Portable viscometer
First Claim
1. A portable viscometer comprising:
- a viscosity sensor having a rectangular liquid flow channel with an interior space having four sides, wherein the interior space has a fixed depth, a liquid inlet connector coupled to the rectangular liquid flow channel, and at least two separate pressure sensors positioned along the rectangular liquid flow channel that measure a pressure drop of fully developed flow of a liquid flowing through the rectangular liquid flow channel based on an amount of deflection of at least a portion of a side wall of the rectangular liquid flow channel;
a dispensing pump mechanism adapted to couple with a positive displacement pipette that is adapted to contain a liquid, for which a measurement of viscosity is desired, so that operation of the dispensing pump mechanism, in cooperation with the positive displacement pipette, dispenses the liquid from the positive displacement pipette, and the viscosity sensor adapted to couple directly with the positive displacement pipette through the liquid inlet connector so that the liquid for which a measurement of viscosity is desired is forced into the viscosity sensor through the liquid inlet connector when dispensed from the positive displacement pipette; and
a controller that controls operation of the viscometer and processes sensor data, the controller configured to control the viscosity sensor to measure, with the at least two separate pressure sensors, pressures of the liquid flowing through the rectangular liquid flow channel at an initially set flow rate, and automatically determine a flow rate of the liquid, that is distinct from the initially set flow rate, based on the pressures with the at least two separate pressure sensors, so that the liquid is subsequently injected into the rectangular liquid flow channel at the determined flow rate corresponding to subsequent pressures measured by the at least two separate pressure sensors, wherein the at least two separate pressure sensors include a first sensor and a second sensor that is separate from the first sensor, and the controller is further configured to determine whether the pressures measured with the at least two separate pressure sensors are less than threshold pressure for the viscosity measurement, including determining that at least one of the pressure measured with the first pressure sensor and the pressure measured with the second pressure sensor is less than the threshold pressure for the viscosity measurement and increase the flow rate of the liquid so that pressures, measured by the at least two separate pressure sensors, of the liquid flowing through the rectangular liquid flow channel at the increased flow rate are greater than the threshold pressure.
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Accused Products
Abstract
A portable viscometer includes a pump mechanism which cooperates with a positive displacement sample container referred to as a positive displacement pipette, for dispensing, at a known flow rate, a sample of liquid for which viscosity is desired to be determined. The dispensed liquid flows through a flow through miniature viscosity sensor having at least two pressure sensors which measure the pressure drop of the liquid as it flows through a rectangular flow channel, the pressure drop at the known flow rate being proportional to the viscosity. A controller controls operation of the viscometer and processes sensor data, and the resulting measurements of viscosity can be displayed on a display. The positive displacement pipette is removably positioned in the viscometer so that it can be removed from the viscometer when a viscosity test is completed and replaced with another positive displacement pipette containing another liquid to be tested.
77 Citations
28 Claims
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1. A portable viscometer comprising:
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a viscosity sensor having a rectangular liquid flow channel with an interior space having four sides, wherein the interior space has a fixed depth, a liquid inlet connector coupled to the rectangular liquid flow channel, and at least two separate pressure sensors positioned along the rectangular liquid flow channel that measure a pressure drop of fully developed flow of a liquid flowing through the rectangular liquid flow channel based on an amount of deflection of at least a portion of a side wall of the rectangular liquid flow channel; a dispensing pump mechanism adapted to couple with a positive displacement pipette that is adapted to contain a liquid, for which a measurement of viscosity is desired, so that operation of the dispensing pump mechanism, in cooperation with the positive displacement pipette, dispenses the liquid from the positive displacement pipette, and the viscosity sensor adapted to couple directly with the positive displacement pipette through the liquid inlet connector so that the liquid for which a measurement of viscosity is desired is forced into the viscosity sensor through the liquid inlet connector when dispensed from the positive displacement pipette; and a controller that controls operation of the viscometer and processes sensor data, the controller configured to control the viscosity sensor to measure, with the at least two separate pressure sensors, pressures of the liquid flowing through the rectangular liquid flow channel at an initially set flow rate, and automatically determine a flow rate of the liquid, that is distinct from the initially set flow rate, based on the pressures with the at least two separate pressure sensors, so that the liquid is subsequently injected into the rectangular liquid flow channel at the determined flow rate corresponding to subsequent pressures measured by the at least two separate pressure sensors, wherein the at least two separate pressure sensors include a first sensor and a second sensor that is separate from the first sensor, and the controller is further configured to determine whether the pressures measured with the at least two separate pressure sensors are less than threshold pressure for the viscosity measurement, including determining that at least one of the pressure measured with the first pressure sensor and the pressure measured with the second pressure sensor is less than the threshold pressure for the viscosity measurement and increase the flow rate of the liquid so that pressures, measured by the at least two separate pressure sensors, of the liquid flowing through the rectangular liquid flow channel at the increased flow rate are greater than the threshold pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A portable viscometer comprising:
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a dispensing pump mechanism; a viscosity sensor having a rectangular liquid flow channel with an interior space having four sides, wherein the interior space has a fixed depth, a liquid inlet connector coupled to the rectangular liquid flow channel, and at least two separate pressure sensors positioned along the rectangular liquid flow channel that measure a pressure drop of fully developed flow of a liquid flowing through the rectangular liquid flow channel based on an amount of deflection of at least a portion of a side wall of the rectangular liquid flow channel; a mounting mechanism adapted to removably mount a positive displacement pipette adapted to contain a liquid for which a measurement of viscosity is desired, said mounting mechanism adapted to mount the positive displacement pipette in position to cooperate with the dispensing pump mechanism so that the positive displacement pipette couples directly with the viscosity sensor through the liquid inlet connector and operation of the dispensing pump mechanism dispenses the liquid from the positive displacement pipette, and to cooperate with the viscosity sensor so that the liquid for which a measurement of viscosity is desired is forced into the viscosity sensor through the liquid inlet connector when dispensed from the positive displacement pipette; and a controller that controls operation of the viscometer and processes sensor data, the controller configured to control the viscosity sensor to measure, with the at least two separate pressure sensors, pressures of the liquid flowing through the rectangular liquid flow channel at an initially set flow rate, and automatically determine a flow rate of the liquid, that is distinct from the initially set flow rate, based on the pressures with the at least two separate pressure sensors, so that the liquid is subsequently injected into the rectangular liquid flow channel at the determined flow rate corresponding to subsequent pressures measured by the at least two separate pressure sensors, wherein the at least two separate pressure sensors include a first sensor and a second sensor that is separate from the first sensor, and the controller is further configured to determine whether the pressures measured with the at least two separate pressure sensors are less than threshold pressure for the viscosity measurement, including determining that at least one of the pressure measured with the first pressure sensor and the pressure measured with the second pressure sensor is less than the threshold pressure for the viscosity measurement and increase the flow rate of the liquid so that pressures, measured by the at least two separate pressure sensors, of the liquid flowing through the rectangular liquid flow channel at the increased flow rate are greater than the threshold pressure. - View Dependent Claims (24, 25, 26, 27)
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28. A method of obtaining a measurement of viscosity of a liquid for which a measurement of viscosity is desired, comprising the steps of:
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obtaining a portable viscometer comprising; a dispensing pump mechanism; a viscosity sensor having a rectangular liquid flow channel with an interior space having four sides, wherein the interior space has a fixed depth, a liquid inlet connector coupled to the rectangular liquid flow channel, and at least two separate pressure sensors positioned along the rectangular liquid flow channel that measure a pressure drop of fully developed flow of a liquid flowing through the rectangular liquid flow channel based on an amount of deflection of at least a portion of a side wall of the rectangular liquid flow channel; a mounting mechanism adapted to removably mount a positive displacement pipette adapted to contain a sample liquid for which a measurement of viscosity is desired, said mounting mechanism adapted to mount the positive displacement pipette in position to cooperate with the dispensing pump mechanism so that the positive displacement pipette couples directly with the viscosity sensor through the liquid inlet connector and operation of the dispensing pump mechanism dispenses the sample liquid from the positive displacement pipette, and to cooperate with the viscosity sensor so that the sample liquid for which a measurement of viscosity is desired is forced into the viscosity sensor through the liquid inlet connector when dispensed from the positive displacement pipette; and a controller that controls operation of the viscometer and processes sensor data, the controller configured to control the viscosity sensor to measure, with the at least two separate pressure sensors, pressures of the liquid flowing through the rectangular liquid flow channel at an initially set flow rate, and automatically determine a flow rate of the liquid, that is distinct from the initially set flow rate, based on the pressures with the at least two separate pressure sensors, so that the liquid is subsequently injected into the rectangular liquid flow channel at the determined flow rate corresponding to subsequent pressures measured by the at least two separate pressure sensors; obtaining a positive displacement pipette containing a liquid for which a measurement of viscosity is desired; placing the positive displacement pipette containing the liquid for which a measurement of viscosity is desired in the mounting mechanism; and operating the portable viscometer to obtain a measurement of the viscosity of the liquid, for which a measurement of viscosity is desired, contained in the positive displacement pipette while the liquid flows through the portable viscometer, wherein the at least two separate pressure sensors include a first sensor and a second sensor that is separate from the first sensor, and the controller is further configured to determine whether the pressures measured with the at least two separate pressure sensors are less than threshold pressure for the viscosity measurement, including determining that at least one of the pressure measured with the first pressure sensor and the pressure measured with the second pressure sensor is less than the threshold pressure for the viscosity measurement and increase the flow rate of the liquid so that pressures, measured by the at least two separate pressure sensors, of the liquid flowing through the rectangular liquid flow channel at the increased flow rate are greater than the threshold pressure.
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Specification