Continuous liquid level measurement system
AssigneeCummins Engine Company, Inc.
InventorsAlfred Schuppe, Dean H. Dringenburg, Matthew L. Schneider, Weibo Weng, Mike French
Life of this patent
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Abstract
A continuous liquid level measurement system is disclosed which is based upon a differential pressure measurement. The pressure of the liquid level to be measured is calibrated with a second pressure measurement of the pressure above the liquid in order to get a more accurate pressure measurement which is related in a predetermined manner to the level of the liquid. For instances in which the liquid to be measured is in a harsh environment, the invention provides for a means for mounting the sensitive pressure measurement devices remotely from the liquid.
Claims18
A continuous liquid level measurement system, comprising:
- a shaft having a proximal end and a distal end;
- a differential pressure transducer disposed at the proximal end and having a first pressure input and a second pressure input;
- a flexible bladder disposed at the distal end;
- a first pressure transmission tube disposed within the shaft and coupling the bladder to the first pressure input for substantial equalization of pressure therebetween;
- a reference pressure port formed in the shaft proximal of the bladder;
- and
- a second pressure transmission tube disposed within the shaft and coupling the reference pressure port to the second pressure input for substantial equalization of pressure therebetween;
- wherein when the bladder is placed below the liquid level and the reference pressure port is placed above the liquid level, the differential pressure transducer will measure a pressure of the liquid on the bladder, and thus the liquid level.
A continuous liquid level measurement system, comprising:
- a shaft having a proximal end and a distal end;
- a first pressure transducer disposed at the proximal end and having a first pressure input and a first pressure output signal;
- a second pressure transducer disposed at the proximal end and having a second pressure input and a second pressure output signal;
- a signal processor coupled to the first and second pressure output signals and operative to produce a difference output signal substantially equal to a difference between the first and second pressure output signals;
- a flexible bladder disposed at the distal end;
- a first pressure transmission tube disposed within the shaft and coupling the bladder to the first pressure input for substantial equalization of pressure therebetween;
- a reference pressure port formed in the shaft proximal of the bladder;
- and
- a second pressure transmission tube disposed within the shaft and coupling the reference pressure port to the second pressure input for substantial equalization of pressure therebetween;
- wherein when the bladder is placed below the liquid level and the reference pressure port is placed above the liquid level, the difference output signal will be proportional to a pressure of the liquid on the bladder, and thus the liquid level.
Dependencies are inferred from the claim text.