Fiercer competition and rising energy and raw material prices - the challenges facing the paper and pulp industry are substantial. In this context, it is therefore increasingly important to reduce production costs, improve product quality and meet ever more stringent environmental requirements. Not least, the production of green electricity has taken on more and more significance. By continuously analysing the dry substance in black liquor, and subsequently gaining an overview of the variations, allowing for a reduction in the margins of error for safety, the effect is twofold. Efficiency in the recovery boiler can improve massively while the energy required for the evaporation process can be drastically reduced.