The float-operated Shaft Encoder SE 200 was developed based on the technology of the well-known Thalimedes. The SE 200 is designed for continuous water level measurement. A float - float cable - counterweight system translates the water level change to the float pulley. The rotation caused by this is converted into an electronical signal. A measured value is being calculated via internal processing and is available via the interfaces SDI-12 and 4...20 mA. The measuring principle guarantees an especially high accuracy and resolution. The proven drift-free float principle with variable output signal can be used for the connection to external data loggers or SPS systems. The SE 200 can be programmed via serial SDI-12 interface: measuring range, output range 4...20 mA, output format, circumference of float pulley can thus be adjusted optimally to the measuring task.