Patent · US Expired

Method for determining the reducing agent concentration (NH3) in the exhaust-gas flow of an internal combustion engine

US6571601B2 · kind B2 · utility

1Cited by

4References

3Claims

0Family size

Assignee

Conti Temic microelectronic GmbH · DE

Inventors

Eckard Irion · Waldenbuch, DE
Aleksandar Knezevic · Eitorf, DE
Holger Leye · Unterensingen, DE
Mirko Smuk · Philippsburg, DE

Key dates

Filing date	Aug 29, 2002
Grant date	Jun 3, 2003
Priority date	—
Expiry date	Aug 29, 2022

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02A50/20
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A method for determining the reducing agent concentration (NH3) in the exhaust-gas flow of an internal combustion engine, using a zeolitic NH3 gas sensor that supplies a base measuring value, which is initially corrected by an offset value and a correction value that depends on the H2O concentration of the exhaust gas to form an intermediate value. The intermediate value is subsequently corrected by an additional value that depends on the NOx and NH3 concentration of the exhaust gas. In particular at or above the limits for the operating range, the accuracy of the method increases for one of the following conditions: gas compositions with NOx concentrations >500 ppm, extremely low NH3 concentrations <20 ppm or high NH3 concentrations >100 ppm.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.