| 摘要 |
PURPOSE:To provide an electrochemical gas sensor which prevents failure in the output resulting from excessive water leak at a sensor element accommodated in the internal space by precluding such excessive water leaking, permitting the gas to be sensed to permeate a solid electrolyte film and reach the working electrode, and causing an electrochemical electrode reaction at the working electrode. CONSTITUTION:An electrochemical gas sensor concerned includes a housing 30 and a water reservoir 40 installed at the housing 30 with a bulkhead 20 interposed, wherein the housing 30 is equipped with a vent 34 to introduce a gas to be sensed and an internal space 35 in which the gas is dispersed. The internal space 35 accommodates a sensor element 10, while the bulkhead 20 is provided with a communication hole 36 which puts the internal space 35 in communication with the water reservoir 40. The sensor element 10 is composed of a working electrode 70 and its counter-electrode 90 and also a solid electrolyte film 110 which encloses these electrodes and becomes electrolytic in the condition containing water. A diaphragm 120 capable of expanding and contracting is provided on the wall 60 of the water reservoir 40. |
