| 摘要 |
PURPOSE:To enable the accurate determination of the carbon dioxide gas concentration in a gas, by cooling the gas sucked from a thermostatic chamber to a specific temperature, and measuring the thermal conductivity of the gas. CONSTITUTION:In the case of controlling the concentration of carbon dioxide gas at a specific level within 0-20% in an atmosphere having a temperature of 5-50% and a humidity of >=95% such as a thermostatic chamber for the culture of cancer cell, and especially in the case of detecting the carbon dioxide gas concentration by the thermal conductivity of the gas, the gas sucked from the thermostatic chamber is cooled with a cooler 10 and is kept at a definite temperature higher than freezing point, e.g. at 10 deg.C. The relative humidity of the specimen gas reaches nearly 100%, and is maintained at about a constant level even if there is some fluctuation of the humidity in the thermostatic chamber. Accordingly, the influence of the humidity fluctuation on the thermal conductivity can be eliminated, and the concentration of the carbon dioxide gas can be determined accurately. |
