The production of steel involves many different materials and procedures. In order to achieve a smooth, reliable production process and obtain a good product quality, the materials and procedures have to be controlled very thoroughly. One important component in the steel production is process water that is used for cooling the blastfurnace and for washing and cleaning the top gases (blast-furnace gases). After top gas purification the scrubbing water contains dissolved cyanide and the water can only be returned to the public sewage system if the cyanide concentration is below the legal limits.The ProcessLab setup described here offers a measurement and monitoring solution and provides various options for reacting to any situation. With the aid of the input/output controller, the measured analytical values are easily transferred to the process control center in the form of 4…20 mA analog signals. On the basis of these values, all further process steps are initiated and controlled automatically in the process control center.