Co-fired Platinum High Temperature Sensor Element
Abstract In recent years, initiatives for improving the fuel consumptions have been accelerated to reduce the CO2 emissions in exhaust gas from an automotive engine; as a measure against global warming. One of the known techniques to reduce CO2 emissions, is more accurate temperature measurement of the engine. For such application, sensors such as thermistors or thin-film platinum temperature sensors have been widely used for sensing exhaust gas temperature. Especially, the thin-film platinum temperature sensors were favorable because of its linearity in resistance to temperature dependensy and accuracy in temperature measurements. However, the deformation of a resistor circuit in thin-film platinum temperature sensor elements have been observed after used in high temperature. The deformation causes the resistance drifts which leads to less accurate temperature measurements. In this study, durability of the co-fired platinum temperature sensor element was examined for high temperature application. As of result, we found that the resistance drift of the co-fired platinum temperature sensor elements were smaller than that of the thin-film platinum temperature sensor elements; after storage test at 1100 °C. Thus, the co-fired platinum temperature sensor elements can be used for higher temperature sensing, which can contribute to the reduction of CO2 emission of automotive engines.