Mass flow meter

A mass flow meter, comprising:

• a tubular housing extending along a longitudinal axis and configured to receive a flow of fluid therethrough;
• a flexible plate extending along at least a part of the tubular housing and at least partially coupled to an interior wall of the tubular housing at opposed longitudinal ends of the flexible plate such that the flexible plate is able to vibrate in torsion, wherein a sum of the at least two oscillating torques are less than the largest of the at least two oscillating torques;
• at least one electromagnetic actuator system configured to apply at least two oscillating torques to the flexible plate sufficient to vibrate the flexible plate in torsion;
• and
• at least two sensor systems configured to measure oscillations of the flexible plate as a function of time at locations arising from the at least two applied oscillating torques.

A method for measuring mass flow through at least one tubular housing, the method comprising:

• receiving a flow of fluid through the at least one tubular housing, wherein the tubular housing comprises a flexible plate extending along at least a part of the at least one tubular housing and is at least partially coupled to an interior wall of the at least one tubular housing at opposed longitudinal ends of the flexible plate such that the flexible plate is able to vibrate in torsion;
• driving by at least one actuator system the flexible plate within the at least one tubular housing to vibrate in a torsional mode at a selected frequency by applying at least two oscillating torques to the flexible plate to vibrate the flexible plate in torsion, wherein a sum of the at least two oscillating torques are less than the largest of the at least two oscillating torques;
• measuring a plurality of oscillations of the flexible plate by at least two sensor systems configured to measure oscillations of the flexible plate as a function of time at at least two locations arising from the at least two applied oscillating torques;
• and
• determining a mass flow of the fluid flowing within the at least one tubular housing based on a phase shift between the oscillations measured at the at least two locations.