Ngk Insulators, Inc.

Yuichiro Kondo

Taku Okamoto

Nobuhiko Mori

Osamu Nakasone

Daichi Ichikawa

A sensor element includes first to third chambers communicating sequentially from a gas inlet, voltages are intermittently applied across inner electrodes facing the respective chambers and a reference pump electrode to perform pumping of oxygen between a measurement gas and the reference pump electrode being in contact with a reference gas, thereby to reduce HO and COin the measurement gas into Hand CO in the first chamber, to oxidize Hinto HO in the second chamber, to oxidize CO into COin the third chamber, and to identify a concentration of HO and a concentration of CObased on a pumping-in current at the time when electromotive force between an inner electrode and the reference pump electrode during non-application of a voltage is maintained at a target value.

Gas sensor and concentration measurement method using gas sensor

A gas sensor includes a sensor element including an element body, a first electrode, a second electrode, and a heater; a voltage acquisition section that acquires a voltage between the first electrode and the second electrode; a heater power supply; an external common lead that serves as both at least part of an electric circuit used to acquire the voltage by providing electrical continuity between the first electrode and the voltage acquisition section and at least part of an electric circuit used to supply an electric power from the heater power supply to the heater and that is disposed outside the sensor element; and a correction section that derives a value of a voltage drop in the external common lead in accordance with a heater current and that corrects the voltage acquired by the voltage acquisition section in accordance with the derived value of the voltage drop.

Gas sensor

A first gas sensor having a first sensor element includes a first protective cover that protects the first sensor element, and a second gas sensor having a second sensor element includes a second protective cover that protects the second sensor element. The first protective cover is coated with an oxidation catalyst for one target component from among a plurality of target components, and the second protective cover is coated with an inert catalyst for the one target component.

Gas sensor set and method of measuring concentrations of a plurality of target components within a gas to be measured

In a gas sensor, which measures a measurement pump current Ipof a measurement chamber, while switching a preliminary pump cell of a preliminary chamber ON or OFF at a constant period, there are formed in communication with each other sequentially from a gas introduction port in the interior of a structural body made from a solid electrolyte, a preliminary chamber, an oxygen concentration adjustment chamber, and a measurement chamber. The gas sensor rapidly determines a steady-state value of a measurement pump current Ip, based on a peak value of a rate of change over time dIp/dt of the measurement pump current Ip, thereby hastening an ON/OFF switching period of the preliminary pump cell.

Gas sensor and gas concentration measurement method

A gas sensor system is equipped with a first gas detection unit, and a second gas detection unit. The first and second gas detection units include a gas introduction port for introducing a gas to be measured, a measurement chamber communicating with the gas introduction port, a conversion medium (NHoxidation catalyst) arranged between the gas introduction port and the measurement chamber, and which converts a portion of a first gas type into a second gas type, and a detection device that detects the second gas type. A ratio of diffusion resistances of the first gas detection unit and the second gas detection unit is greater than or equal to 0.71 and less than or equal to 1.4.

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Obu, Japan

Yuichiro Kondo