Requirements for industrial processes and energy conversion include high efficiency, environmental compatibility and tolerance to the type and quality of primary energy. High-temperature processes dominate in the areas mentioned. Consequently, sensors that can be used under extreme conditions form crucial components for controlling and optimizing new and existing processes. The development of sensors in line with requirements is largely determined by the materials available. This in applies particular to high-temperature sensors, hence stability and function depend on material-specific and strongly temperature-dependent processes such as the transport of the constituent elements and phase transformations. The Expert Committee therefore aims at sensor and material development for working temperatures above 350 °C, considered as a unit.