The single optical fiber sensor InPro 8100 provides a wide linear measuring range - even in ranges where competing absorbance probes have long reached their saturation limit. Backscattered light technology and the use of fiber optic cables enable a sensor design with uniform, unbroken surface structure. Therefore InPro 8100 sensors are able to meet the toughest demands placed on optical sensors with respect to freedom of fouling and easy cleanability. Trouble-free transfer from laboratory/pilot operation to production level eliminates costs which normally result from required changes of measuring methods. This consistency is possible due to the use of fiber optic technology which enables compact sensor design.