System to determine the level and weight of liquid in a tank or the like
First Claim
1. A system for measuring the density of liquid in a container, comprising(a) a first liquid pressure sensor mounted in a container of liquid and located at a predetermined distance above the bottom of said container, said pressure sensor has a rigid sensor body with a membrane resting surface thereon, a gas inlet communicating to an inlet segment of said resting surface and a gas outlet communicating from an outlet segment on said resting surface, a flexible membrane member is positioned on said resting surface and lies in flush contact therewith in an undistorted state in the absence of gas flow between said inlet and said outlet, and means securing and sealing said flexible membrane to said resting surface to make said membrane responsive to gas flow from said inlet to said outlet in passing between said resting surface and said membrane as influenced by hydraulic liquid pressure acting on the side of said membrane opposite said resting surface,(b) a second liquid pressure sensor similar to said first pressure sensor and also mounted in said container at a known elevation above that of said first pressure sensor,(c) a constant flow rate gas source connected by a first conduit means to the inlet of said first pressure sensor,(d) a second conduit means communicably connecting the outlet of said first pressure sensor to the inlet of said second pressure sensor,(e) a third conduit means communicably connecting the outlet of said second pressure sensor to the atmosphere at substantially atmospheric pressure,(f) a gas pressure measuring means operably connected to measure the gas pressure at the inlet of said first pressure sensor,(g) a differential gas pressure measuring means operably connected to measure the differential gas pressure between the inlet of said first pressure sensor and the inlet of said second pressure sensor, and(h) a density calculator means operably connected to said gas pressure measuring means and said differential gas pressure measuring means to determine the depth and density of liquid in the container.
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0 Petitions
Accused Products
Abstract
A system for measuring the density of a hydrostatic liquid in a container includes a pair of serially connected pressure sensors mounted in the liquid, a constant volume gas flow source connected to an inlet of one pressure sensor, a second pressure sensor connected to the outlet of the first pressure sensor, and a vent is connected between the second pressure sensor outlet and the atmosphere. A gauge or pressure transducer in the gas conduit from the source to the first pressure sensor provides pressure measurements that can be used to determine the level of liquid in the container and a differential pressure transducer across the first pressure sensor can be used to determine density of the liquid. Exhaust gas from the pressure sensors is passed to the atmosphere through a pressure buffering device in one construction of the system. The pressure sensors each have a rigid body with a generally circular resting surface over which a flexible diaphragm member is positioned. A gas inlet communicates to the peripheral portion of the resting surface through the annular groove. A gas outlet is provided at a central portion of the resting surface for communication with an outlet conduit.
42 Citations
13 Claims
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1. A system for measuring the density of liquid in a container, comprising
(a) a first liquid pressure sensor mounted in a container of liquid and located at a predetermined distance above the bottom of said container, said pressure sensor has a rigid sensor body with a membrane resting surface thereon, a gas inlet communicating to an inlet segment of said resting surface and a gas outlet communicating from an outlet segment on said resting surface, a flexible membrane member is positioned on said resting surface and lies in flush contact therewith in an undistorted state in the absence of gas flow between said inlet and said outlet, and means securing and sealing said flexible membrane to said resting surface to make said membrane responsive to gas flow from said inlet to said outlet in passing between said resting surface and said membrane as influenced by hydraulic liquid pressure acting on the side of said membrane opposite said resting surface, (b) a second liquid pressure sensor similar to said first pressure sensor and also mounted in said container at a known elevation above that of said first pressure sensor, (c) a constant flow rate gas source connected by a first conduit means to the inlet of said first pressure sensor, (d) a second conduit means communicably connecting the outlet of said first pressure sensor to the inlet of said second pressure sensor, (e) a third conduit means communicably connecting the outlet of said second pressure sensor to the atmosphere at substantially atmospheric pressure, (f) a gas pressure measuring means operably connected to measure the gas pressure at the inlet of said first pressure sensor, (g) a differential gas pressure measuring means operably connected to measure the differential gas pressure between the inlet of said first pressure sensor and the inlet of said second pressure sensor, and (h) a density calculator means operably connected to said gas pressure measuring means and said differential gas pressure measuring means to determine the depth and density of liquid in the container.
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7. A system for measuring the density of liquid in a container that is open to the atmosphere, comprising
(a) a first liquid pressure sensor mounted in a container of liquid that is open to the atmosphere and located at a predetermined distance above the bottom of said container, said pressure sensor has a rigid sensor body with a membrane resting surface thereon, a gas inlet communicating to an inlet segment of said resting surface and a gas outlet communicating from an outlet segment on said surface, a flexible membrane member is positioned on said resting surface and positioned in flush contact therewith in an undistorted state in the absence of gas flow between said inlet and said outlet, and means securing and sealing said flexible membrane over and around the periphery of said resting surface to make said membrane responsive to gas flow from said inlet to said outlet in passing between said resting surface and said membrane as influenced by hydraulic liquid pressure acting on the side of said membrane opposite said resting surface, (b) a second liquid pressure sensor similar to said first pressure sensor and also mounted in said container at a known elevation above that of said first liquid pressure sensor, (c) a constant flow rate gas source with an output connected to the inlet of said first pressure sensor, (d) said second liquid pressure sensor having its inlet communicably connected to the outlet of said first pressure sensor, (e) an outlet gas pressure buffering device mounted in said container at an elevation above said second liquid pressure sensor having its inlet communicably connected to the outlet of said second pressure sensor, and having its outlet communicably connected to an atmospheric pressure vent, (f) a differential gas pressure measuring means operably connected to measure the differential pressure between the inlet of said first pressure sensor and the inlet of said second pressure sensor, and (g) a density calculator means operably connected to said differential pressure measuring means to determine the density of liquid in the container.
Specification