In fluid process liquids, e.g. In pretreatment systems (VBH) and cathodic dip painting systems (KTL) of the vehicle primer of the automotive industry, industrial baths are repeatedly contaminated (planktonic and biofilms). AdvaTec has developed an online germ monitoring system (AMoLack) to determine the bacterial concentration, which is able to determine the development of the bacterial count in the fluid phase without gaps. Especially in KTL lacquer, where conventional methods such as biolumine