Patent ID: 7210333
Filing Date: 2007-05-01
Classification: G01N

Abstract:
1. A humidity sensor for use in an exhaust gas purifying apparatus of an internal combustion engine, comprising: a humidity-sensitive element comprising a humidity-sensitive porous ceramic layer and detection electrodes formed on the humidity-sensitive porous ceramic layer; and a heater for heating the humidity-sensitive element at a temperature of from 500–1200° C.; wherein the humidity-sensitive porous ceramic layer comprises a crystalline phase formed of at least one oxide comprising crystalline oxide grains, and a glass phase, wherein the humidity sensitive porous ceramic layer has a skeletal structure formed of the crystalline phase and the glass phase, the glass phase covering the surface of individual crystalline oxide grains to form pores in the glass phase, and wherein the humidity-sensitive porous ceramic layer contains the glass phase in an amount of 10–56 mol %.