| 摘要 |
<PICT:0424053/III/1> A constituent of a gas mixture is estimated by dividing a sample of the gas into two portions, removing the constituent from one of them, and passing the two portions simultaneously through a pair of thermal conductivity cells connected in a Wheatstone bridge in the known manner. The Figure shows an apparatus for determining carbon dioxide in engine exhaust gas. After passing through a drier 25 and filter 26 the sample is divided. One portion is passed through potassium hydroxide solution 32 and a drying tube 34 while the other portion is correspondingly delayed by passage through a coil 37. The two portions arrive simultaneously at the conductivity apparatus 22 and the difference in conductivity is indicated on the galvanometer scale 42. Flow gauges 35, 38 in the gas exit tubes enable the rates of flow to be equalized by means of the valve 36. |
