Many traditional flowmeter technologies respond to the volumetric flow rate of the moving fluid.
Velocity-based flowmeters such as magnetic, vortex, turbine, and ultrasonic generate output signals
proportional to fluid velocity and nothing else. This means that if the fluid flowing through one of
these flowmeter types were to suddenly become denser (while still flowing by at the same number of
volumetric units per minute), the flowmeter’s response would not change at all