Coriolis and mass flow: A dynamic duo
By: Premier Control Technologies
You may have heard of the Coriolis effect, a term commonly used to explain why hurricanes, tornadoes, and typhoons spin counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Behind this phenomenon is the Coriolis force, a fictitious force responsible for the apparent deflection of an object moving within a rotating frame of reference. In the weather example, air traveling through the atmosphere is directed to either the right or left (depending on the hemisphere) and determines the spin direction of weather bodies.
While Newtonian laws of motion sufficiently describe the motion of objects within a stationary frame, they require an additional correction factor provided by the fictitious Coriolis force to describe motion within a rotating frame of reference. This is necessary because the object isn't physically tethered to the frame of reference, or coordinate system, which is used to characterize its motion. So, an object will appear to be deflected from the initial path as the frame of reference rotates beneath it.
The difference between the intended and actual path is measurable as a deflection resulting from the Coriolis effect.
How does Alicat's CODA-series work?
The CODA-series of mass flow meters and controllers utilizes the Coriolis operating principle and uses the single tube setup described above. The measurement process is as follows: