US 12,467,894 B2
Gas sensor
Yusuke Watanabe, Nagoya (JP); Shotaro Niizuma, Kasugai (JP); Toshihiro Hirakawa, Kasugai (JP); and Hayami Aota, Nagoya (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Aichi (JP)
Filed on Apr. 24, 2023, as Appl. No. 18/138,170.
Application 18/138,170 is a division of application No. 17/497,012, filed on Oct. 8, 2021, abandoned.
Claims priority of application No. 2020-171667 (JP), filed on Oct. 12, 2020.
Prior Publication US 2023/0304963 A1, Sep. 28, 2023
Int. Cl. G01N 27/407 (2006.01); G01N 27/409 (2006.01); G01N 27/41 (2006.01); G01N 33/00 (2006.01)
CPC G01N 27/4073 (2013.01) [G01N 27/4071 (2013.01); G01N 27/409 (2013.01); G01N 27/41 (2013.01); G01N 33/0037 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A gas sensor comprising:
a laminate comprising a plurality of layers including at least one layer made of a solid electrolyte;
a reference gas chamber which is formed in the laminate and in which a reference gas exists; and
a reference electrode partially exposed in the reference gas chamber, wherein
a portion which is not exposed in the reference gas chamber, of the reference electrode is sandwiched between, among the plurality of layers, a first layer and a second layer that is adjacent to the first layer,
when an area of the portion which is sandwiched between the first layer and the second layer, of the reference electrode is defined as a first area, and an area of a portion which is exposed in the reference gas chamber, of the reference electrode is defined as a second area, a ratio of the first area to the second area is 0.3 or more,
at least a part of the portion of the reference electrode which is exposed in the reference gas chamber is provided in a recess formed in the first layer, and
the reference electrode includes a protruding portion partially protruding in contact with a side surface of the reference gas chamber.