Henrik Schittenhelm

Particulate Matter Sensor for On Board Diagnostics (OBD) of Diesel Particulate Filters (DPF)

To meet current emission legislation standards in the EU and US modern diesel vehicles are commonly equipped with a trap for particulate matter, so called diesel particulate filter (DPF). While the required in-use monitoring (OBD) of the functional DPF efficiency can be provided by evaluating the pressure difference over the filter for current OBD-limits, it proves very difficult to meet the tightened regulations of upcoming CARB and EU legislation [1,2] with this oblique method. This calls for direct measurement of the particulate matter emissions with a novel sensor that provides sufficient accuracy and sensitivity as well as the ruggedness necessary for stable lifetime operation under exhaust-gas conditions.