METHODS AND ASSEMBLIES FOR GAS FLOW RATIO CONTROL

A master controller determines a first flow setpoint for a process flow gas and/or a carrier gas flow through a first mass flow controller. The master controller obtains a back pressure setpoint of a distribution manifold and determines a second flow setpoint for the process gas flow and/or the carrier gas flow through a second mass flow controller or a back pressure controller based on the determined first flow setpoint and the obtained back pressure setpoint. The master controller controls the process gas flow and/or the carrier gas flow through the first mass flow controller to the first flow setpoint and the second mass flow controller and/or the back pressure controller to the second flow setpoint. The master controller controls the back pressure of the distribution manifold to the back pressure set point in view of a back pressure reading from a back pressure sensor of the distribution manifold.