Efficient flue gas cleaning is used in modern power stations. A secondary method used to reduce NOx is the SCR (selective catalytic reduction) that uses NH3 for conversion of NOx to nitrogen and water. Even with high dust concentrations, high temperatures, and high gas velocities, control and efficient operation of the SCR system is ideally done in-situ, in real-time, and across the full diameter of the process duct. Our solution: the SCR Bypass System from SICK.