Capacitance probe for fluid flow and volume measurements
First Claim
1. An electromagnetic flow monitor for monitoring flow of a material within a flow stream, comprising:
- first probe, said first probe having first and second elongate electrodes substantially parallel with respect to each other, said first and second elongate electrodes having a spacing therebetween that is functionally related to said fluid to be monitored, said first and second elongate electrodes defining a flow aperture;
a signal generator operative to produce a reference signal for said probe;
a cable for applying said reference signal to said probe and for receiving a reflected signal therefrom;
flow rate means for providing said flow stream at a known flow rate through said flow aperture;
a flow director for directing said flow stream between said first and second elongate electrodes; and
detection circuits responsive to a permittivity of said material within said flow stream between said first and second elongate electrodes.
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Accused Products
Abstract
Method and apparatus for making measurements on fluids are disclosed, including the use of a capacitive probe for measuring the flow volume of a material within a flow stream. The capacitance probe has at least two elongate electrodes and, in a specific embodiment of the invention, has three parallel elongate electrodes with the center electrode being an extension of the center conductor of a co-axial cable. A conductance probe is also provided to provide more accurate flow volume data in response to conductivity of the material within the flow stream. A preferred embodiment of the present invention provides for a gas flow stream through a micro-gravity environment that allows for monitoring a flow volume of a fluid sample, such as a urine sample, that is entrained within the gas flow stream.
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Citations
13 Claims
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1. An electromagnetic flow monitor for monitoring flow of a material within a flow stream, comprising:
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first probe, said first probe having first and second elongate electrodes substantially parallel with respect to each other, said first and second elongate electrodes having a spacing therebetween that is functionally related to said fluid to be monitored, said first and second elongate electrodes defining a flow aperture; a signal generator operative to produce a reference signal for said probe; a cable for applying said reference signal to said probe and for receiving a reflected signal therefrom; flow rate means for providing said flow stream at a known flow rate through said flow aperture; a flow director for directing said flow stream between said first and second elongate electrodes; and detection circuits responsive to a permittivity of said material within said flow stream between said first and second elongate electrodes. - View Dependent Claims (2, 3, 4)
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5. An electromagnetic flow monitor for monitoring flow of a material within a flow stream, comprising:
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a first probe, said first probe having at least two electrodes, said at least two electrodes having a substantially constant spacing there between; a second probe, said second probe having first and second electrodes; a cable for receiving a reflected signal from said first probe; detection circuitry responsive to said reflected signal from said first probe indicative of a permittivity of said flow stream between said first and second electrodes for producing an analog permittivity signal, said detection circuitry being responsive to a conductivity of said material for producing an analog conductivity signal; analog to digital conversion circuitry for converting said analog permittivity signal and said analog conductivity signal, respectively, to a digital permittivity signal and a digital conductivity signal; and calculating circuitry for combining said digital permittivity signal and said digital conductivity signal to provide an output related to flow of said material within said flow stream. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. A method for monitoring flow of a material within a flow stream, comprising the steps of:
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forming an aperture by providing at least two electrodes to be substantially parallel with respect to each other; directing all flow of said flow stream through said aperture; determining a rate of flow of said flow stream containing said material through said aperture; providing a spacing between said two elongate electrodes functionally related to the size of droplet of said material to be monitored within said flow stream; applying a radio reference signal to said at least two electrodes; obtaining a reflected signal from said at least two electrodes that is indicative of a permittivity of said flow stream between said first and second electrodes; providing a second probe, said second probe being responsive to a conductivity of said material; and obtaining a flow rate of said material through said aperture corrected for said conductivity of said material. - View Dependent Claims (13)
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Specification