Method for easily measuring nitrogen oxide concentration of an engine vehicle emission
US6886396B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 2002 |
| Grant date | May 3, 2005 |
| Priority date | — |
| Expiry date | Nov 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M15/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a method for easily measuring nitrogen oxide concentration of an engine vehicle emission. The method can measure vehicle emission from an engine of a vehicle in travel with high precision even in regions other than the lean region, that is, regions from the stoichiometrical region to the rich region by using a NOx sensor exclusively used for the lean region. The present invention has an arrangement in which a NOx sensor that is exclusively used for the lean region is installed in an exhaust pipe 3 connected to the engine 2. Air (secondary air) A is introduced into the exhaust pipe 3 on the upstream side of the NOx sensor 6 so that the NOx sensor 6 is allowed to measure the concentration of NOx in the engine vehicle emission diluted by air A. Thus, the NOx concentration in the engine vehicle emission before dilution G is obtained by using the measured value of the NOx concentration after dilution and by using a dilution ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.