Patent ID: 8010303

Claim:
A fluid flow controller comprising: a flow sensor comprising a bypass with a plurality of bypass tubes, a sensor conduit in fluid communication with the bypass, a sensor assembly operatively coupled to the sensor conduit to generate a measured signal representative of a flow rate of a fluid through the sensor conduit; a processor operatively configured to receive the measured signal and to generate a flow rate representation based at least partially on the measured signal and a characteristic function of the flow sensor, the characteristic function at least partially defined by a dynamic pressure of fluid flowing through the bypass; wherein the characteristic function is represented by a relationship defined during calibration of the flow sensor at a plurality of flow rates with at least one calibration fluid: Q Δ ⁢ ⁢ P = G ⁡ ( Re ⁢ D L ) ; where Q is a dynamic pressure of a bypass of the flow sensor, ΔP is the overall pressure differential, Re is a Reynolds number of the fluid flowing through the bypass, D is the inside diameter of bypass tubes in the bypass, and L is the length of the bypass tubes; and a flow regulator fluidly connected to the flow sensor and configured to receive a control signal from the processor that is at least partially based on the flow rate representation and a desired fluid flow.