What are the primary components and operating principle of a Coriolis flow meter?

The primary components of a Coriolis flow meter are one or more vibrating tubes, typically U-shaped or straight, through which the fluid flows, and sensors to measure the vibration characteristics of the tubes. The operating principle relies on the Coriolis effect, which is the apparent deflection of a moving object when viewed from a rotating reference frame. In a Coriolis flow meter, the vibrating tubes are forced to oscillate at a specific frequency. When fluid flows through the vibrating tubes, it experiences the Coriolis force, which is proportional to the mass flow rate of the fluid. This force causes the tubes to twist or deflect slightly. Sensors, typically magnetic pick-offs or optical sensors, measure the amount of twist or deflection. The phase difference between the vibrations at the inlet and outlet of the tube is directly proportional to the mass flow rate. The meter's electronics then convert this phase difference into a mass flow rate reading. Coriolis flow meters offer several advantages over other types of flow meters, including high accuracy, direct mass flow measurement (independent of fluid properties like density and viscosity), and the ability to measure the density of the fluid. Because the meter measures mass flow directly, it doesn't require compensation for changes in fluid temperature or pressure. An example application is measuring the flow of crude oil in a pipeline, where the density and viscosity of the oil can vary significantly. The Coriolis meter accurately measures the mass flow regardless of these variations.