| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure a characteristic value (for example, absorption coefficient) of an electromagnetic wave when the concentration of PM is a predetermined value such as 0 in a DPF (particulate matter collecting filter) for collecting the PM (particulate matter) in exhaust gas.SOLUTION: A DPF 1 receives exhaust gas, and collects PM in the exhaust gas. The DPF 1 has a first hole part 12 opening in a first end part on the side for receiving the exhaust gas and closing in a second end part on the opposite side of the first end part, a second hole part 14 closing in a first end part and opening in a second end part, and a third hole part 16 closing in a first end part. The first hole part and the second hole part are mutually adjacent. The mutual third hole parts are adjacent. The PM in the exhaust gas passing through a partition wall for separating the mutually adjacent first hole part and second hole part, is collected to the partition wall. A collection amount measuring device has a reference value deriving part and a collection amount deriving part. |
