In dip processes such as electrophoretic coating or the dip-spin process of zinc flake coating dip tanks and coating baths of various dimensions are used, depending on the objects to be coated. The coating substances - also known as bath material - are located within the respective tanks. With the progression of coating, bath material is removed from the tank, with the result that coating material needs to be replaced to compensate.

The theoretical one-time material consumption of the entire bath material is referred to as turnover. Turnover is of great significance, as the replacement speed of the bath material as a result of compensation has an enormous influence on bath stability and ultimately on the quality of the coating.