β-RAY GAS MONITOR AND METHOD FOR MONITORING GAS CONTAINING NUCLIDES EMITTING β-RAYS

摘要

A β-ray gas monitor 10 is provided with: a hollow main body 11, one open end of which is sealed airtight; a β-ray detector 12 arranged inside of the main body 11 so as to detect β-rays and output a detection signal s; a variable partition 13 which is provided so as to be capable of moving along the inner surface of the main body 11 while facing the detection port of the β-ray detector 12, and which is disposed at a partition position in accordance with the sample gas being measured so as to form, together with the inner surface of the main body 11, a sample space 14 that is separated from external space; a counting rate meter 17 for measuring counting rates on the basis of the detection signal s detected from the sample gas introduced into the sample space 14; and a radiation concentration calculation unit 36 for determining the concentration of radiation in the sample gas on the basis of the measured counting rate and the volume of the sample space 14.