MANUFACTURE OF EXHAUST GAS SENSOR

• Main Authors: KOMATSU KAZUYA, HANADA MARIKO, KUROKI YOSHIAKI
• Format: Patent
• Language: English
• Published: 07.09.1993
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To prevent a BaSnO3.3H2O bulky crystal from affecting an exhaust gas sensor by specifying the size and content of a crystallite in BaSnO3.3H2O when the crystal of BaSnO3.3H2O is decomposed to BaSnO3. CONSTITUTION:Those using a starting material containing a large quantity of BaSnO3.3H2O bulky crystals are, for example, high in a resistance value in the rich atmosphere and at a low temperature and its tolerance to a sensor temperature is narrowed. It is hard to precipitate BaSnO3.3H2O containing no bulky crystals. Then, the proportion of a crystallite with the shorter diameter of more than 25mum in BaSnO3.3H2O is limited to 5% or less with the number of particles as standard. The content of the bulky crystal is measured by observing the BaSnO3.3H2O crystal or skeleton particle after temporary sintering. BaSnO3.3H2O is a needle state crystal and can be a hexagonal crystal. The ratio of the longer diameter to the shorter diameter of the bulky crystal is smaller than a normal crystal. The particles after temporary sintering can be observed.