| 摘要 |
PROBLEM TO BE SOLVED: To keep a specified detection capacity over a long period of time even in a gas to be inspected containing solid particles and fluctuated in temp. and flow velocity by providing a detection element on the surface of a plate- shaped detection substrate. SOLUTION: A detection substrate 1 has an elongated rectangular plate shape and is composed of a partially stabilized zirconia solid electrolyte and a detection element 2 having a heating element built therein is provided to one end of the substrate 1. When the stream of exhaust gas being a gas to be inspected flows, the stream of the exhaust gas within an exhaust pipe 8 is cut off by a protective metal fitting 7 and a part thereof flows in from an outer peripheral surface gas flow port 31 and the greater part of the inflow gas flows out of the outer peripheral surface gas flow port 32 on the opposite side and only a part thereof flows out of a bottom surface gas flow port 34. By this constitution, since the stream of the exhaust gas in the metal fitting 7 passes through the place separated from the element 2, the greater part of solid particles, especially, heavy matter such as a metal element is carried on flow velocity to be discharged from the flow port 32 to be prevented from colliding with and adhering to the surface of the element 2. |
