Density compensator for coriolis-type mass flowmeters
AssigneeThe Foxboro Company
InventorWade M. Mattar
Life of this patent
Estimating the term…
Abstract
A density insensitive mass flowmeter for measuring mass flow of fluid includes a continuous conduit loop with at least two resonant modes of oscillation of conduit and at least one dummy mass disposed on the conduit at a vibrational node of one of said resonant modes of oscillation. The dummy mass has a mass and position on the conduit such that the ratio of resonant frequencies of the resonant modes remains substantially constant for different densities of fluid flowing through the conduit.
Claims26
A density insensitive Coriolis-type mass flowmeter for measuring mass flow of fluid comprising:
- a continuous loop of conduit for transporting said fluid, said loop having first and second resonant modes of oscillation;
- a drive apparatus adapted to drive a section of said conduit;
- a sensing apparatus adapted to measure the oscillatory motion of said conduit;
- and
- at least one dummy mass in addition to and spaced from said drive apparatus and said sensing apparatus, said dummy mass disposed on said conduit, and having a mass and position on said conduit such that the ratio of resonant frequencies of said first and second resonant modes remains substantially constant for different densities of fluid flowing through said conduit.
A density insensitive Coriolis-type mass flowmeter for measuring mass flow of fluid comprising:
- a solid support;
- a loop of conduit having an inlet and an outlet connected to said support and having a substantially straight section;
- a pair of drivers disposed at the ends of the straight section of said conduit, said drivers oscillating said straight section in a first resonant mode;
- a sensor adapted to measure the motion of said straight section;
- and
- at least one dummy mass in addition to and spaced from said pair of drivers and said sensor, said dummy mass disposed on said conduit, and having a mass and position on said conduit such that the ratio of resonant frequencies of said first resonant mode and a second resonant mode remains substantially constant for different densities of fluid flowing through said conduit.
Dependencies are inferred from the claim text.