| abstract |
A gas sensor 100 is provided with: a gas detection section 101 having a light source 102 and a detector; and a gas passage section 130, which has a first end section 144, a second end section 146, and a hollow section 148, said first end section 144 being disposed on the gas detection section 101 side, and said second end section 146 being disposed on the gas space side. The hollow section 148 has a shape wherein a flow passage cross-sectional area N is reduced toward the first end section 144 side from the second end section 146 side. The gas passage section 130 has: a member 152 that partitions the hollow section 148 into at least a first region 148a and a second region 148b; a gas inflow port 154 that connects the gas space and the first region 148a to each other; and a gas outflow port 156 that connects the second region 148b and the gas space to each other. A gas to be detected flows into the hollow section 148 from the gas inflow port 154, flows in the first region 148a, and reaches the gas detection section 101, and the gas in the gas detection section 101 flows in the second region 148b, and flows out to the gas space from the gas outflow port 156. |