Coriolis flow meter with adjustable excitation phase
AssigneeABB Kent-Taylor Limited
InventorTroy Wray
Life of this patent
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Abstract
In a coriolis flow meter, two drivers are provided and a measure of mass flow rate derived from the adjustment of the input signals to each driver required to achieve a desired phase shift in the output. This may give higher accuracy compared to conventional meters in which the phase shift is simply measured, and may also enable determination of other characteristics of the fluid.
Claims18
Apparatus for obtaining a measure of mass flow rate in a fluid conduit comprising:
- excitation means for applying vibration to a portion of the conduit;
- sensor means for detecting a measure of phase difference in the vibration at first and second mutually spaced apart points in the flow conduit;
- and wherein
- the excitation applied by said excitation means is adjustable to compensate for variation in said phase difference caused by flow of fluid through the conduit and wherein adjustment of said excitation is selected to alter said phase difference.
A method of obtaining a measure of mass flow rate in a fluid conduit comprising applying vibration to a portion of the conduit;
- detecting a measure of phase difference in the vibration at first and second mutually spaced apart points in the flow conduit;
- adjusting the excitation applied to the conduit to compensate for variation in said phase difference caused by flow of fluid through the conduit;
- and
- obtaining a measure of the mass flow rate based on at least a measure of the amount of adjustment and wherein adjustment of said excitation is selected to alter said phase difference.
A method of verifying the accuracy of a mass flow meter which includes means for applying vibration to a portion of a conduit and means for detecting a phase difference in vibration at first and second mutually spaced apart locations in the conduit, the method comprising adjusting the excitation applied to the conduit and comparing a measured value of said phase difference with a predicted value of phase difference and wherein adjustment of said excitation is selected to alter said phase difference.
Dependencies are inferred from the claim text.