| 摘要 |
PROBLEM TO BE SOLVED: To provide a soot detection device capable of highly accurately detecting an amount of soot without being affected by current associated with pumping of oxygen ions even if oxygen concentration in a target gas and the amount of soot cumulatively changes.SOLUTION: A soot detection device 1 includes: at least a pair of electrodes 21, 22 comprising a first detection electrode 22 located on a surface of an oxygen-ion-conductive solid electrolyte body 4 facing a target gas space 11 and a first reference electrode 21 located on the other surface of the oxygen-ion-conductive solid electrolyte body 4 facing a reference gas space 51; a first electrochemical cell 2 for supplying oxygen to oxidize soot on the electrode 22; and heating means 9 for heating the solid electrolyte body 4. Voltage is controlled such that voltage Vbetween the electrode 22 and the electrode 21 matches a threshold voltage value Vcorresponding to a situation where no soot is accumulated, thereby supplying oxygen from the electrode 21 to the electrode 22 to oxidize the soot accumulated on the electrode 22. The amount of soot accumulated on the electrode 22 is detected from an oxygen ion current signal I flowing through the electrochemical cell 2 at that time. |
