Patent ID: 6733644
Filing Date: 2004-05-11
Classification: G01N

Abstract:
A gas sensor comprising:a sensor element formed of a solid electrolyte having an oxygen ion conductivity; a plurality of cathodes and an anode, each formed of a porous metal material and each formed on the sensor element, to produce a pumping current reflecting a concentration of a detection component in a measurement gas when a predetermined voltage is applied between the cathodes and the anode, the detection component comprising oxygen, the measurement gas contacting the cathodes; and a plurality of means for controlling a gas diffusion of the measurement gas in such a manner that the oxygen pumping current varies in accordance with a pressure of the measurement gas, the measurement gas moving from a measurement atmosphere toward the cathodes by way of the means for controlling the gas diffusion, to thereby obtain information on the pressure of the measurement gas based on the oxygen pumping current, wherein the cathodes are provided as different pressure dependency electrodes, each of the different pressure dependency electrodes corresponding to one of the respective means for controlling the as diffusion in which the means for controlling the as diffusion are so adjusted in terms of gas diffusion resistance as to make a difference between the corresponding different pressure dependency electrodes in terms of pressure dependency of the oxygen pumping current to be outputted; and in which the information on the pressure of the measurement gas is generated based on the oxygen pumping current outputted from each of the different pressure dependency electrodes.