Nox gas sensor method and device
US7217355B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2005 |
| Grant date | May 15, 2007 |
| Priority date | — |
| Expiry date | May 25, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A50/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is a method and apparatus for measuring the total NOx concentration in a gas stream utilizing the principles of a NOx sensor, i.e., mixed potential sensor. The exhaust gas is first conditioned by a catalyst assembly that converts the various species of nitrogen oxide gases present to a fixed steady state concentration ratio of NO2/NO, where NO2 is approximately 0–10% of the total NOx concentration present in the gas exhaust, thereby enabling the NOx sensor to generate a meaningful and reproducible determination of the concentration of total NOx present in the gas being measured. The catalyst assembly also functions to oxidize any unburned combustibles such as CH4, CO, etc., and remove potential contaminants such as SO2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.