| 摘要 |
The invention relates to a sensor which may be used to measure the humidity of air or of other gas mixtures, this sensor consisting of an alumina support on one face of which are printed two metal (preferably, but not necessarily, platinum) or carbon electrodes, covered with a layer of ceramic as a thick-film whose impedance decreases as the partial pressure of water vapour (pH2O) increases and which is prepared, according to the invention, by firing, at a temperature of 600-850 DEG C, an aqueous-alcoholic mixture consisting of an alkali metal fluoride [e.g. LiF (50-200 mg)], an alkaline-earth metal fluoride [e.g. BaF2 (50-300 mg)], a rare-earth metal oxide [e.g. Nb2O5 (100-200 mg)], an uranium salt [e.g. UO2CO3 (50-200 mg)] and silicon oxide [SiO2 (10-100 mg)], while the other face has a heating element which prevents the formation of condensation, and one or more thermistors for measuring the temperature of the sensor and/or of the gas phase. |
