FMM501D Mass Flow controller series is a analog digital compatible mode Instrument can be adjested by analog digital dispaly controller. A mass flow controller precisely controls the flow rate of gas or liquid within a system. Acting as a regulator, an MFC ensures that the correct amount of gas or liquid flows through, meeting specific process requirements. By adding an integrated or close-coupled control valve to a meter, a mass flow meter is transformed into a mass flow controller to accurately and repeatably control the mass flow rate of the supplied gases or liquids.