For a Coriolis meter, the tubing is oscillated at what angle to the flow?

• A. At a right angle
• B. Parallel
• C. Coincident with flow
• D. At 45 degrees

Answer: (A)

In a Coriolis meter, the tubes are driven to vibrate in a direction that is perpendicular to the fluid flow. This transverse (right-angle) vibration is what allows the Coriolis effect to couple into the tube as the fluid moves through it. The flowing fluid through the vibrating tube causes a phase shift or twist that the sensors detect, and that shift is proportional to the mass flow rate.

If the tube were oscillated parallel to the flow, there would be little interaction between the vibration and the moving fluid, resulting in a much weaker or undetectable Coriolis signal. So the correct angle is a right angle to the flow.