| 摘要 |
PURPOSE:To enable detection of an air-fuel ratio over a wide range with good accuracy by providing a part for introducing atm. air and a part for introducing a gas to be measured with a partition wall of a solid electrolyte having an oxygen ion conductivity in-between and providing electrodes to contact respectively with the parts for introducing the atm. air and the gas on both surface of the solid electrolyte. CONSTITUTION:A plate 12 for introducing atm. air formed with a channel-shaped part 13 for introducing atm. air is laminated on a substrate 10 provided with a heater 11 for heating. A plate-shaped solid electrolyte 14 having oxygen ion conductivity is laminated thereon. A reference electrode 15 is provided by printing on the bottom surface of the electrode 14 and a pump electrode 16 and sensor electrode 17 are provided on the top surface corresponding to said electrode. A plate-shaped body 18 formed with a part 19 for introducing a gas to be measured into a window shape is laminated on the electrolyte 14 and a plate-shaped body 20 provided with a small hole 21 as a means for controlling the diffusion of the gas is laminated thereon. Pump current is supplied between both surfaces of the electrolyte 14 so as to maintain a specified ratio of oxygen partial pressure and the current value thereof is detected by which the air-fuel ratio of an internal combustion engine is detected unequivocally over a wide range from a rich to lean region with good accuracy. |
