In recent years, TOC analysis has become accepted in the industry as the standard method and the only reliable online method used to determine contamination in waters, to control processes, to prevent product losses and to minimize waste. It is especially important to monitor this parameter in applications such as condensate return water, boiler/feed water, etc. In boiler/feed water and in industrial steam generating systems, carbonic acid corrosion of condensate lines is often a serious problem. Depending on the application type, analysis of only one parameter (e.g., TC) is generally not sufficient to make any useful process decisions. Multiple-parameter analysis (TOC, TC, TIC, VOC etc.), as carried out in the Hach BioTector B3500c analyzer, is proven to be more useful and always superior to single-parameter analysis in the industry.