Review: Soot (Particulate Matter) Sensor with an application to control pollution in diesel exhaust

Environmental awareness and stringent emission norms [BS-VI] made it necessary to achieve cleaner exhaust gases from diesel engines. Additional systems are required to reduce harmful components. The performance of these systems depends on sensors and controls. Reducing emission like Hydrocarbon (HC), Oxides of carbon (Cox), Oxides of Nitrogen (Nox) & particulate matter (PM) in diesel engines will be one of the greatest development challenge in future. Exhaust after treatments systems (EATS) sensors are introduced in the exhaust systems to measure and control these emissions. Particulate matter (PM) is a major pollutant from the exhaust gas, which are ultra-fine particles of size less than 100nm. PM can penetrate to cell membranes, enter into the blood, and reach the brain causing serious health problems. Hence exact measurement and control of PM emission are imperative. Diesel particulate filter is an important component of EATS. Because of stringent emission norms for diesel engines especially for PM emission, diesel particulate filters are contributing vital role for exhaust gas after treatment systems. It requires very low [0.0125g/KM] PM emission monitoring for onboard diagnostic (OBD) of DPF malfunction detection. PM sensor detects soot mass and helps to control DPF clogging through an electronic control unit. This paper aims at a study of various PM sensing methods. The study emphasizes on its significance and improving the sensing parameters for PM detection as per BS-VI norms. Review of available methods for soot sensing helps to propose an optimized and accurate way of soot sensing.