{
  "$type": "site.standard.document",
  "description": "Exhaust gas purification process comprises determining the concentration of the NOx compounds in the form of a NOx model value downstream of the NOx storage catalyst; measuring the concentration of the NOx compounds in the form of a NOx measured value downstream of the catalyst in the exhaust gas…",
  "path": "/patents/1097075",
  "publishedAt": "2003-04-02T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B01D53/9431",
    "SIEMENS AG [DE]"
  ],
  "textContent": "Exhaust gas purification process comprises determining the concentration of the NOx compounds in the form of a NOx model value downstream of the NOx storage catalyst; measuring the concentration of the NOx compounds in the form of a NOx measured value downstream of the catalyst in the exhaust gas pipe; and determining the difference between the NOx measured value and the NOx model value and using to correct the condition parameter in the model. Preferred Features: The NOx measured value or the NOx model value is low-pass filtered before forming the difference. The degree of charge of the catalyst is used as the condition parameter. The difference is coupled with a conversion factor to produce a correction parameter for the condition parameter.",
  "title": "Exhaust gas purifying method for lean burn engines"
}