Patent ID: 7137400
Filing Date: 2006-11-21
Classification: G01F,G05D,Y10T

Abstract:
1. A system to measure a gas flow rate of a gas supplied from a mass flow controller to a process chamber via a process line, the system comprising: a. a mass flow controller; b. a process chamber; c. a process line providing a direct passage for said gas between said mass flow controller and said process chamber through a process line control valve; d. a vent line fluidly connecting to said process line at a junction between said mass flow controller and said process line control valve, and having a main vent line shut-off valve; e. a bypass loop extending between an inlet junction and a return junction that fluidly connect the bypass loop to the vent line, wherein the main vent line shut-off valve is disposed between the inlet junction and the return junction, said bypass loop comprising f. a computational control device that receives data signals from said flow detector; whereby said gas while flowing through said bypass loop provides for said measurement of said mass flow controller's gas flow rate which provides information for quantitation or for calibration of said mass flow controller.