The ColorPlus measures the colour/absorbance online at up to three different wavelengths. The bypass measuring cell has been specifically designed for applications within the water industry. Depending on the configuration it allows measuring DOC (UV absorption) and colour (Hazen) simultaneously and to compensate turbidity. Soiling of the flow cell is measured by means of a compensation glass in the interior of the flow cell. The effect of cell soiling is greatly reduced internally; constant and precise measured values are guaranteed. The user is alerted if the cell has to be cleaned. The cover of the flow cell can be opened without tools and allows simple access for cleaning the flow cell. 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.