Coriolis Flow Meters
Coriolis Flowmeters, also known as simply coriolis meters, offer a number of practical advantages which make them an ideal choice for applications in a wide variety of industries. These advantages include superior accuracy, multi-parameter measurement capability, no straight run piping requirement, and the ability to measure mass flows directly with no external pressure or temperature compensation required.
As fluids passes through oscillating parallel curved tubes, the time delay, or phase shift that occurs between the upstream and and downstream sides of the tubes is directly proportional to the mass flow rate. The frequency is directly proportional to the density of the flowing media. As flow passes an electromagnetic drive system causes the tubes to vibrate toward and away from each other at their resonant frequency caused by the tubes stiffness and their mass. A pair of Hall Effect sensors detect the potions of the tubes relative to one another at the inlet and outlet side of the parallel tubes. If no fluid is flowing through the tubes, they simply vibrate towards and away from each other in parallel and the outputs of the upstream and downstream sensors are in phase. However, as fluid begins to flow through the tubes, the Coriolis effect causes the downstream side of the loop to slightly lead the upstream side creating a slight twist on the tube. The twisting effect causes a phase shift, or time delay between the up and down stream sensors which is directly proportional to its mass flow. Inside of the meter’s display module, phase is converted to time and the time delay is then converted to a mass flow reading.
See Diagram Below:
SmartmeasurementTM offers a wide ranges of Coriolis tube geometries including the classic U shape employed by the ALCM-UT, the more popular Microbend geometry used by the ALCM-MB, the low-flow-optimized Delta, or triangle tube of the ALCM-DT, and the near straight tube geometry employed by the ALCM-ST.
Read about the other types of Flow meters: