Sensor for detecting variation in oxygen concentration in gas
US4101403A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1976 |
| Grant date | Jul 18, 1978 |
| Priority date | — |
| Expiry date | Dec 13, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4071
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor comprising a plate of an oxygen ion conductive solid electrolyte such as stabilized zirconia, two porous electrode layers of a catalytic metal such as platinum formed on both sides of the electrolyte plate, and two porous ceramic coatings formed respectively on the two electrode layers, wherein both sides of the electrolyte plate are exposable to a gas subject to measurement through the electrode layer and the coating formed on each of them, but the total resistance offered by one of the electrode layers and the coating thereon to the permeation of the gas therethrough is different from that offered by the other electrode layer and coating, so that the gas contacts one side of the electrolyte plate with a time lag behind the contact of the gas with the other side of the plate. The sensor is useful for detecting a fluctuation in the air/fuel ratio of an air-fuel mixture fed to an internal combustion engine across the stoichiometric ratio by exposure to the exhaust gas since the fluctuation and the aforementioned time lag causes the sensor to develop an output voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.