Wide-range air/fuel ratio sensor and detector using the same
US4844788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1988 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Oct 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/122
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An air/fuel ratio sensor has a porous alumina substrate, a limiting current type oxygen detecting section on the porous alumina substrate for detecting the air/fuel ratio in the fuel lean region, a resistance-variable type oxygen detecting section on the porous alumina substrate for detecting the excess air ratio .lambda. when .lambda. is equal to one, a gas decomposition type hydrogen detecting section on the porous alumina substrate for detecting the air/fuel ratio in the fuel rich region and a heater for heating the respective detecting sections to the optimum temperature in operation, whereby the sensor can detect the air/fuel ratio over all the fuel rich and lean regions. In addition the apparatus includes a comparing/discriminating section for comparing the output of the resistance-variable type oxygen detection section with a reference value to discriminate whether the ambient atmosphere is in either of the fuel rich or lean region, a switching control section for changing each of the limiting current type oxygen detecting section from its operative position to its inoperative position or vice versa, depending on the result from the comparing/discriminating section, and an o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.