| 摘要 |
A system, an apparatus and a method are provided for measuring the concentration of a sample gas in an oxygen-containing carrier gas, and for analyzing the chemical constitution of an oxygen-containing gas. The system includes two g as detectors, and a flame ionization detector. Each gas detector includes a central, solid electrolyte inner detector tube, the central, solid electrolyte inner detect or tube comprising an oxide of a tetravalent metal which has been doped with an oxid e of an element having a valence less than four. A first inlet tube into, and a firs t outlet tube from, the central, solid, electrolyte inner detector tube permits the oxygen - containing gas to flow through the detector tube while substantially eliminating back- diffusion of air into the detector tube. An internal electrode is in contact with the interior of the detector tube, and has a first, electrically-conductive output lead. An external electrode is in contact with the exterior of the detector tube, and has a second, electrical ly- conductive output lead. First and second interfaces between the electrode and the detector tube are maintained at a predetermined temperature. Means provide the first interface with continuously-flowing, oxygen-containing carrier gas which also contains the sample gas whose concentration isto be measured. An outer, concentric non-porous tube i s spaced apart from the central, solid electrolyte inner detector tube, to provide an annulus therebetween. A second inlet tube into the annulus and a second outlet tube from the annulus allow the reference gas to flow through the annulus while substantially eliminating back-diffusion of air into the annulus. A second external solid electrolyte is maintained at the predetermined temperature as first interface. Means bathe the second interface with the reference gas. Means seal the various tubes to provide a sealed unit. Means are for measuring an electrical signal between said electrodes, the electrical signal being directly proportional to the concentration of said sample gas to be determined, thereby to determine the concentration of the sample gas directly as a linea r correlation of said electrical signal. These means provide a direct measurement of the amount of CO2, H2O and C, and the measurements are converted to equations which are solved electrically to give the carbon, hydrogen and oxygen contents of the gas.</S DOAB>
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