Delphi’s diesel exhaust emissions sensor portfolio includes its ammonia sensor and a particulate matter (PM) sensor. The ammonia sensor is intended for use in diesel vehicles equipped with an SCR system (selective catalytic reduction based on urea injection), including medium- and heavy-duty diesel vehicles. It helps enable the SCR system to work at greater NOx conversion efficiencies, which allows the engine to operate with higher fuel efficiency while helping the vehicle meet new tailpipe NOx standards. It also allows manufacturers to optimize the size of the SCR catalyst and potentially reduce or eliminate a post-oxidation catalyst that would otherwise be needed to remove excess ammonia from the exhaust. Delphi claims that its ammonia sensor is the first technology that allows direct closed-loop control of the SCR process. Its new PM sensor monitors the performance of the DPF as required by increasingly rigorous standards for onboard diagnostics (OBD). The new sensor uses resistive technology to measure levels of soot in the exhaust stream after the DPF, allowing an OBD alarm to be raised when a predetermined threshold is exceeded. The technology used in the sensing element allows packaging of the sensor in Delphi's production small sensor housing with dimensions about half the size of a conventional sensor.
Booth 513 at SAE Commercial Vehicle Engineering Congress.