RU2319134C2 - Device for determining viscosity - Google Patents

Abstract

FIELD: investigating or analyzing of materials.

SUBSTANCE: device comprises hollow housing, capillary coaxially mounted inside the housing, and adjustable clamp mounted at the exit of the hollow housing. The hollow housing and capillary are mounted vertically in the bottom section of the housing. The bath has two pressure-tight vessels for taking reference liquid and liquid to be investigated. .

EFFECT: simplified design.

3 dwg

Description

The invention relates to techniques, namely, devices for determining the rheological characteristics of biological fluids (water, blood, etc.), and is a compact pocket viscometer for rapid analysis of the studied viscous medium.

A known viscometer made in the form of a fountain pen, containing a hollow cylindrical body, which is filled with the test fluid with a ball floating in it. The viscometer is closed at both ends by removable covers, and the case is locked with a writing device isolated from liquid and equipped with a removable cap containing a recording device, which is made in the form of an electronic stopwatch [patent RU No. 2265204, C2, 2003]. The viscosity in this viscometer is determined by Stokes law.

A disadvantage of the known device is the small diameter of the working area, and therefore the walls of this area have a significant effect on the movement of the ball inside the liquid.

The closest to the achieved result is a medical viscometer VK-4 [Remizov A.N. Medical and biological physics. Textbook for honey. Universities - M .: Higher School, 1987 - 638 p., p.176] (which does not use the Stokes law), containing two graduated capillaries connected by rubber tubes, a tee with a tap, from which the tube comes with a tip. A reference fluid is drawn into one of the capillaries to a certain level, closing the tap, the test fluid is drawn into the second capillary to the same level, then, opening the tap, the fluids are continued to move along the capillaries, and the viscosity of the test fluid relative to the reference is measured by the difference in fluid levels in the capillaries.

The disadvantages of the known device are:

- low compactness of the device;

- the complexity and duration of measurements, which is not permissible for the express analysis of rapidly changing biological fluids;

- the impossibility of obtaining with its help a surface tension coefficient.

The technical result of the claimed device is to simplify the design of the viscometer, increasing ease of use and expanding the scope of its application in field conditions.

The technical result is achieved by the fact that the capillary is coaxially fixed inside the hollow body, and an adjustable clamp is installed at the outlet of the hollow body, and the hollow body and capillary are rigidly mounted vertically in the gravity field at the bottom to the bathtub, which consists of two sealed containers for sampling the reference and test fluids.

The drawings show a diagram of the device of the viscometer, where in Fig.1, 2 shows two projections of the device, and in Fig.3 - on an enlarged scale, the hole in the housing 1.

The viscometer for biological fluids consists of a housing 1 made of a transparent material, for example, a glass tube, and having marks, inside the housing 1 there is a cylindrical capillary 2, forming a coaxial gap 3. With it, the housing 1 and the capillary 2 are rigidly attached to the bath 4, consisting of two sealed containers: internal 5 and external 6. The housing 1 is provided with an opening 7 through which the test liquid enters from the internal tank 5 of the bath 4 into the coaxial gap 3. The external tank 6 of the bath 4 with the help of fixing rods 8 g JCOMM is fixed to the inner receptacle 5 and communicates with the capillary 2 for sampling a reference fluid. In the upper part at the outlet of the hollow body 1, an adjustable clamp 9 is installed.

A viscometer for biological fluids works as follows.

To calibrate the viscometer for biological fluids, the same liquid, for example, distilled water, is poured into both tanks 5 and 6 of bath 4 when the clamp 9 is completely closed, then it is opened and the maximum rise of the reference fluid in the capillary 2 and coaxial gap 3 is fixed. The design features of the viscometer are selected so that the maximum lifting height in the capillary 2 and the coaxial gap 3 is approximately the same. So, for a glass capillary 2 and distilled water as a reference liquid, the coaxial gap 3 is 0.4 mm with an inner diameter of capillary 2 of 0.6 mm, the maximum height is the same and is 22 mm. At a height equal to half the height of the maximum rise on the capillary 2, a mark is made and the relative viscosity is judged by the achievement of this mark by the reference fluid and the level of achievement of the test fluid, which is recorded on a transparent case that has marks every 0.5 mm.

After calibration, the test liquid is poured into the container 5, which communicates with the coaxial gap 3, and the reference liquid in the tank 6, which communicates with the capillary 2. A fluid with a presumably higher viscosity than the reference is always drawn into the external coaxial gap 3 in order to prevent obscuration of the internal capillary 2 with the reference liquid by the test liquid. The relative viscosity is judged by the ratio of the elevation heights of the test and reference fluids when the reference fluid reaches a mark set at a height equal to half the height of the maximum lift due to surface tension forces. At this moment, the clamp 9 is closed, and the movement of the liquid is stopped, which allows an accurate reading of the positions of the menisci. Subsequently, the clamp is opened, and the relative surface tension coefficient of both fluids is judged by the maximum lifting height.

The achieved result in the proposed viscometer for biological fluids, the positive effect is as follows:

1) simplification of the design and operation of the viscometer, as well as reducing the complexity of the tests reduces the time spent on the experiment, which makes it possible to conduct a quick express analysis of the viscosity of various biological fluids;

2) the additional ability to determine the surface tension coefficient of liquids is added;

3) the scope of application by individual consumers for a portable portable viscometer for biological fluids in the field is expanding.

Claims (1)

A device for determining the relative viscosity of biological fluids, containing an adjustable clamp at the outlet of the hollow body, a transparent capillary fixed coaxially inside the hollow body, forming a coaxial gap so that the maximum height of the rise of the reference fluid in the capillary and the coaxial gap is the same, the hollow body and the capillary are rigidly attached to the bottom of the bath, consisting of internal and external sealed containers for sampling the reference and test fluids, while the test fluid, n poured into the internal container, communicates with a coaxial gap through the opening of the hollow body, the reference liquid poured into the external cavity communicates with the capillary, and a mark is made at a height equal to half the height of the maximum rise of the reference liquid in the capillary.

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