| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air-fuel ratio sensor and an air-fuel ratio detector for detecting, by a simple structure, air-fuel ratios wide ranging from an oxidizing atmosphere to a reducing atmosphere. <P>SOLUTION: A pumping cell 2 comprises a solid electrolyte 21 for a pump and electrodes 22a and 22b for a pump. When passing a constant current through the electrodes 22a and 22b of the pumping cell 2, oxygen gas of a definite concentration is pumped out from the electrode 22a toward the electrode 22b and introduced into a gas rate-determining body 4. An exhaust gas also is introduced into the rate-determining body 4. The exhaust gas is mixed with the pumped-out oxygen gas of the definite concentration in the interior. Further, a cell 3 for oxygen concentration measurement comprises a solid electrolyte 31 for measurement and electrodes 32a and 32b for measurement. The cell 3 is supplied with a mixed gas of a gas under measurement and the pumped-out oxygen gas of the definite concentration. When placing a constant voltage between the electrodes 32a and 32b of the cell 3, a current corresponding to the concentration of oxygen in the mixed gas flows through the electrodes 32a and 32b. <P>COPYRIGHT: (C)2007,JPO&INPIT |
