Measuring and testing – Liquid analysis or analysis of the suspension of solids in a... – Viscosity
Patent
1985-01-30
1986-07-29
Levy, Stewart J.
Measuring and testing
Liquid analysis or analysis of the suspension of solids in a...
Viscosity
G01N 1110
Patent
active
046025014
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Related Technical Field
The invention relates to a viscometer, an elastometer, a viscoelastometer or a rheometer. Hereafter they all are called rheometer as a general term. In a movable-piece type of rheometer, a part of the movable-piece or the whole of the piece is immersed in or contacting with or fixed to a viscoelastic sample to be measured, and it makes relative motion as a sensing member to the sample. Force on the movable-piece is influenced by the rheological properties of the sample. The rheological properties of the sample are determined usually according to the relation between the force on the sensing member and the relative motion of the sensing member to the measured sample.
2. Background Art
The drive or support mechanism in the prior art systems involves elastic supporting elements, for example, torsion bars or plate springs, or bearing elements, for example, rotary bearings or linear sliding bearings.
In some types of conventional movable-piece rheometer a movable-piece is plunged into the gel-like high viscoelastic sample.
But such a mechanical support structure as an elastic support structure or a bearing has complicated structure and is easily damaged. It is inconvenient to change samples. Moreover they have difficulty in measuring a small amount of sample because it is impossible to manufacture a very small dimension of movable-piece and it is difficult to measure at high test frequencies. The movable-piece which is plunged into a sample is difficult in holding itself in the intended sensing position because of its gradual dislocation during measurement.
DISCLOSURE OF THE INVENTION
The present invention solves these serious problems in the conventional rheometers as mentioned above, and provides a rheometer and a convenient method to determine precisely the rheological properties of a sample with a very small amount of the sample covering high test frequency with simple mechanical structure.
That is, a rheometer of the present invention is characterized in that, when it determines viscosity, elasticity or rheological properties of a sample material from the relative motion of a sensing member to the sample, a magnetic movable-piece as a sensing member immersed in, contacting with or fixed to a sample material by a magnetic drive or support means for controlling the relative position or motion of said movable-piece to the sample material by magnetic force through a servomechanism following predetermined position or motion in a non-contact manner instead of any mechanical drive or support structure.
The present invention has merits and advantages mentioned below.
(a) A rheometer of the present invention has no mechanical support structure. Therefore, a very small sensing-member can be manufactured. It does not require troublesome adjustment of the support structure. No deformation or destruction of the support structure is encountered in changing samples. It provides long mechanical life without any trouble around support structure. A movable-piece and a sample can be sealed hermetically in a disposable container cartridge. So that, the same container for storage can be used also for measurement, and it provides quick convenient change of samples without contamination of samples, repetition of measurement of the same sample, and it avoids denaturalization due to evaporation, scattering of, for example, radioactive samples. Temperature control, for example, warming or cooling of a sample material is managed easily.
(b) A very small sensing-member can be employed. Therefore, the rheometer can measure accurately a very small amount of sample. The sensing-member accurately works even at high test frequency, and it is hardly interrupted by mass effect of a movable-piece.
(c) The movable-piece does not touch a container wall, and is not influenced by support structure. Therefore, the rheometer accurately measures even low viscoelastic samples and even in test condition of very small viscoelastic force. Calibration of the magnetic force against the coil current is easily per
REFERENCES:
patent: 2957338 (1960-10-01), Kennedy et al.
patent: 3967934 (1976-07-01), Seitz et al.
Low-Shear 30 catalog, Contraves, Switzerland.
Rotovisco RV 100, CV 100 catalog, Haake, West Germany.
Oscillating Plate Viscometer by Oka, S, 1960, Academic Press, NY, pp. 65-67.
Parallel Plate Plastomer by Oka, S, 1960, Academic Press, NY, pp. 73-75.
Rheology of Biological Systems, Lutz, R. J. et al., 1973, pp. 130-139.
Rheological Properties of Microliter Quantities of Normal Mucus, King, M. et al., pp. 797-802.
A Modified Oscillating Sphere Magnetic Microrheometer For Use With Biological Secretions, James, S. L. et al, 1982, pp. 179-180.
Levy Stewart J.
Roskos Joseph W.
LandOfFree
Rheometer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rheometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rheometer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-695227