| 摘要 |
PROBLEM TO BE SOLVED: To measure a minute quantity of gas emitted from a construction material and the like with high precision by measuring the gas while controlling a pressure inside the measurement atmosphere and a gas replacement ratio via both flow rate controlling means introducing and discharging gas into and from a measurement atmosphere. SOLUTION: Master controllers 7c, 100c respectively receive control signals Sx, Sy from a pressure controller 200 so as to control flow rates of gas flowing through an introduction passage 3 and an exhaust passage 100. When a gas measurement device 1 is operated, clean air introduced into a bubbling tank via the introducing passage 3 passes through ultra-pure water in the form of bubbles so as to be moved into a chamber 2 in the form of saturated air at a dew point. Air inside the chamber 2 is always replaced with new air at a fixed air replacement ratio under a predetermined fixed pressure, and a sample W such as a construction material is housed in the measurement atmosphere inside the chamber 2 so as to be applied to measurement for gas such as formaldehyde emitted from the sample W. In this way, minute gas emission can be stably detected under a clear pressure condition.
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