Deteriorated condition detecting apparatus for an oxygen sensor
Steady state mode oxygen sensor and method
Oscillatory mode oxygen sensor and method
Sensor for oxygen-combustibles gas mixtures
Gas analysis apparatus
Air-to-fuel ratio sensor Patent #: 4568443
ApplicationNo. 361717 filed on 05/30/1989
US Classes:123/679, Combined with engine condition responsive means123/688, Inoperative sensor responsive123/691, Multiple sensors controlling group of cylinders204/401, Fault testing of sensor or component204/410, Solid electrolyte means204/412, Three or more electrodes204/425With impressed current means
ExaminersPrimary: Argenbright, Tony M.
Attorney, Agent or Firm
Foreign Patent References
International ClassesG01N 027/58
Foreign Application Priority Data1985-10-18 JP
AbstractA device for detecting and measuring the concentration of a gas in a mixture of gas such as oxygen in the exhaust gas of an internal combustion engine and circuits for using that measurement to control the air-fuel ratio supplied to the engine. The detecting device has two separate gas residence chamber with different diffusion resistance openings for each chamber and separate pairs of electrodes for each chamber whereby the measurement can be separately made in each chamber. The particular chamber selected for measurement may be done on the basis of whether the air-fuel ratio is lean or rich whereby a substantially linear reading results for all ratios or on the basis of the transition-state or steady-state operating condition of the engine to provide either more rapid or more accurate readings. Further, by using the cells from both chambers to compare their readings and standards, the actual readings can be corrected for abnormalties that may occur after a period of use or to indicate the detector has become defective.