US Patent 7862649 Particulate matter detection device and particulate matter detection method

A particulate matter detection device includes a collection electrode that collects the particulate matter, a discharge electrode that allows a corona discharge to occur when a voltage is applied between the collection electrode and the discharge electrode, a measurement electrode, the impedance between the collection electrode and the measurement electrode changing when the collection electrode has collected the particulate matter, and a measurement section that detects a change in the impedance between the collection electrode and the measurement electrode, the particulate matter detection device detecting the particulate matter by charging the particulate matter contained in the gas by utilizing the corona discharge, collecting the charged particulate matter by the collection electrode by utilizing an electrostatic force, and detecting a change in the impedance between the collection electrode that has collected the particulate matter and the measurement electrode using the measurement section.