Why a flowing fluid makes the tube twist
A Coriolis meter drives one or more bent tubes into a small, rapid vibration. When fluid moves through a vibrating curve, its momentum resists the tube’s changing motion. The flowing fluid pushes back on different parts of the curve at different moments, producing a slight twist. Sensors detect that motion, often by comparing the timing of vibrations at two points on the tube.
With no flow, those points move in step. As flow increases, the measured timing difference grows. The meter uses that change to calculate mass flow: how much matter passes through per unit of time, rather than how much space it occupies.
Why mass flow matters
A volume measurement can shift when a fluid warms or cools. Liquids expand or contract, and gases can change volume substantially with temperature and pressure. A meter that reports only volume may therefore give a different reading even when the same amount of material is moving through the pipe.
Mass flow avoids that particular ambiguity. The amount of material remains the same even if its density—and thus its volume—changes. That makes Coriolis meters useful where a process needs to control or account for the actual quantity of a fluid, such as dosing ingredients or tracking fuel.
The vibrating tube also responds to the fluid’s density, which meters can infer from its vibration behavior. But the central measurement comes from the flow-induced twist: a tiny mechanical reaction that lets the instrument weigh a moving stream without stopping it.
