Heavy duty motors and marine engines with extremely hot exhaust gas flow need to protect components in the flow path from critical overheating. Managing engine exhaust temperature is a critical task of modern engine control and after treatment control systems. Without this function, low emissions over the lifetime of the engine would not be possible. Platinum RTD temperature sensors mounted in a custom assembly with accuracies according to the IEC 60751 norm are required with the highest quality materials to operate over a temperature range of -200 °C to +1000 °C, operating in the harshest exhaust gas conditions with minimal drift.