Air fuel ratio measuring system
US4799018A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 11, 1987 |
| Grant date | Jan 17, 1989 |
| Priority date | — |
| Expiry date | Aug 11, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4065
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A detecting element (6) comprising a solid zirconia electrolyte (6a), a reference electrode (6d), a detecting electrode (6c) and a diffusion member (6a) is provided, and also a driving circuit (1b, 4) for impressing a voltage between the electrodes (6c, 6d) of said detecting element so as to detect the threshold current of an oxygen ion pumping current (I.sub.p) is provided. The output of this driving circuit is delivered as a continuous output (V.sub.o) of an air fuel ratio of fuel gas comprising al the regions of rich, stoichiometric and lean air fuel ratios. On the other hand, an I.sub.p detection resistor (Rs) for detecting the pumping current flowing between the input/output terminals of the driving circuit is provided. The opposite-end voltages (V.sub.a, V.sub.o) of this I.sub.p detection resistor are compared by a comparator (5), and a step signal corresponding to the stiochiometric air fuel ratio (.lambda.) is outputted from this comparator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.