Patent ID: 7953564

Claim:
A method comprising: passing a fluid through a flowtube having at least two natural modes of vibration, the modes of vibration having different periods of oscillation; applying a first drive signal to the flowtube such that the flowtube vibrates; receiving a sensor signal from a sensor that is operable to sense a vibration of the flowtube, the sensor signal comprising a first signal component associated with a first one of the modes of vibration, and a second signal component associated with a second one of the modes of vibration; determining one or more parameters of the second mode of vibration by analyzing the received sensor signal over a time period that is defined with respect to the period of oscillation of one of the modes of vibration of the flowtube; generating, based at least in part on the determined parameters of the second mode of vibration, a second drive signal configured to control an amplitude of the second mode of vibration; and applying the second drive signal to the flowtube.