Corrosion in water-carrying installation systems leads to considerable damage and consequential costs due to loss of production. In open cooling systems in particular, there is always optimally aerated water with an often very high content of dissolved salts. The natural corrosiveness of this water is usually counteracted by adding effective corrosion inhibitors. The minimization of corrosion is, among other things, a declared goal of the 42nd BImSchV to avoid rough surfaces on which biofilms can easily form with the risk of legionella multiplication.

A reliable measurement of the corrosion rate and thus the control of the effectiveness of the water treatment in water-carrying systems is therefore an essential part of maintaining operational and process safety.

Corrosion rates are usually measured by so-called corrosion coupons. These measuring strips, which are available in various metals and metal alloys, are installed in special test sections and pickled, cleaned and weighed after a period of approx. 2 to 6 months. The corrosion rate can be determined from the mass loss. The important and necessary information about the corrosion rate is then only available with a time delay of 2 to 6 months as the sum of all corrosion processes during this period.