Gas sensor

Abstract

To provide a gas sensor in which connection terminals are stably brought into contact with electrode terminal portions of a sensor element without superfluous load applied on the sensor element. A pair of element guide portionsare provided in a sleevein which a plate-like sensor elementis inserted. The pair of element guide portionsprotrude from an opening end surface on a rear end side of an axial hole, store either of widthwise opposite side ends of the sensor elementand restrain the sensor elementfrom being inclined. The sensor elementis positioned coaxially with the sleeveby the element guide portions. Electrode holdersin which electrode fitmentsare held are fitted to the element guide portionsso that the electrode fitmentsare brought into contact with electrode terminal portionsandof the sensor element. Because the positional relation between the two is decided on the basis of the element guide portions, there is no superfluous load applied on the sensor element, so that the sensor elementis prevented from being broken. In addition, pressure of contact of the electrode fitmentswith the electrode terminal portionsandof the sensor elementis kept substantially constant, so that electrically stable connection can be obtained.