A non-invasive type of flow meter used to measure the mass flow of a fluid through a pipeline. It is based on the Coriolis effect and involves diversionary loops of pipe through which the fluid passes. As the fluid moves through the loop, the fluid momentum changes and rotates, exerting a force on the loop causing it to twist and vibrate. The extent of the twisting and vibration effect gives an indication of the rate of mass flow. It is named after French physicist Gaspard de Coriolis (1742–1843) who first used the term for describing the movement of fluids in rotating systems.