Process and device for determining the viscosity of liquids
AssigneeSchott Gerate GmbH
InventorsJochen K. Lehmann, Roland Glatzer, Jutta Hartmann, Dieter Wagner
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Abstract
A process and a device for determining the viscosities of liquids are described, which work quickly, reliably and accurately. The process according to the invention makes use of the fact that disturbing effects are eliminated when measuring the change in the rate of flow of the liquid from the viscometer, while utilizing the change in the hydrostatic pressure during viscosity measurement and that the viscosities can be reliably determined from the measured data by the Hagen-Poiseuille law. The viscometer according to the invention is designed so that the hydrostatic pressure change during measurement is maximal.
Claims17
In a process for determining the viscosity of a Newtonian liquid with a capillary viscometer, comprising a storage vessel and a capillary tube, wherein said liquid flows from said storage vessel through said capillary tube, the improvement wherein:
- the flow rate of liquid through said capillary tube changes with time, and
- the change in the rate of flow of liquid through the viscometer is measured whereby viscosity of the liquid can be determined by the Hagen-Poiseuille law,
A capillary-viscometer comprising a storage vessel and a capillary tube, wherein dimensions of said storage vessel and capillary tube are selected to achieve a maximal change in hydrostatic pressure during viscosity measurement, and wherein said storage vessel exhibits changes in cross-section to permit simultaneous determination of density of a liquid at preset intervals.
A capillary viscometer for liquids comprising a storage vessel and a capillary tube, wherein dimensions of said storage vessel and capillary tube are selected to achieve a maximal change in hydrostatic pressure during viscosity measurement, and wherein the axis of said storage vessel and/or the axis of said capillary tube are arranged at an angle to the perpendicular.
In a process for determining the viscosity of a Newtonian liquid with a capillary viscometer, comprising a storage vessel and a capillary tube, wherein said liquid flows from said storage vessel through said capillary tube, the improvement wherein:
- the flow rate of liquid through said capillary tube changes with time,
- the change in the rate of flow of liquid through the viscometer is measured whereby viscosity of the liquid can be determined by the Hagen-Poiseuille law, and
- in measuring the change in the rate of flow of liquid, the length of time required for each of a plurality of preset liquid volumes required to pass through preset measuring points is measured.
Dependencies are inferred from the claim text.