公开(公告)号：US20190383765A1

公开(公告)日：2019-12-19

申请号：US16438533

申请日：2019-06-12

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO

IPC: G01N27/409 ,  G01N27/41 ,  G01N27/407 ,  G01N27/416

Abstract: In a gas sensor configured to measure the concentrations of a plurality of components in the presence of oxygen, in the interior of a structural body made from an oxygen ion conductive solid electrolyte, a preliminary chamber having a mixed potential electrode, an oxygen concentration adjustment chamber having a main pump electrode, and a measurement chamber having a measurement electrode are formed in a manner communicating in this order. While oxygen within the gas to be measured is being discharged by the main pump electrode and the measurement electrode, the NH3 concentration within the gas to be measured is measured by a mixed potential V0 of the mixed potential electrode.

公开(公告)号：US20190154628A1

公开(公告)日：2019-05-23

申请号：US16253243

申请日：2019-01-22

Applicant: NGK INSULATORS, LTD.

Inventor： Yuki NAKAYAMA ,  Noriko HIRATA ,  Taku OKAMOTO ,  Kosuke MONNA

IPC: G01N27/41 ,  G01N27/406 ,  G01N27/407

Abstract: A sensor element includes: a sensing cell including a sensing electrode and a reference electrode; an oxygen pump cell configured to pump out oxygen in an internal space when a predetermined voltage is applied between an inner side pump electrode formed facing to the internal space and an outer side pump electrode formed on an outer surface of the sensor element; and a heater capable of heating the sensing cell and the oxygen pump cell. The concentration of a target gas component in measurement gas is specified based on a sensor output generated at the sensing cell and a pump current at the oxygen pump cell while the heater heats the sensing cell to a temperature of 400° C. to 600° C. and heats the oxygen pump cell to a temperature of 580° C. to 850° C. determined in accordance with a diffusion resistance provided to the measurement gas by a gas introduction part.

公开(公告)号：US20180356364A1

公开(公告)日：2018-12-13

申请号：US15996560

申请日：2018-06-04

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Yuki NAKAYAMA ,  Soichiro YOSHIDA

IPC: G01N27/416 ,  G01N27/04

Abstract: A method of inspecting an electrode provided in a gas sensor element includes the steps of: producing, in advance, a calibration curve representing a relation between an Au maldistribution degree defined based on a ratio of an area of a portion at which Au is exposed on a noble metal particle surface and calculated from a result of XPS or AES analysis on an inspection target electrode, and a predetermined alternative maldistribution degree index correlated with the Au maldistribution degree and acquired in a non-destructive manner from the gas sensor element heated to a predetermined temperature; acquiring a value of the alternative maldistribution degree index for the inspection target electrode of the gas sensor element while the gas sensor element is heated to the predetermined temperature; and determining whether the Au maldistribution degree satisfies a predetermined standard based on the calibration curve and the acquired inspection value.

公开(公告)号：US20180112582A1

公开(公告)日：2018-04-26

申请号：US15786835

申请日：2017-10-18

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Yoshinobu NAKADA ,  Kosuke MONNA

IPC: F01N11/00 ,  G01N33/00 ,  G01N27/416

CPC classification number: F01N11/007 ,  F01N3/2066 ,  F01N2560/021 ,  F01N2560/025 ,  F01N2560/20 ,  F01N2610/02 ,  G01N27/4162 ,  G01N27/419 ,  G01N33/0054 ,  Y02A50/246 ,  Y02T10/24

Abstract: An apparatus for measuring ammonia concentration measures ammonia concentration in a target gas with a sensor element including a mixed potential cell. The apparatus for measuring ammonia concentration includes an electromotive force acquisition section, an oxygen concentration acquisition section, and an ammonia concentration derivation section. The ammonia concentration derivation section derives the ammonia concentration in the target gas from the relationship represented by formula (1): EMF=α loga(pNH3)−β logb(pO2)+γ logc(pNH3)×logd(pO2)+B  (1) (where EMF: an electromotive force of the mixed potential cell, α, β, γ, and B: constants (provided that each of α, β, and γ≠0), a, b, c, and d: any base (provided that each of a, b, c, and d≠1, and each of a, b, c, and d>0), pNH3: the ammonia concentration in the target gas, and pO2: the oxygen concentration in the target gas).

公开(公告)号：US20170276051A1

公开(公告)日：2017-09-28

申请号：US15453037

申请日：2017-03-08

Applicant: NGK INSULATORS, LTD.

Inventor： Kosuke MONNA ,  Taku OKAMOTO ,  Takayuki SAKURAI ,  Noriko HIRATA

IPC: F01N11/00 ,  B01D53/94 ,  F01N3/08 ,  G01M15/10 ,  F01N3/10

CPC classification number: F01N11/007 ,  B01D53/944 ,  F01N3/0814 ,  F01N3/0835 ,  F01N3/0857 ,  F01N3/103 ,  F01N11/00 ,  F01N2550/02 ,  F01N2550/03 ,  F01N2560/023 ,  F01N2560/06 ,  F01N2570/10 ,  F01N2570/12 ,  F01N2900/1402 ,  F01N2900/1404 ,  G01M15/102 ,  G01M15/104 ,  Y02T10/47

Abstract: Provided is a method for accurately diagnosing a degree of degradation of an oxidation catalyst. A target gas detecting element configured to output an electromotive force corresponding to a concentration of a target gas is provided downstream of a catalyst in an exhaust path of an internal combustion engine. A sum of change amounts of an electromotive force in a time-variable profile thereof after the introduction of a gas atmosphere for diagnosis into the catalyst is set as a diagnosis index value. The gas atmosphere has been intentionally created in the engine and includes a target gas having a concentration higher than the concentration of a target gas during a steady operation state of the engine. The index value is then compared with a threshold corresponding to the temperature of the catalyst to diagnosis whether degradation exceeding an acceptable degree has occurred in the catalyst.

公开(公告)号：US20160223487A1

公开(公告)日：2016-08-04

申请号：US14995510

申请日：2016-01-14

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Osamu NAKASONE ,  Yuki NAKAYAMA

IPC: G01N27/407

Abstract: Provided is a gas sensor capable of accurately obtaining the concentrations of water vapor and carbon dioxide in up to a high concentration range. The diffusion resistance from a gas inlet to a first internal space is 370/cm to 100/cm. The oxygen partial pressure of the first internal space is adjusted to 10−12 atm to 10−30 atm. A first measuring pumping cell adjusts the oxygen partial pressure of a second internal space such that hydrogen generated by the decomposition of water vapor selectively burns. A second measuring pumping cell adjusts the oxygen partial pressure on the surface of a second measuring internal electrode such that all of the carbon monoxide generated by the decomposition of carbon dioxide burns on the surface. The concentrations of water vapor and carbon dioxide are based on the magnitude of a current flowing between the first or second measuring internal electrode and the external electrode.

Abstract translation: 提供能够精确地获得高浓度范围内的水蒸汽和二氧化碳浓度的气体传感器。 从气体入口到第一内部空间的扩散阻力为370 / cm〜100 / cm。 将第一内部空间的氧分压调节至10-12atm至10-30atm。 第一测量泵浦单元调节第二内部空间的氧分压，使得由水蒸气分解产生的氢气选择性地燃烧。 第二测量泵浦单元调节第二测量内部电极的表面上的氧分压，使得由二氧化碳分解产生的所有一氧化碳在表面上燃烧。 水蒸气和二氧化碳的浓度基于在第一或第二测量内部电极和外部电极之间流动的电流的大小。

公开(公告)号：US20160216229A1

公开(公告)日：2016-07-28

申请号：US14995362

申请日：2016-01-14

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Osamu NAKASONE ,  Yuki NAKAYAMA

IPC: G01N27/419 ,  G01N27/41

Abstract: Provided is a gas sensor capable of accurately obtaining the concentration of water vapor of a measurement gas. A main pumping cell adjusts an oxygen partial pressure of a first internal space such that all of the water vapor of a measurement gas is decomposed in the first internal space. A measuring pumping cell adjusts an oxygen partial pressure of a second internal space such that hydrogen generated by the decomposition of water vapor selectively burns. A metal component of a measuring internal electrode contains an alloy of gold and a noble metal other than gold. A gold abundance ratio of the metal component on the surface of the measuring internal electrode is 25 at % or higher. The concentration of water vapor is identified based on the magnitude of a current flowing between the measuring internal electrode and an external electrode.

Abstract translation: 提供能够精确地获得测定气体的水蒸气浓度的气体传感器。 主泵送单元调节第一内部空间的氧分压，使得测量气体的所有水蒸气在第一内部空间中分解。 测量泵送单元调节第二内部空间的氧分压，使得由水蒸汽分解产生的氢气选择性地燃烧。 测量内部电极的金属成分含有金和金以外的贵金属的合金。 测量内部电极的表面上的金属成分的金丰度比为25at％以上。 基于在测量内部电极和外部电极之间流动的电流的大小来识别水蒸汽的浓度。