Method of determining deterioration of oxygen concentration sensor
US4938194A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1989 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Jun 27, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1456
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of determining the deterioration of an oxygen concentration sensor for an internal combustion engine. The oxygen concentration sensor includes at least one oxygen concentration sensor element having an oxygen-pumping element and a cell element each composed of a member of a solid electrolytic material having oxygen ion-conductivity, and a pair of electrodes having the member interposed therebetween, and a current-detecting resistance serially connected to the oxygen-pumping element to form a series circuit. A voltage having a magnitude corresponding to a difference between a voltage produced between the electrodes of the cell element and a predetermined reference voltage is applied to the series circuit, and pumping current is detected from a voltage developed across the current-detecting resistance. The predetermined reference voltage is changed from a first predetermined value to a second predetermined value, followed by detecting a difference between a value of said pumping current detected when the predetermined reference voltage assumes the first predetermined value and a value of the pumping current detected when the predetermined reference voltage assumes the second…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.