| 摘要 |
PURPOSE:To form an electrode which has excellent low-temp. activity and response speed and is useful for an oxygen concn. sensor of a thick film laminated type by forming a 1st electrode layer consisting of a 1st paste material on the surface of the sensor body. CONSTITUTION:The 1st electrode layer 2 is first formed of the 1st paste material mixed with solid electrolyte ceramic powder and platinum powder. The 2nd electrode layer 3 is thereafter formed of the 2nd paste material in which the platinum occupies the greater part on the surface of the 1st electrode layer. Namely, the electrode is constituted of the 1st electrode layer incorporated with the solid electrolyte ceramic powder in the part in contact with the sensor body 1 and the 2nd electrode layer 3 formed of the platinum in the greater part on the surface side. A gas to be measured passes the 2nd electrode layer 3 first. A catalytic action is surely effected in the 2nd electrode layer 3 and the diffusion resistance of oxygen decreased. The gas to be measured passes the 1st electrode layer 2 thereafter. There are many contact points between the solid electrolyte ceramic powder and the platinum powder in the 1st electrode layer 2 and the donation and reception of electrons are surely and rapidly executed. The response speed is thus improved and the electrode which is active even at a low temp. is obtd. |
