by a second radioactive ray detector 24, detected data of the detector 24 is measured mainly as natural radioactivity data, and detected data of the detector 14 is measured as radioactive data consisting of natural radioactivity and radioactivity except the natural radioactivity.</p> |
