Process industries deal with various control systems, and fluid mass transfer control is one of them. We can use a TC9400 F/V converter to regulate the amount of liquid or gas flowing through a pipeline. A pulse train whose frequency is proportional to the rate of flow through it is generated by the flow rate detector.
This frequency is converted into a proportional analog voltage which is used to drive the valve controller by the F/V . These valve is regulated by the valve controller so that the flow is steady, even though pipeline pressure goes up and down. The actual instantaneous flow rate will be indicated by a voltmeter connected to the F/V converter output. [System’s block diagram source: Microchip Datasheet]