3. Controlling the running of a column

To operate a distillation or gas scrubbing unit, you first need to know the values taken by the various parameters. This information is provided by the measuring devices, which together form the plant's control or instrumentation system. It is not possible to monitor all operating parameters at all times, so major malfunctions will be signalled to operators by audible and visual alarms, so that faults can be located quickly. If the fault persists, automatic safety devices will protect the equipment by modifying certain setpoints or shutting down the plant if there is no other solution.