Apparartus for detecting deterioration of catalysts
US5528898A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1995 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Sep 6, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A catalyst deterioration determination is performed in two stages. In the first stage of determination, an amplitude of an output signal from a downstream oxygen sensor is detected and this amplitude is compared with a reference value in order to determine possible deterioration in a catalyst. When correct performance is expected, while taking into account variations (amplitude and response) in the upstream and downstream oxygen sensors, then the detection in a second stage is omitted. However when possible catalyst deterioration may be present, the determination at the seconds stage is performed. After adjusting the response of the upstream oxygen sensor to the characteristic of the slowest response, the total response delay time of the downstream sensor is obtained within a specified amount of time, and this sum then is compared with a reference value indicating catalyst deterioration. A final determination is made as to whether catalyst deterioration is present.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.