Particulate matter detection sensor and particulate matter detection apparatus

A particulate matter detection sensor for detecting an amount of particulate matter that is included in exhaust gases, comprising:

• a conductive part that is formed into a plate shape using a conductive material having electrical resistivity that is higher than the particulate matter, with one major surface functioning as an accumulation surface on which the particulate matter accumulates;
• and
• a pair of electrodes that are formed on the accumulation surface and arranged so as to be separated from each other and to face each other,
• wherein the particulate matter detection sensor is configured to:
• apply a first voltage between the electrodes without the particulate matter being accumulated on the accumulation surface to accordingly cause a first electrical current to flow through the accumulation surface such that the first electrical current is caused to flow through the accumulation surface even if no particulate matter is accumulated on the accumulation surface;
• detect the first electrical current;
• apply a second voltage between the electrodes with the particulate matter being accumulated on the accumulation surface to accordingly cause a second electrical current to flow through the accumulation surface and the particulate matter accumulated on the accumulation surface;
• detect the second electrical current;
• and
• detect the amount of the particulate matter based on an increase in the detected second electrical current relative to the detected first electrical current.