Ngk Spark Plug Company, Limited

Seiji Ohya

Koji Shiotani

Tomohiro Wakazono

Kenji Kato

Hisashi Sasaki

Takashi Nakao

A gas sensor including a gas sensor element having a first measurement chamber (); a first pumping cell (); a second measurement chamber () into which a gas to be measured having a controlled oxygen partial pressure is introduced; and a second pumping cell () having a second inner pump electrode () and a second counterpart electrode () pump electrode configured to detect a specific gas component. The second inner pump electrode is made of a material that contains, as a principal ingredient, two kinds of Pt particles having different particle sizes and whose particle size ratio measured by a sedimentation particle-size distribution ranges from 1.75 to 14.2. A mixing ratio between large Pt particles and small Pt particles has a mass ratio of 10/90 to 50/50. A 10 kHz-1 Hz resistance value across the second pumping cell at 600&#xb0; C. is 150&#x3a9; or less.

Gas sensor and method for manufacturing the same

A gas sensor () has a gas sensor element () including a first measurement chamber (); a first pumping cell () having a first interior pump electrode () and its counterpart electrode (); a second measurement chamber (); a second pumping cell () that has a second interior pump electrode (); and a beater (). The heater () has a lead section (); a first resistance portion () having a higher resistance than the lead portion (); and a main heating portion () having a second resistance portion () having a higher resistance than the first resistance portion () disposed at a leading end side in a longitudinal direction relative to a leading end of the first resistance portion (). The second interior pump electrode () is located within the first resistance portion () in the longitudinal direction.

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Aichi, Japan

Seiji Ohya