| 摘要 |
PURPOSE:To detect the density of concentrated gas highly accurately by making gas containing a specific component and concentrated gas increasing the density of the specific component flow into a heat conductivity type gas sensor at a fixed flow rate ratio and using the gas containing the specific component as reference gas. CONSTITUTION:For instance, air containing oxygen is used as the gas containing the specific component and oxygen-concentrated gas is used as the concentrated gas increasing the density of the specific component. The concentrated gas is led into a sample gas cell 4 at a flow rate V2 through a filament 1 and then the gas is made to flow from an ejector 8 into a room 5. Air to be used as the reference gas is led into a reference gas cell 3 at a flow rate V1 through a filament 2 and then made to flow into the room 5 through the ejector 8. In this case, the ejector 8 sets up the flow rates V1, V2 to a fixed flow rate ratio. The resistance changes of the filaments 2, 1 due to the oxygen density in the concentrated gas and the air are detected by a galvanometer 6 to detect the oxygen density of the concentrated gas. Since the material gas mixture of the concentrated gas is used as the reference gas, the density of the concentrated gas can be detected highly accurately independently of the kind of gas. |
