| 摘要 |
The present invention is provided with: a first PM sensor 10A that is provided with a first sensor filter 31A that has a plurality of first cells that are demarcated by porous partitioning walls and that capture PM in exhaust gas that flows into a filter 220, and with a first electrode pair 32A, 33A that forms a capacitor and is arranged so as to sandwich the first cells, and that is disposed nearer to the exhaust-gas upstream side than the filter; a second PM sensor 10B that is provided with a second sensor filter 31B that has a plurality of second cells that are demarcated by porous partitioning walls and that capture PM in exhaust gas discharged from the filter, and with a second electrode pair 32B, 33B that forms a capacitor and is arranged so as to sandwich the second cells, and that is disposed nearer to the exhaust-gas downstream side than the filter; and a filter condition determination unit that acquires the PM capturing efficiency of the filter on the basis of a first capacitance between the first electrode pair and a second capacitance between the second electrode pair. |
