Modelling of Temperature Coefficient of Resistance of a Thin Film RTD Towards Exhaust Gas Measurement Applications

Current research in the automotive industry sector focuses on the application of platinum thin film sensors for exhaust temperature measurement. The prime intention of this paper is to pioneer the design and development of Platinum/Rhodium (Pt/Rh) sensors for exhaust gas temperature measurement. The developed sensors were able to endure harsh temperature environments (up to 950° C). In addition, the Pt/Rh sensors resistivity response to temperature increase was described by a second order polynomial characteristic equation. This equation can be stored in the electronics incorporated in the engine management system. Therefore, the resistance reading of the Pt/Rh sensor in the exhaust system can be decoded as a temperature measurement.