Abstract: A flow measurement system is provided, which is configured to receive multiple flow rates; retrieve multiple physical properties for multiple pure gases; estimate multiple physical properties for a gas mixture; estimate multiple flow parameters for multiple channels of a flow splitter using a mathematical model, multiple physical properties for the gas mixture, and multiple pressure values from pressure sensors of multiple channels; and estimate multiple flow splits using multiple flow parameters for the multiple channels of the flow splitter.

Abstract: A flow restrictor is provided, comprising a first sheet including a flow passage, and a second sheet stacked on the first sheet. A hole is provided in a center of the second sheet. The flow passage includes a groove cut into a surface of the first sheet that communicates with an expansion zone at a peripheral area of the first sheet. A peripheral edge of the second sheet contacts the first sheet in the expansion zone between an inner diameter and an outer diameter of the expansion zone.