Sensor, actuator and plant validation

Effective production requires functional unit processes, under stable control with credible sensed data and precise actuation. Validation of these components is not just an aid to safe operation, but can also enhance the availability of the plant. Cost-effective validation uses standard metrics for the intercommunication of results via Fieldbus and starts at the sensor and actuator level: the paper gives examples from mass-flow metering, temperature and DOx sensing, and from flow actuation. In particular, greater availability comes from limp-home features which provide a degree of operability even in the presence of faults. This can be achieved at the device level, or via retuning of the loop´s PID regulator, or by manipulating the constraints supplied to a model-predictive controller, resulting in loop reconfiguration