Gas sensor based on semiconductor oxide, for gaseous hydrocarbon determination
AssigneesEniricerche S.p.A., Snam S.p.A.
InventorsLucio De Angelis, Roberto Riva, Luciano Occhio
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Abstract
A sensor device for gaseous hydrocarbons includes two semiconductor oxide-based sensitive elements, one of which is a sensitive reference element and the other a sensitive measuring element, this measuring element being covered with a layer of electrically insulating porous material containing a dispersed noble metal. The two sensitive elements are formed by silk-screen processes, are connected to an electronic signal comparison system, and are maintained at different temperatures when in operation. The sensor has improved selectivity in determining gaseous hydrocarbons, in particular methane, even if high concentrations of interfering gases such as ethanol are present.
Claims9
A semiconductor oxide-based sensor device for methane and other gaseous hydrocarbons, comprising an insulating material support carrying a heating element on one of its major surfaces, and a sensitive measuring element and a sensitive reference element on its other major surface, characterised in that:
- said sensitive measuring element and said sensitive reference element are formed of crystalline tin oxide, alumina and noble metal and are in the form of thick film deposited by a silk-screen process;
- said sensitive measuring element is covered with a layer of electrically insulating porous material in which a noble metal is dispersed;
- said sensitive measuring and reference elements being heated by said heating element to mutually different temperatures and being operationally connected to an electronic comparator circuit able to measure the conductance which the sensitive elements assume by interaction with the gas, compare the signals emitted by the sensitive reference element and by the sensitive measuring element, and evaluate the presence and concentration of the hydrocarbon gas on the basis of said comparison of said signals.
Dependencies are inferred from the claim text.