SENSOR ELEMENT AND GAS SENSOR

• Main Authors: OKAMOTO TAKU, MORI NOBUHIKO, IKOMA NOBUKAZU, OSHIMA MASAMI, NAKASONE OSAMU, FUJII YUSUKE, ITO RYO
• Format: Patent
• Language: English; Japanese
• Published: 13.10.2022
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

To precisely detect a specific oxide gas concentration and an ammonium concentration in a measured gas, and to suppress a decrease in response properties of detection of the oxide gas concentration.SOLUTION: A sensor element includes: an element body having a longitudinal direction; an inner pump electrode 22; a measurement electrode 44; a detection electrode 56; and a heater. With a longitudinal direction of the element body as a fore-and-aft direction, the inner pump electrode 22 and the measurement electrode 44 are arranged in a front side of the element body. The detection electrode 56 is arranged in a front side of the inner pump electrode 22. The detection electrode 56, the inner pump electrode 22, and the heater are disposed such that the inner pump electrode 22 becomes hotter than the detection electrode 56 when being heated by the heater. Distance A in a fore-and-aft direction between the detection electrode 56 and the inner pump electrode 22 is equal to or more than 1 mm, and distance L in a fore-and-aft direction from a gas introduction port 10 as an entrance to a measured gas circulation part to the measurement electrode 44 is equal to or less than 13 mm.SELECTED DRAWING: Figure 2 【課題】被測定ガス中の特定の酸化物ガス濃度及びアンモニア濃度を精度良く検出し且つ酸化物ガス濃度の検出の応答性の低下を抑制する。【解決手段】センサ素子は、長手方向を有する素子本体と、内側ポンプ電極２２と、測定電極４４と、検知電極５６と、ヒータと、を備える。素子本体の長手方向を前後方向として、内側ポンプ電極２２及び測定電極４４は、素子本体のうちの前側に配設されている。検知電極５６は、内側ポンプ電極２２よりも前方に配設されている。検知電極５６，内側ポンプ電極２２，及びヒータは、ヒータにより加熱されたときに内側ポンプ電極２２の方が検知電極５６よりも高温になるように配置されている。検知電極５６と内側ポンプ電極２２との前後方向の距離Ａが１ｍｍ以上であり、被測定ガス流通部の入口であるガス導入口１０から測定電極４４までの前後方向の距離Ｌが１３ｍｍ以下である。【選択図】図２