Measuring and testing – Liquid level or depth gauge – Hydrostatic pressure type
Patent
1994-11-29
1997-06-10
Chilcot, Richard
Measuring and testing
Liquid level or depth gauge
Hydrostatic pressure type
73749, G01L 900
Patent
active
056365470
ABSTRACT:
A liquid level monitoring system, which monitors the level of liquid in a storage tank, includes a differential pressure sensor that uses a magnetic fluid, or ferrofluid, sensing element. The pressure sensor is U-shaped with a first one leg connected, via a first pressure chamber, to a bubbler tube that extends downwardly into the storage tank. The second leg of the U-shaped sensor connects to a second pressure chamber, which applies to the second leg a selected, fixed pressure. The pressure applied to the first leg of the sensor is proportional to the hydrostatic back pressure in the bubbler tube, which varies directly with the level of liquid in the storage tank. Wound around the legs of the pressure sensor are inductance coils. The inductances of these coils change as the ferrofluid sensing element moves within the sensor. Accordingly, the inductances change as the level of liquid in the storage tank varies. The inductor coils are connected to a control system which produces a control signal based on the differences of the inductances. This control signal thus varies essentially continuously with changes in the level of liquid in the storage tank. The control signal is preferably used to control a storage tank control system which includes various pumps. In response to the control signal, the pumps force liquid into or out of the storage tank, as appropriate. Alternatively, an array of sensing elements may be used to determine the position of the ferrofluid. Signals from the various sensing elements in the array are essentially encoded to produce an output signal that corresponds to the level of fluid in the storage tank.
REFERENCES:
patent: 2758476 (1956-08-01), Donald et al.
patent: 3103821 (1963-09-01), Wright
patent: 3215190 (1965-11-01), Svanoe
patent: 3398394 (1968-08-01), Luehrmann et al.
patent: 3573784 (1971-04-01), Backofer et al.
patent: 3665209 (1972-05-01), Webb et al.
patent: 3751185 (1973-08-01), Gottliebson et al.
patent: 3803917 (1974-04-01), Reese et al.
patent: 3947692 (1976-03-01), Payne
patent: 4265110 (1981-05-01), Moulin
patent: 4380933 (1983-04-01), Irvin
patent: 4462259 (1984-07-01), Stoltman et al.
patent: 4739663 (1988-04-01), Peterson et al.
patent: 4782704 (1988-11-01), Webb
patent: 5249000 (1993-09-01), Raj et al.
Lathi, B.P.; Modern Digital and Analog Communication Systems (New York, Holt, Rinehart and Winston); pp. 214-216. (1983).
Greyson Jay
Ionescu Christian
Raj Kuldip
Amrorwicz Paul D.
Chilcot Richard
Ferrofluidics Corporation
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