Patent ID: 10788348

Abstract:
A method and apparatus for a flowmeter (5) is provided. The method comprises the steps of placing a material in a flow tube (130, 130′) while exciting a vibration mode of the flow tube (130, 130′). Exciting the vibration mode of the flow tube (130, 130′) comprises the steps of periodically driving a first driver (180L) with a first signal and periodically driving a second driver (180R) with a second signal, wherein the second driver (180R) is driven essentially in phase with the first driver (180L), but wherein the first driver's (180L) drive amplitude modulated signal reaches a maximum amplitude when the second driver's (180R) drive modulated signal reaches a minimal amplitude, and the first driver's (180L) drive amplitude modulated signal reaches a minimum amplitude when the second driver's (180R) drive amplitude modulated signal reaches a maximum amplitude. The method also comprises the steps of measuring the relative phase between a first pickoff (170L) and a second pickoff (170R) and determining a relative phase of a right eigenvector for the flow tube (130, 130′).