Coriolis Meters – Limits of Applicability
Posted on October 25, 2022 Instrumentation & Equipment Design
The error in density reported by a Coriolis meter depends on the relative motion between the components. In a sand/water flow, if the sand is sufficiently fine that it will reach terminal velocity in much less than a vibration cycle, the sand and the water will move as one and an accurate density will be reported. If not, the sand (ball bearings in the demo) will not move as much as the water, masking its mass, causing the Coriolis to under-report density.
Bubbles introduce a relative motion problem entirely analogous to the issue in sand, but they also are compressible, effectively providing suspension between the motion of the tube and the liquid inside. Just as with sand, if the bubbles are sufficiently small that they move with the water and the relative motion problem goes away, but the compressibility problem isn’t affected by bubble size.
The Coriolis meter is still often the best option for difficult materials but determining the right model for a multi-phase flow requires analysis beyond what is given by manufacturer’s sizing software.