Oxygen concentration detector having heat-treated support layer providing high responsivity endurance
US5472591A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1994 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Sep 14, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4075
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An oxygen concentration detector provides high durability by increasing the thermal stability of coating layers applied to an electrode face thereof. A catalyst layer is formed on an outer surface of an electrode at the analysis gas side of a partition wall made of an ion oxygen conductive ceramic for generating electromotive force according to the difference between the concentration of oxygen in the analysis gas and the concentration of oxygen in the reference gas. The catalyst layer is composed of heat resistant ceramic particles and a particulate metallic catalyst made of platinum, rhodium or the like, supported by the surface of the heat resistant ceramic particles. The catalyst layer is formed so that the catalyst is supported by the heat resistant support particles. The support particles are heat treated to grow to a particle size so that particle growth can be restrained when the support particles are exposed to the exhaust gas from an internal combustion engine. The outside of the electrode of the partition wall is covered with support particles having such heat treated large cohered catalyst particles, and good responsivity of the sensor is thereby maintained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.