Exhaust gas sensor and system thereof
US6136170A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1997 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Dec 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/0047
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides an apparatus for measuring the concentration of a constituent to be detected in exhaust gas, which apparatus is capable of detecting with a high accuracy the concentration of the constituent to be detected in exhaust gas even though oxygen concentration in the exhaust gas varies. In an exhaust gas sensor 1 for use in the measuring apparatus, exhaust gas is introduced into spaces 15, 16 on both sides of an oxygen concentration cell element 4, and the oxidation catalyst activities of first to third electrodes 11 to 13 are adjusted so that there occurs a difference between the space 15 and the space 16 in consumption of the constituent to be detected, which consumption is caused by the oxidation of the constituent. Thus a concentration cell electromotive force is generated in the oxygen concentration cell element 4, and an oxygen pump element 3 pumps oxygen into or out of the space 15 so that the electromotive force is held at an target value EC not more than 10 mV. The pump current at this time is taken as the detection output on the constituent to be detected. The strengths of the oxygen concentration cell element 4 and of the oxygen pump element 3 can…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.