How do mass flow controllers work?

Mass flow controllers (MFCs) regulate the flow of gases or liquids in a system by measuring and controlling the mass flow rate. They typically use a sensor to detect the flow rate, often through thermal or pressure differential methods, and compare it to a setpoint. Based on this comparison, a control algorithm adjusts a valve to maintain the desired flow rate. This ensures precise control of the process, making MFCs essential in applications like semiconductor manufacturing and chemical processing.