How does a positive displacement water meter work?

How does a positive displacement flow meter work? Positive Displacement flow meters are the only flow measuring technology to directly measure the volume of fluid that passes though the flow meter. It achieves this by trapping pockets of fluid between rotating components housed within a high precision chamber.Click to see full answer. In this way, how does a positive displacement meter work?Positive displacement (PD) flow meters measure the volumetric flow rate of a moving fluid or gas by dividing the media into fixed, metered volumes (finite increments or volumes of the fluid). With appropriate pressure and temperature compensation, the mass flow rate can be accurately determined.Secondly, how does the variable area meter work? The Variable Area Flowmeter is an instrument for measuring the flow of liquids and gases in pipelines. It includes a vertical tube through which the fluid flows whose diameter increases from the bottom to the top and a float which can move vertically in the tube. The position of the float is a measure of the flowrate. Also know, how does a piston flow meter work? Piston flow meters are ideal for low viscosity fluids due to the tight tolerances & fits they use. They operate by a piston moving within a chamber of known volume. When fluid passes into this chamber, the piston displaces an exact volume of liquid. Piston meters are great for low volume flow measurements.What does a Coriolis meter measure? Volume flow versus mass flow Coriolis flow meters measure real mass flow, whereas thermal mass flow meters are dependent of the physical properties of the fluid. Volumetric measuring devices, such as variable area meters and turbine flow meters, are unable to distinguish temperature or pressure changes.