Parkhurst & Wendel, LLP
Gas sensor
 Disclosed is a gas sensor comprising a sensor element for measuring a predetermined gas component contained in an introduced measurement gas, and a protective cover arranged to surround a forward end of the sensor element; the gas sensor including the sensor element having a gas-introducing port which is disposed at a forward end surface thereof for introducing the measurement gas thereinto; and the protective cover comprising an inner protective cover and an outer protective cover. The inner protective cover is provided with an opening section which makes communication with the gas-introducing port. An inner protective cover space, which is formed between the inner protective cover and the sensor element, is isolated from a communication passage which makes communication from the opening section of the inner protective cover to the gas-introducing port of the sensor element so that the measurement gas principally diffuses and flows from the opening section into the gas-introducing port of the sensor element. Accordingly, it is possible to simultaneously solve the element temperature drop and the crack formation caused by condensed water, and highly accurately measure the predetermined gas component. 
NGK Insulators, Ltd.
G
G01N
inventional
Nobukazu Yasuhiko Nobuhide
Ikoma Hamada Kato