| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for accurately detecting a particulate material such as PM.SOLUTION: The concentration detector includes: a pipe through which gas passes; a first oscillation unit for generating a first electromagnetic wave; a second oscillation unit for generating a second electromagnetic wave; a first detection unit for detecting a first transmitted wave after the first electromagnetic wave passes through the gas; a second detection unit for detecting a second transmitted wave after the second electromagnetic wave passes through the gas; and an arithmetic unit for determining the concentration of a predetermined component contained in the gas, on the basis of the first transmitted wave detected by the first detection unit and the second transmitted wave detected by the second detection unit.SELECTED DRAWING: Figure 1 |
