Catalyst deterioration diagnosis method, method for purification of exhaust gas using the diagnosis method, catalyst deterioration diagnosis apparatus, and apparatus for purification of exhaust gas using the diagnosis apparatus
US8984861B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2013 |
| Grant date | Mar 24, 2015 |
| Priority date | — |
| Expiry date | May 25, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A catalyst deterioration diagnosis method for diagnosing deterioration of a catalyst for purification of exhaust gas by using a test catalyst disposed in an exhaust gas flow path through which the exhaust gas flows, the method including an exhaust gas control step of inverting an air-fuel ratio of the exhaust gas in the flow path from a lean side to a rich side or from a rich side to a lean side; a measurement step of measuring a change over time in electrical resistance of the test catalyst at the inversion of the air-fuel ratio and finding a resistance change ratio of the test catalyst; and a determination step of determining catalytic deterioration of the test catalyst based on the resistance change ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.