ABSTRACT

Mass and volume flow measurements become essential in many applications of practical interest. The principle involved in flow measurement may cover a wide variety of areas incorporating steady and unsteady flow of liquids, gases, two-phase media, and laminar and turbulent flows. Most of the displacement meters are basically positive-displacement meters, used for volume flow measurements. The vanes maintain continuous contact with the casing of the meter through spring loading. The accuracy of the displacement meters can be very good even at the low end of the mass/volume range. Since these are devices with moving parts, wear of the parts may alter the measurement accuracy. The conventional pitot tube or the pitot-static tube can also be used for measurement of flow rate by calibrating them for volume flow rate by locating them at a specific point in a duct. The measurement of mass flow rate rather than volume flow rate becomes essential in many practical applications.