An electronic device manufacturing system includes: a gas supply; a mass flow controller (MFC) coupled to the gas supply; an inlet coupled to the MFC; an outlet; a control volume serially coupled to the inlet to receive a gas flow; and a flow restrictor serially coupled to the control volume and the outlet. A controller is adapted to allow the gas supply to flow gas through the control volume and the flow restrictor to achieve a stable pressure in the control volume, terminate the gas flow from the gas supply, and measure a rate of pressure decay in the control volume over time. A process chamber is coupled to a flow path, which is coupled to the mass flow controller, the process chamber to receive one or more process chemistries via the mass flow controller.