The ColorPlus measures the colour/absorbance online at up to three different wavelengths in a single instrument selectable from a wide range. Turbidity can be compensated by using an appropriate wavelength. The modular design of the instrument enables to cover various applications by selecting the most suitable measuring cell. In many cases, a standard housing like e.g. Varivent® is used. Alternatively, custom-specific flow cells in different materials and designs are available. For inspecting the instrument, checking units on the basis of reference filters can easily be inserted. Operation is done intuitive using the intelligent control system SICON via touch screen technology and colour display. Values, graphs, alarm and status messages can be presented. An internal data logger allows recalling and displaying measured data from the last 32 days. A variety of analogue and digital interfaces allows smooth system integration and control.