Different turbidity ranges require differing optimum measuring techniques. The forward scattered light technique of the InPro8400 sensor series enables measurements even in liquids that appear clear to the human eye. The combined forward/900 scattered light technique of the InPro8500 sensor series makes it possible to distinguish between turbidity caused by colloidal particles or larger particles. With a variety of different process connections and line sizes, these flow-through sensors can be installed in main pipes or in a bypass line. The Trb 8300 F/S transmitter enables quick start-up and operation with the full-text menu guide in three selectable languages. Sensor diagnostic features provide information on sensor performance, reducing maintenance time.