Thermoelectric thick-film hydrogen gas sensor operating at room temperature

A sensor of thick film NiO doped with alkali ions was fabricated and coated with Pt as the catalyst on half of its, surface. When this sensor was expo sed to air mixed with hydrogen gas, the catalytic reaction heated up the Pt -coated surface, and then thermoelectric voltage appeared across the hot an d cold region of the oxide film. At 22 degreesC, the sensor showed the buil t-up temperature difference and voltage signal of 0.12 degreesC and 0.087 m V, respectively, for the 100 ccm flow of 3% hydrogen/air mixed gas, with th e full response time, T-90, of 55 s.