US 5,309,760 AGranted

Method and apparatus for measuring the content of a storage vessel

AssigneeKanto Seiki Co., Ltd.

InventorsKajiro Watanabe, Katushi Ohneda

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Abstract

The peak amplitude values of two different frequency pressure changes produced by the displacement device of a volume sensing arrangement, are obtained and one divided by the other to produce a value indicative of the volume of the unfilled portion of a storage vessel. The contents of the vessel are derived by subtracting the unfilled volume from the vessel capacity. In the embodiments wherein a single pressure sensor is used, the signal is simultaneously filtered with a low pass filter and a band pass filter in order to obtain static and dynamic pressure data. In some embodiments the single sensor is disposed in a chamber in which the displacement means produces two different frequency pressure variations. The chamber is communicated with the storage vessel by a pipe the length and diameter of which are selected to prevent the pressure variations produced by one of the frequencies from being transmitted therethrough. In other embodiments two pressure sensors are used and the special pipe dispensed with and the outputs of the two sensors fed individually to band pass filters.

Claims5

Dependent claims

A measuring arrangement comprising:

a vessel of known volume;
an air bleed, said air bleed providing restricted fluid communicating between the interior of said vessel and the atmosphere;
means defining a chamber;
a displacement device disposed in said chamber, said displacement device being arranged to vary the pressure in said chamber, said displacement device dividing said chamber into first and second portions, the first portion being enclosed within said chamber and said second portion being fluidly communicated with the interior of said vessel;
means providing a limited amount of fluid communication between the first portion of said chamber and the interior of said vessel;
a first pressure sensor, said pressure sensor being responsive to the pressure in the first portion of said chamber and arranged to produce a first output indicative thereof;
a second pressure sensor, said second pressure sensor being responsive to the pressure in said vessel and arranged to produce a second output indicative thereof;
circuit means for receiving the outputs of said first and second pressure sensors and for filtering out first and second data, respectively, said circuit means including means for processing the first and second data in a manner which produces a signal indicative of the contents of said vessel.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/743,515Filed 12 Aug 1991 · continuation in part
Priority: JP 63-1696337 Jul 1988
Granted: 10 May 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G01F 23/18
By measurement of pressure: indicating, recording or alarm devices actuated electrically
G01F 23/14
Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm: by…
G01F
Measuring volume, volume flow, mass flow or liquid level