There are applications in which it is imperative to maintain constant flow rates. Effects such as pressure or temperature fluctuations, as well as density or viscosity changes in the medium can change flow rates and as a result cause problems in processes. Particularly on the use of aggressive gaseous media or in applications in an aggressive environment it was very difficult in the past to ensure constant flow rates. With the newly developed intelligent control unit, errors can now also be detected automatically under difficult conditions and reliably regulated. The control unit FC4 comprises several components: the flow meter, a photoelectric switch, a precision metering valve with electrical actuator and the digital three-point controller with microprocessor. During the development of the new control unit, only fittings and components with high media resistance and that are highly suitable for use with aggressive media were used. Application-specific requirements can be taken into account; integrated fittings made of various high quality plastics are available depending on the application. As a result the control unit is optimally suited for applications with aggressive gaseous media.
The principle of operation is simple: The required flow rate is set by adjusting the photoelectric switch on the flow meter measuring tube. If the flow rate varies, the variation is signalled to the controller by the photoelectric switch; the controller immediately triggers an automatic correction via the upstream precision metering valve. Furthermore, special buttons on the controller make it possible for the user to quickly intervene manually. The control unit FC4 is suitable for flow rate ranges from 4 – 1.600 l/h with air and 2,5 – 100 l/h with water.