Process device with density measurement
AssigneeRosemount Inc.
InventorMark S. Schumacher
Life of this patent
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Abstract
A process variable transmitter for measuring a process variable of a process fluid in a vessel includes first and second pressure couplings arranged to receive a first pressure and a second pressure of process fluid in the vessel. These pressures are related to the density of the process fluid. A sensor provides a sensor output related to the process fluid in the vessel. Measurement circuitry is configured to calculate a calculated process variable of the process fluid in the vessel based upon the first and second pressures and the sensed process variable.
Claims24
A process variable transmitter for measuring a process variable of a process fluid in a vessel, comprising;
- first and second pressure couplings arranged to receive a first pressure and a second pressure of process fluid in the vessel wherein a difference between the first pressure and the second pressure is related to weight of the process fluid;
- a sensor having a sensed process variable output related to the process fluid in the vessel;
- and
- measurement circuitry configured to calculate a calculated process variable of the process fluid in the vessel based upon density of the process fluid determined as a function of weight of the process fluid measured by the first and second pressures and the sensed process variable.
A method for measuring a process variable of a process fluid in a vessel, comprising:
- sensing a process variable of the process fluid in the vessel;
- measuring weight of the process fluid using a differential pressure;
- calculating density of the process of the density based upon the measured weight;
- and
- calculating a calculated process variable of the process fluid based upon the measured process variable and the calculated density.
Dependencies are inferred from the claim text.