RU2612049C1 - Viscometer - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: viscometer consists of a glass-type viscometer VPZh-4 with diagonally cut off knee and discharge tube, tightly coupled two-way tap, which is tightly connected to a glass syringe. The two-way valve is configured to switch the system to the glass syringe, or to the atmosphere.

EFFECT: reduced time determination of kinematic viscosity with simultaneous simplification of the measurement procedure.

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Description

The invention relates to the field of measurement technology, and in particular to methods of modifying an existing glass capillary viscometer designed to determine the kinematic viscosity of fluids by measuring the expiration time, in seconds, of a certain volume of the test fluid under the influence of gravity at a constant temperature. And it can be used in the chemical and petrochemical industries at any enterprises and factories where the viscosity of the products they produce is the main indicator of quality.

Currently, the following types of viscometers are used: rotational, vibration, capillary, and also falling body viscometers. However, all of the above viscometers, with the exception of capillary, are distinguished by a complicated design.

There is a method of determining the kinematic viscosity of liquid petroleum products by measuring the expiration time of a certain volume of the test fluid under the influence of gravity through a calibrated glass capillary viscometer (GOST 33-2000. Petroleum products. Transparent and opaque liquids. Determination of kinematic viscosity and calculation of dynamic viscosity. Minsk: IPK Pub. standards, 2001, 19 pp.) by the empirical formula of the following relationship:

v = C⋅t,

where v is the kinematic viscosity at 20 ° C, mm ² / s;

C is the calibration constant of the viscometer, mm ² / s ² ;

t is the arithmetic mean of the expiration time, s.

In the above GOST, a VPZh-4 type glass viscometer is described, the work with it (see Fig. 1) is described as follows:

On the outlet tube 3 put on a rubber tube. Then, holding the knee 2 with your finger and turning the viscometer over, lower the knee 1 into the vessel with the oil and suck it (using a rubber bulb, a water-jet pump or otherwise) to the mark M ₂ , making sure that no air bubbles form in the liquid. At the moment when the liquid level reaches the mark M ₂ , the viscometer is removed from the vessel and quickly turned over to its normal position. Remove from the outside of the end of the knee 1 excess fluid and put on it a rubber tube. The viscometer is installed in a thermostat so that the extension 4 is below the liquid level. After holding in the thermostat for at least 15 minutes, the liquid is sucked into the elbow 1 up to about 1/3 of the expansion height 4. The elbow 1 is connected to the atmosphere and the time of the liquid meniscus moving from the mark M ₁ to M _{2 is} determined.

This method is one of the most effective, inexpensive and technically simplified, so it was taken as a basis.

A disadvantage of the VPZh-4 type glass viscometer known from the method is the significant measurement time (40 min) and the rather complicated procedure for filling the viscometer with the test liquid.

The technical result of the invention is the reduction of the time for determining the kinematic viscosity while simplifying the measurement procedure.

The technical result is achieved by the fact that the viscometer consists of a VPZh-4 type glass viscometer with a diagonally cut off elbow and a branch pipe, a two-way valve connected to it, which is connected to a glass syringe, which makes it easy to fill the viscometer with a sample. The whole structure is absolutely tight. In this case, a two-way valve is made with the possibility of switching the system to a glass syringe, with which the viscometer is filled, or to the atmosphere to determine the time of expiration of the test fluid.

The features and essence of the claimed invention are explained in the following detailed description, illustrated by drawings, where the following is shown.

In FIG. 2 presents a viscometer, where:

5 - Viscometer type VPZH-4 with a diagonal cut off elbow and an outlet tube

6 - Two-way valve

7 - Syringe

8 - Test tube

9 - Test tube stand

10 - Tripod

A1 - upper mark

A2 - lower mark

The claimed viscometer works as follows.

The test fluid is placed in test tube 8. Switch the two-way valve 6 to the glass syringe and fill the viscometer with the test liquid from the tube 8. Once the liquid is collected above level A1, switch the two-way valve 6 from the glass syringe to the atmosphere. As soon as the lower meniscus reaches level A1, we note the expiration time, and upon reaching the level A2, we determine the entire expiration time. This procedure is markedly simplified compared to the prototype. Dynamic viscosity is determined according to the standard method described in GOST. Thus, the claimed invention helps to reduce the time of measuring kinematic viscosity by about 30%.

Claims (1)

A viscometer consisting of a VPZh-4 type glass viscometer with a diagonal cut-off elbow and a return tube, a two-way valve sealed to it, which is hermetically connected to a glass syringe, while the two-way valve is made with the possibility of switching the system to a glass syringe or to the atmosphere.

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