US 10,520,466 B2Granted

Gas sensor

AssigneeNGK Insulators, Ltd.

InventorsTaku Okamoto, Yuki Nakayama, Noriko Hirata

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Abstract

A gas sensor that is unlikely to have Au evaporation from an external electrode even when used under a high temperature atmosphere is provided. The gas sensor includes a sensor element mainly made of an oxygen-ion conductive solid electrolyte; an external electrode provided on the sensor element and containing a Pt—Au alloy; and an electrode evaporation preventing film provided on the sensor element while being insulated from the sensor element and separated from the external electrode, and made of Au or a Pt—Au alloy having an Au composition ratio not smaller than an Au composition ratio of the Pt—Au alloy contained in the external electrode. A protection cover is provided so that at least part of the sensor element, at which the external electrode and the electrode evaporation preventing film is positioned, is inside the protection cover, and so that a measurement gas is introduced inside the protection cover.

Claims10

Dependent claims

A gas sensor for measuring a concentration of a predetermined gas component in a measurement gas, comprising:

a sensor element mainly made of an oxygen-ion conductive solid electrolyte;
at least one external electrode provided on said sensor element and containing a Pt—Au alloy;
an insulating layer formed on said sensor element and separated from said at least one external electrode;
an electrode evaporation preventing film laminated on said insulating layer and separated from said at least one external electrode, and made of Au or a Pt—Au alloy having an Au composition ratio not smaller than an Au composition ratio of the Pt—Au alloy contained in said at least one external electrode;
and
a protection cover provided so that at least part of said sensor element is positioned inside said protection cover and said measurement gas is introduced inside said protection cover, said at least one external electrode and said electrode evaporation preventing film being provided on said at least part of said sensor element.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/708,431Filed 19 Sep 2017
Priority: JP 2016-18516123 Sep 2016
Published: US 2018/0088074 A129 Mar 2018
Granted: 31 Dec 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01N 27/4077
For investigating or analysing gases: means for protecting the electrolyte or the electrodes
G01N 27/4071
For investigating or analysing gases: using sensor elements of laminated structure
G01N 27/4075
For investigating or analysing gases: composition or fabrication of the electrodes and coatings thereon, e.g. catalysts
G01N 27/4076
Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts: reference electrodes or reference mixtures