Reliable online water quality monitoring as basis for fault tolerant control

Clean data are essential for any kind of alarm or control system. To achieve the required level of data quality in online water quality monitoring, a system for fault tolerant control was developed. A modular approach was used, in which a sensor and station management module is combined with a data validation and an event detection module. The station management module assures that all relevant data, including operational data, is available and the state of the monitoring devices is fully documented. The data validation module assures that unreliable data is detected, marked as such, and that the need for sensor maintenance is timely indicated. Finally, the event detection module marks unusual system states and triggers measures and notifications. All these modules were combined into a new software package to be used on water quality monitoring stations.