Patent ID: 11899002
Assignee: NGK INSULATORS, LTD.
Field: Measurement (Instruments)
Classification: CPC G  Y | IPC G

Claim 14:
15. The method for controlling operation of said gas sensor according to claim 14, wherein
said sensor element further includes:
a gas inlet through which said measurement gas is introduced from an external space;
a first internal space communicating with said gas inlet under predetermined diffusion resistance;
a main pump cell as one of said at least one pump cell, said main pump cell including an inner pump electrode as one of said first electrode located to face said first internal space, an out-of-space pump electrode as said second electrode located to face a space other than said first internal space, and said solid electrolyte between said inner pump electrode and said out-of-space pump electrode as one of said part made of said solid electrolyte between said first electrode and said second electrode;
a second internal space communicating with said first internal space under predetermined diffusion resistance;
an auxiliary pump cell as another one of said at least one pump cell, said auxiliary pump cell including an auxiliary pump electrode as another one of said first electrode located to face said second internal space, said out-of-space pump electrode, and said solid electrolyte between said auxiliary pump electrode and said out-of-space pump electrode as another one of said part made of said solid electrolyte between said first electrode and said second electrode;
a measurement electrode as yet another one of said first electrode located inside said sensor element, at least one diffusion control part being located between said measurement electrode and said second internal space;
a measurement pump cell as yet another one of said at least one pump cell, said measurement pump cell including said measurement electrode, said out-of-space pump electrode, and said solid electrolyte located between said measurement electrode and said out-of-space pump electrode; and
a reference electrode located inside said sensor element and capable of being in contact with a reference gas,

said gas sensor further includes:
a first variable power supply to apply a main pump voltage between said out-of-space pump electrode and said inner pump electrode;
a second variable power supply to apply an auxiliary pump voltage between said out-of-space pump electrode and said auxiliary pump electrode; and
a third variable power supply to apply a measurement pump voltage between said out-of-space pump electrode and said measurement electrode,

in said steady state of operation,
said first variable power supply applies said main pump voltage so that an oxygen concentration in said first internal space is constant,
said second variable power supply applies said auxiliary pump voltage so that an oxygen concentration in said second internal space is constant, and
said third variable power supply applies said measurement pump voltage so that oxygen generated through decomposition of NOx in said measurement electrode is pumped out.