Apparatus for detecting particulate matter and correction method of apparatus for detecting particulate matter

An apparatus for detecting particulate matter that detects particulate matter within a gas to be measured,

• wherein the apparatus includes a particulate matter detection sensor, a field generation power unit and a measuring section,
• the particulate matter detection sensor includes at least
• a sensor element that has the detecting element in which an electrode for collecting or an electrode provided separately from the electrode for collecting is used as a sensing electrode that detects an electrical characteristic that changes depending on the amount of particulate matter collected in the detecting element, the electrode for collecting being to collect the particulate matter within the gas to be measured in a detecting element using attractive force generated by an electric field generated by the field generation power unit;
• a cover body that protects the sensor element;
• and
• a housing that places the detecting element in the gas to be measured,
• the measuring section measures the electrical characteristic that changes depending on the amount of particulate matter within the gas to be measured that is collected in the detecting element,
• wherein the apparatus for detecting particulate matter includes an applied voltage correction means,
• a dead mass is a value until output is produced in relation to a gas to be measured for calibration containing a known amount of particulate matter becomes a predetermined threshold or more,
• when the dead mass is greater than a dead mass of a particulate matter detection sensor for calibration serving as reference, the applied voltage correction means holds the voltage applied by the field generation power unit at a predetermined applied voltage value and maintains the field strength to reduce the dead mass;
• and
• when the dead mass is less than the dead mass of the particulate matter detection sensor for calibration serving as reference, the applied voltage correction means sets the voltage applied by the field generation power unit to be lower than a predetermined lower threshold applied voltage or higher than a predetermined upper threshold applied voltage, and corrects the field strength to increase the dead mass.