Patent ID: 7607362

Claim:
A flowmeter for determining a flow rate of a fluid having a plurality of state properties, the flowmeter comprising: a housing conduit having an inlet, an outlet, and a cylindrical chamber, the cylindrical chamber being interposed between the inlet and the outlet; an impeller assembly positioned within the cylindrical chamber for rotation, wherein the impeller assembly is operably coupled to a controller to facilitate the rotation of the impeller assembly at a variable speed such that a pressure differential of the fluid between the inlet and the outlet varies between a first pressure value and a second pressure value in response to the variable speed of the impeller assembly; and a pressure sensor fluidly coupled to the housing conduit and configured to measure the pressure differential of the fluid at a preselected pressure value that is between the first and second pressure values to determine the flow rate of the fluid independent of at least one state property of the fluid.