Venturi tube /vɛnˈtʊri tub / Italian, named after the scientist G. Venturi (1746-1822)], Venturi flow meter is a device that measures the speed or flow rate of a liquid, steam or gas by pressure difference. Since the pressure loss in W.t. less than that in the measuring diaphragm and nozzles, it is used in places where large pressure losses are not allowed.
Ex: Vanadium produced as the main product from primary ore represents 17% of the world production of vanadium.