Mass-volume flowmeter

A method for measuring flow rate of fluid comprising in combination:

• a) bifurcating a fluid flow to be measured into two flow streams respectively moving through two flow passages;
• b) at least partially obstructing at least one of said two flow passages by a flow obstructing member experiencing fluid dynamic force of the fluid flow, said flow obstructing member including a bias force tending to increase the degree of obstruction of the fluid flow through said at least one of the two flow passages, wherein the fluid dynamic force experienced by said flow obstructing member tends to decrease the degree of obstruction of the fluid flow through said at least one of the two flow passages;
• c) obtaining a first signal representing mass flow rate of the fluid moving through one of the two flow passages, and a second signal representing mass flow rate of the fluid moving through the other of the two flow passages;
• and
• d) determining volume flow rate of the fluid moving through the two flow passages as a function of said first and second signals and ratio between said signals.

An apparatus for measuring flow rate of fluid comprising in combination:

• a) a body including a first and second flow passages;
• b) a flow obstructing member at least partially obstructing at least one of said first and second flow passages, said flow obstructing member including a bias force means tending to increase the degree of obstruction of the fluid flow through said at least one flow passage, wherein fluid dynamic force exerted on said flow obstructing member by the fluid moving through said apparatus tends to decrease the degree of obstruction of the fluid flow through said at least one flow passage;
• c) means for obtaining first signal representing volume flow rate of the fluid moving through said first flow passage, and a second signal representing volume flow rate of the fluid moving through said second flow passage;
• and
• d) means for determining mass flow rate of the fluid moving through said apparatus as a function of said first and second signals and ratio between said first and second signals.

An apparatus for measuring flow rate of fluid comprising in combination:

• a) a body including a first and second flow passages;
• b) a flow obstructing member at least partially obstructing at least one of said first and second flow passages, said flow obstructing member including a bias force means tending to increase the degree of obstruction of the fluid flow through said at least one flow passage, wherein fluid dynamic force exerted on said flow obstructing member by the fluid moving through said apparatus tends to decrease the degree of obstruction of the fluid flow through said at least one flow passage;
• c) means for obtaining first signal representing mass flow rate of the fluid moving through said first flow passage, and a second signal representing mass flow rate of the fluid moving through said second flow passage;
• and
• d) means for determining volume flow rate of the fluid moving through said apparatus as a function of said first and second signals and ratio between said first and second signals.