Ngk Spark Plug Company, Limited

Takuya Saito

Satoshi Teramoto

Takeshi Kawai

Hiroshi Inagaki

Yuichi Yamada

Takao Kojima

Makoto Kume

Noboru Matsui

Shinichiro Iwama

Mitsunori Ooi

Koichi Takahashi

Takahiro Akiyama

A gas sensor including coating layers () and () of fluorine or a fluorine compound formed on the surface of a separator (), including a front separator () and a rear separator (), disposed inside a sheath (). The coating layers () and () have water impermeability and water repellency. Even in the case where moisture contained in the atmosphere within a sheath () forms dew on the surface of the separator (), the coating layers () and () prevent soaking of moisture into the separator (), to thereby secure the insulation property of the separator (). Also, the coating layers () and () having water repellency prevent a water droplet from spreading on the surface of the separator () with resultant formation of a film of water, to thereby prevent flow of leakage current via a film of water.

Gas sensor

A control apparatus for a gas sensor, wherein a microcomputer, which is connected to an oxygen sensorincluding a detection elementand a heater, detects the cooling water temperature Tw of the engine. The control apparatus determines that condensation water within the exhaust pipe is being generated when the cooling water temperature Tw is equal to or lower than 0&#xb0; C. When equal to or lower than 0&#xb0; C., the microcomputersupplies to the heaterelectrical power for maintaining the temperature of the detection elementwithin the range of 100&#xb0; C. to a splash-water-cracking generation temperature (e.g., about 300&#xb0; C.) at or above which cracking can occur in a laminated-type oxygen sensor elementdue to splash of condensation water. Electrical power is supplied to the heatersuch that a pulse signal Sh is output from the microcomputer, and the heateris pulse-driven by use of a heater electrification control circuit

Control apparatus for gas sensor

There are proposed an air/fuel ratio sensor which can detect a wide range of an air/fuel ratio and provides a simple structure, a superior mechanical strength or durability and a reduced manufacture cost, and a method of detecting the air/fuel ratio using the air/fuel ratio sensor. An air/fuel ratio sensor 1 is formed of a detecting portion 2 and a heater portion 3 laminated via a porous body 16. In the detecting portion 2, on an inner face of a plate-like solid electrolytic body 5, a reference electrode 7 is provided for controlling an oxygen gas diffusion rate, and on an outer face of the solid electrolytic body 5, a measurement electrode 6 is provided. A surface of the measurement electrode 6, on which the diffusion rate is not controlled, is covered with a protective layer 14 having an ventilation property to a degree to which the diffusion rate is not substantially controlled. A lead portion 7b of the reference electrode 7 is a porous layer which substantially controls the diffusion rate. The lead portion 7b is exposed to an exhaust gas via a connecting hole 13 which connects the lead potion 7b and the protective layer 14.

Wide range air/fuel ratio sensor having one electrochemical cell

Growing community of inventors

Kasugai, Japan

Takuya Saito