Sensing exhaust gas temperature is a key component in diesel after treatment systems for both control and diagnostics. Accuracy varies significantly depending upon the sensing technology and implementation in the system. Prior published work has demonstrated that resistance based temperature sensors are not able to achieve the system accuracy required for advanced diagnostics over the life of the emission system. This presentation will show that it is feasible to achieve better than �10�C end of life system accuracy by means of active thermocouple technology. Results from tests at Michigan Technological University will be used to illustrate diagnostic uncertainty related to the application of temperature sensors and a specific DOC/DPF example will be used to show the benefits of accurate temperature based diagnostics.
PresenterD. P. Culbertson, Watlow Gordon