JP2007108045A - Device and method for measuring viscosity of liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring viscosity of liquid optimum to directly measure the viscosity of a mixed liquid of a high-pressure cooling medium like carbon dioxide and a freezer oil, especially a lubricant by a capillary viscometer, and to provide a viscosity measuring method. <P>SOLUTION: The device and method include a container comprising a single crystal sapphire tube for housing the liquid becoming a viscosity measuring target in a hermetic closure and the capillary viscometer arranged in the container in a freely movable manner. In this case, the capillary viscometer contains a magnetic material and is provided with a magnetism producing means for moving the magnetic material from outside of the container in a non-contact state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid viscosity measuring apparatus, and more specifically, a liquid viscosity measuring apparatus and measuring method that are most suitable for directly measuring the viscosity of a mixed liquid of a high-pressure refrigerant such as carbon dioxide and a lubricating oil with a capillary viscometer. It is about.

The physical property of a liquid has a viscosity that represents its viscosity. Viscosity is one of the most important physical properties for lubricating oils and is an important factor in the lubrication of machine elements. Here, as a device for measuring the viscosity of a liquid, various types of devices such as a capillary viscometer, a high-pressure falling ball type viscometer, an electromagnetic vibration type viscometer, and the like have been known. A type of viscometer is used. A capillary viscometer calculates viscosity based on the flow rate of the liquid to be measured flowing through the capillary, and has a predetermined volume of a liquid reservoir that stores the liquid to be measured, and a capillary that circulates the liquid from the liquid reservoir. The viscosity (kinematic viscosity) can be measured with high accuracy.
The high-pressure falling ball viscometer is to obtain a viscosity (absolute viscosity) based on the velocity of a sphere that freely falls at a constant speed and the liquid to be measured and the sphere placed in a high-pressure sealed container. The electromagnetic vibration type viscometer is to immerse an object such as an iron piece in a liquid to be measured and vibrate with an electromagnetic wave to obtain a viscosity (absolute viscosity) based on attenuation of the vibration of the object due to the viscosity of the liquid to be measured. .
Among these, the capillary viscometer can accurately measure the kinematic viscosity by a simple operation in an open space. For this reason, capillary viscometers are widely used for measuring the viscosity of petroleum products. On the other hand, the high-pressure falling ball viscometer and the electromagnetic vibration type viscometer can be used for measuring the absolute viscosity of a liquid in an atmosphere of high-pressure gas because the main body of the viscometer can be formed in a closed container shape. .

The conventional capillary viscometer has a problem that it is not suitable for measuring the viscosity of a liquid in an atmosphere of high-pressure gas because the operation of the viscometer becomes extremely difficult if the main body of the viscometer is placed in a sealed container.
In addition, the high-pressure falling ball viscometer can directly measure the absolute viscosity, but cannot directly measure the kinematic viscosity, and has a problem that the measurement accuracy is not good for a low-viscosity liquid.
In addition, the electromagnetic vibration viscometer can directly measure the absolute viscosity as well as the high-pressure falling ball viscometer, but cannot directly measure the kinematic viscosity, and the temperature changes due to frictional heat caused by vibration of the object. Therefore, there is a problem that the measurement accuracy is not good.
Here, the lubricating oil used in a refrigerator using a refrigerant such as Freon is used in an environment where compressed high-pressure refrigerant gas is an atmosphere. Since the lubricant gas dissolves in the lubricating oil placed in such an atmosphere of high-pressure refrigerant gas, the viscosity of the lubricant changes, and if the amount of refrigerant gas dissolved increases, the performance of the lubricant will be affected. There is. For this reason, in the technical field related to lubricating oil, in particular, lubricating oil for refrigerators, there is a demand for a viscosity measuring device that can directly measure the kinematic viscosity under the pressure and atmosphere in which the lubricating oil is actually used. .

However, since conventional refrigerants have concerns over environmental effects such as ozone depletion and global warming, so-called natural refrigerants such as hydrocarbons, ammonia, and carbon dioxide are attracting attention as refrigerants suitable for environmental protection. Has been.
However, hydrocarbon refrigerants have flammability problems, and ammonia refrigerants have problems such as odor and toxicity. Therefore, they are difficult to use in car air conditioners, etc. Carbon dioxide gas is considered as a next-generation refrigerant, and refrigerant compression type refrigeration equipment using carbon dioxide gas as a refrigerant is being studied.
On the other hand, when carbon dioxide is used as a refrigerant, there is a problem that the operating pressure becomes very high. In a conventional glass container (withstand pressure of 3 MPa), a high-pressure refrigerant like carbon dioxide (7.6 MPa: measurement) (Temperature 31 ° C.)
Further, a liquid viscosity measuring device using a capillary viscometer in a glass closed container has been studied (for example, Patent Document 1), but there is no disclosure regarding the use of a high-pressure refrigerant such as carbon dioxide.

Japanese Patent Laid-Open No. 10-142139

  Under such circumstances, the present invention is a liquid viscosity measuring apparatus and measuring method that are most suitable for directly measuring the viscosity of a mixed liquid of a high-pressure refrigerant such as carbon dioxide gas and a lubricating oil, particularly a refrigerating machine oil, with a capillary viscometer. Is intended to provide.

As a result of intensive studies to develop the preferred viscosity measuring device, the present inventors have found that the object can be achieved by using a single crystal sapphire tube as a container for containing a liquid in a sealed state. It was. The present invention has been completed based on such findings.
That is, the present invention
(1) A liquid viscosity measuring apparatus comprising a container made of a single crystal sapphire tube for containing a liquid whose viscosity is to be measured in a sealed state, and a capillary viscometer movably disposed inside the container. The capillary viscometer is configured to include a magnetic material, and magnetism generating means for moving the magnetic material of the capillary viscometer from the outside of the container in a non-contact manner is provided. Viscosity measuring device,
(2) The liquid viscosity measuring apparatus according to (1), wherein the liquid is a mixed liquid of a refrigerant and a lubricating oil.
(3) The liquid viscosity measuring apparatus according to (2), wherein the refrigerant is carbon dioxide gas,
(4) The container is an elongated sealed pressure-resistant container, the capillary viscometer is movable along the longitudinal direction of the container, and the magnetism generating means is a ring-shaped permanent magnet into which the container can be inserted. The liquid viscosity measuring device of (1) to (3) above,
(5) The liquid viscosity measuring device according to any one of (1) to (4), wherein a proximity sensor for detecting a liquid level position of the liquid inside the capillary viscometer is provided outside the container.
(6) The liquid of the above (1) to (5), wherein the container is formed of a transparent material, and at least a part of the capillary viscometer is formed of a transparent material that allows the inside to be visually recognized. Viscosity measuring device,
(7) In the above (1) to (6), at least one of a pressure sensor, a temperature sensor, a refractive index sensor, a density sensor, and a concentration sensor, whose liquid is the liquid inside the container, is provided in the container. A liquid viscosity measuring device, and (8) a container for containing a liquid whose viscosity is to be measured in a hermetically sealed state, and a capillary viscometer configured to contain a magnetic material is movably disposed inside the container, And the viscosity measurement of the liquid for measuring the viscosity of the liquid using a liquid viscosity measuring device provided with magnetism generating means for moving the magnetic body of the capillary viscometer from the outside of the container in a non-contact manner In the method, by operating the magnetism generating means, the capillary viscometer immersed in the liquid to be measured stored in the container is moved above the liquid, and then the inside of the capillary viscometer Viscosity measurement method of the liquid, characterized in that the liquid level of the liquid to measure the transit time required to pass through the predetermined two positions,
Is to provide.

  According to the present invention, a liquid viscosity measuring apparatus and measurement capable of directly measuring the kinematic viscosity of a mixed liquid of a high-pressure refrigerant such as carbon dioxide and lubricating oil, particularly refrigeration oil, with a simple operation and safely. A method can be provided.

First, in the liquid viscosity measuring apparatus of the present invention, the container for storing the liquid to be measured for viscosity in a sealed state is required to be composed of a single crystal sapphire tube.
The single crystal sapphire used in the present invention has characteristics such as excellent chemical stability, mechanical properties, and transmission wavelength region as compared with conventional quartz glass, and is hard to be damaged because of its high hardness. In particular, the working pressure range is as wide as 0 to 30 MPa with respect to 0 to 3 MPa of the glass tube, and it can be used up to a high pressure region. The preferable working pressure range of the single crystal sapphire tube is 3 to 25 MPa, more preferably 5 to 20 MPa.
The single crystal sapphire tube can be manufactured by a method that is usually used publicly such as the Czochralski (CZ) method or Bernoulli method, but can also be manufactured by the method described in JP-A-54-41281. is there.
The liquid is preferably a mixed liquid of a lubricating oil and a refrigerant, and the refrigerant is preferably carbon dioxide gas that is not toxic or flammable and has no problem in terms of safety and environmental problems.
As described above, by using a single crystal sapphire tube that can be used up to a high pressure region as a container for storing liquid in a sealed state, carbon dioxide gas can be used as a refrigerant, and the kinematic viscosity of the liquid mixture with lubricating oil is directly Measurement can be performed easily and safely.

Furthermore, the liquid viscosity measuring apparatus of the present invention is a liquid viscosity measuring apparatus provided with a capillary viscometer movably disposed inside a container made of a sapphire tube, wherein the capillary viscometer includes a magnetic substance. In addition, it is necessary that a magnetism generating means for moving the magnetic body of the capillary viscometer from the outside of the container in a non-contact manner is provided.
Further, the container is an elongated hermetic pressure-resistant container, the capillary viscometer is movable along the longitudinal direction of the container, and the magnetism generating means includes a ring-shaped permanent magnet into which the container can be inserted. It is preferable that
Moreover, it is desirable that a proximity sensor for detecting a liquid level position of the liquid inside the capillary viscometer is provided outside the container.
Furthermore, it is preferable that the container is formed of a transparent material, and at least a part of the capillary viscometer is formed of a transparent material that allows the inside to be visually recognized.
Furthermore, it is desirable that at least one of a pressure sensor, a temperature sensor, a refractive index sensor, a density sensor, and a concentration sensor, which measure the liquid inside the container, is provided in the container.

  The liquid viscosity measuring method of the present invention is a viscosity measuring method using the liquid viscosity measuring device, and is immersed in the liquid to be measured stored in the container by operating the magnetism generating means. After moving the capillary viscometer above the liquid, it is necessary to measure the passage time required for the liquid level of the liquid inside the capillary viscometer to pass through two predetermined positions.

In the present invention, a predetermined amount of lubricating oil is put inside the container so that the capillary viscometer placed in the pressure resistant container made of the sapphire tube leaves a space that is not immersed in the liquid to be measured. If a capillary viscometer and a predetermined amount of high-pressure refrigerant carbon dioxide are placed in the container, and the container is sealed in this state, a mixed liquid of the lubricant to be measured and the refrigerant is placed under the high-pressure atmosphere gas. It becomes. Here, the capillary viscometer is moved in a non-contact manner by operating the magnetism generating means outside the container by receiving the magnetic force of the magnetism generating means when the magnetic material of the capillary viscometer placed inside the sealed container is received. Can be done.
Therefore, after moving the capillary viscometer to a position where it is completely immersed under the liquid level, after filling the capillary viscometer with the liquid to be measured, the capillary viscometer is completely removed upward from the liquid level. If the above-mentioned liquid is dropped from the capillary viscometer, the liquid level of the liquid in the capillary viscometer is required to pass through two predetermined positions, and the time required to pass between these two positions. By measuring, the kinematic viscosity can be directly measured. Therefore, it becomes possible to directly measure the kinematic viscosity of the mixed liquid in a high-pressure gas atmosphere with a simple operation, thereby achieving the object.

  Then, the container into which the liquid is placed is an elongated hermetic pressure-resistant container, the capillary viscometer is movable along the longitudinal direction of the container, and a ring-shaped permanent magnet is adopted as the magnetism generating means. If the container is inserted inside, the distance between the magnetism generating means and the capillary viscometer is shortened, and the magnetic lines of the magnetism generating means are concentrated in the vicinity of the capillary viscometer. The magnetic force of the magnetic generating means that effectively acts on the body is increased, and the capillary viscometer inside the container can be reliably moved by the magnetic generating means outside the container.

In addition, if a proximity sensor for detecting the liquid level position of the liquid inside the capillary viscometer is provided outside the container, the passage time required for the liquid level of the liquid in the capillary viscometer to pass through two predetermined positions can be reduced. It is possible to perform automatic measurement, which makes it possible to automate the measurement of the kinematic viscosity of the liquid. Further, the container is formed of a transparent material, and at least a part of the capillary viscometer is formed of a transparent material that allows the inside to be visually recognized, and the liquid level in the capillary viscometer is a predetermined distance from a predetermined position. If the decrease can be observed visually, the kinematic viscosity can be directly measured with a simpler structure.
If the container is provided with at least one of a pressure sensor, a temperature sensor, a refractive index sensor, a density sensor and a concentration sensor for measuring the liquid inside the container, the pressure, temperature, refractive index, density and concentration can be measured. The measured value can be obtained simultaneously with the measurement of the kinematic viscosity, and the obtained kinematic viscosity can be corrected quickly.

Next, an embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to these examples.
FIG. 1 shows a viscosity measuring apparatus 1 according to this embodiment. The viscosity measuring apparatus 1 includes a container 10 made of a sapphire tube that stores a liquid 2 to be measured for viscosity in a sealed state, a capillary viscometer 20 disposed inside the container 10, and a constant temperature that stores the container 10. A tank 3 is provided. In addition, although the liquid 2 used as a measuring object is not specified, it is preferable to assume the liquid mixture of lubricating oil and a refrigerant | coolant with many opportunities of kinematic viscosity measurement. The thermostatic chamber 3 is filled with a refrigerant or a heat medium 4 made of a liquid such as water or alcohol.
The thermostat 3 is provided with temperature adjusting means 5 in order to keep the heat medium 4 at a predetermined temperature. Although not shown in the figure, the temperature adjusting means 5 includes a heating device and a cooling device, a temperature sensor for detecting the temperature of the refrigerant or the heat medium 4, and a heating device and a cooling device based on the temperature detected by the temperature sensor. And a controller for controlling the apparatus.

The container 10 is a hermetic pressure resistant container made of a transparent sapphire tube made of glass or the like formed in an elongated tubular shape. While the lower end of the container 10 in the figure is closed, an opening that can be sealed with a lid 11 is provided at the upper end in the figure. As means for introducing a high-pressure refrigerant such as carbon dioxide gas into the container 10 through the lid 11 of the container 10, a pressure-resistant T-shaped joint 24, a needle valve 25, a safety valve 26 and a pressure-resistant hose 27 may be provided. preferable.
The liquid 2 to be measured is put into the container 10 from this opening. Further, an introduction pipe 12 for introducing a refrigerant containing the gas 6 into the container 10 is inserted into the lid 11. A check device 13 such as a check valve is provided at the upper end of the introduction pipe 12 in the drawing so that the gas 6 contained in the container 10 does not leak to the outside. The gas 6 is assumed to be a vapor of a refrigerant that is easily vaporized.
For example, hydrogen, ammonia, propane, chlorofluorocarbon and carbon dioxide gas are used.
Around the container 10, a ring-shaped permanent magnet 14 and two pairs of optical fibers 15 arranged with their end faces facing each other are arranged. The permanent magnet 14 is a magnetism generating means for moving the capillary viscometer 20 from the outside of the container 10 in a non-contact manner.
The container 10 is inserted into the ring-shaped permanent magnet 14. In this state, the permanent magnet 14 can be moved along the side surface of the container 10 between a position near the lower end of the container 10 in the drawing and a predetermined position of the intermediate portion of the container 10. The movement of the permanent magnet 14 is automatically performed by a driving means such as an electric motor via an arm 14A attached to the magnet 14.

In the optical fiber 15, each of the optical fibers 15 </ b> A and 15 </ b> B and the optical fibers 15 </ b> C and 15 </ b> D forms a part of a proximity sensor that detects the liquid level position of the liquid 2 stored in the capillary viscometer 20. ing. That is, the optical fiber 15A projects light from a predetermined light source provided in a viscosity calculator (not shown) toward the end face of the optical fiber 15B. On the other hand, the optical fiber 15B receives light from the optical fiber 15A and guides it to the light receiving element in the viscosity calculator. When the liquid level of the liquid 2 drops to a position between the optical fibers 15A and 15B, the liquid level blocks the light from the optical fiber 15A and the optical fiber 15B cannot receive the light. Thereby, the liquid level position of the liquid 2 in the capillary viscometer 20 is detected at a predetermined position of the container 10.
Similarly, the optical fiber 15C projects light from the above-described light source toward the end face of the optical fiber 15D, while the optical fiber 15D receives light from the optical fiber 15C. . When the liquid level of the liquid 2 is between the optical fibers 15C and 15D and blocks the light from the optical fiber 15C, the optical fiber 15D cannot receive the light, and thereby, at a position different from the optical fibers 15A and 15B, The liquid level position of the liquid 2 in the capillary viscometer 20 is detected. Although not shown in the figure, the container 10 is provided with a pressure sensor, a temperature sensor, a refractive index sensor, a density sensor, and a concentration sensor that measure the liquid 2 inside the container 10. .

The capillary viscometer 20 is open at both ends, and is a transparent cylinder formed of glass or the like. The capillary viscometer 20 is arranged along the longitudinal direction of the container 10 and the longitudinal direction of the container 10. It is possible to move along. In the vicinity of the upper end of the capillary viscometer 20 in the drawing, as shown in FIG. 2, a liquid reservoir 21 having a side wall inflated is provided. Marks 21A and 21B used for measuring the flow rate of the liquid 2 are provided above and below the liquid reservoir 21 in the figure. The marked lines 21A and 21B do not block the light from the optical fibers 15A and 15C.
A capillary portion 22 having a remarkably small inner diameter is provided at a lower portion in the figure of the marked line 21B of the capillary viscometer 20. The kinematic viscosity of the liquid 2 is measured by measuring the time required for a predetermined amount of the liquid 2 to pass through the inside of the narrow tube portion 22 (in other words, the flow rate of the liquid 2). A belt-like outer ring portion 23 made of a magnetic material is fixed to the outer peripheral surface of the side wall of the thin tube portion 22. By moving the permanent magnet 14 along the longitudinal direction of the container 10, the belt-shaped outer ring portion 23 is attracted by magnetic force.
Thus, the capillary viscometer 20 moves following the permanent magnet 14 in a non-contact manner by an operation outside the container 10.

  The moving range of the capillary viscometer 20 is a position A where the liquid viscometer 2 is completely immersed, and positions where the marked lines 21A and 21B are sandwiched between the optical fibers 15A and 15B and the optical fibers 15C and 15D, respectively. It is between B. Here, when the capillary viscometer 20 is moved from position A to position B, the liquid 2 is filled in the capillary viscometer 20. Further, if the capillary viscometer 20 filled with the liquid 2 is held at the position B, the liquid 2 drops from the capillary viscometer 20 and the liquid level of the liquid 2 is lowered until the capillary viscometer 20 becomes empty. I will do it. Then, it is detected by the optical fibers 15C and 15D that the liquid level of the liquid 2 has passed the marked line 21B, a counter (not shown) built in the aforementioned viscosity calculator is activated, and the liquid level of the liquid 2 is The passage of the marked line 21A is detected by the optical fibers 15A and 15B, and the aforementioned counter is stopped. As a result, the above-described viscosity calculator measures the time required for a predetermined amount of the liquid 2 to pass through the inside of the narrow tube portion 22 and automatically measures the kinematic viscosity.

Next, the measurement procedure in this embodiment will be described. First, when a predetermined amount of the lubricating oil liquid 2 and the capillary viscometer 20 are placed in a container 10 made of a sapphire tube having a pressure resistance of 20 MPa, the lid 11 is closed, and then a refrigerant (liquefied carbon dioxide) is introduced. After attaching the safety valve 26 (operating pressure 14 MPa) and the needle valve 25 to the T-shaped joint 24 having a pressure resistance of 30 MPa, the container 10 is immersed in the thermostatic chamber 3 containing the refrigerant 4. Next, the needle valve 25 and the refrigerant sampling line (not shown) are connected via the pressure hose 27. The temperature of the refrigerant 4 is maintained at a temperature equal to or lower than the boiling point (−59 ° C.) of the liquefied carbon dioxide gas used for the sample.
Next, a vacuum pump (not shown) is operated to evacuate the container 10 and the refrigerant collection line to about 13.3 Pa. The vacuum pump is stopped, the original valve of the refrigerant container is opened, and the refrigerant is introduced into the container 10.
By collecting the refrigerant in the container 10 in this manner, the mixing ratio of the lubricating oil and the refrigerant can be set to an arbitrary value.
In the above operation, it is necessary to pay particular attention to the temperature and pressure in the container 10. Here, the operating pressure of the safety valve 26 is preferably about 14 MPa, which is two thirds of the working pressure 20 MPa of the sapphire tube.
When a predetermined amount of refrigerant is introduced, the needle valve 25 is closed, the valve of the refrigerant container is closed, the pressure-resistant hose 27 is disconnected, the internal heating medium 4 is brought to a predetermined temperature by the temperature adjusting means 5 in advance, and the permanent magnet The hermetically sealed container 10 is installed at a predetermined position in the thermostatic chamber 3 in which 14 is lowered to the position A. When the entire container 10 is in a thermal equilibrium state, the driving means for moving the permanent magnet 14 is activated to move the permanent magnet 14 and raise the capillary viscometer 20 to the position B. Thereby, as FIG. 3 shows, the liquid 2 dripped from the capillary viscometer 20 and the liquid level of the liquid 2 falls. Then, the optical fiber 15 detects that the liquid level of the liquid 2 has passed the marked lines 21B and 21A, and the mixed liquid 2 of a predetermined amount of lubricating oil and carbon dioxide refrigerant passes through the inside of the narrow tube portion 22. The time required to do this is automatically measured by the viscosity calculator and the viscosity is automatically measured to complete the measurement.

  The liquid viscosity measuring apparatus of the present invention can directly measure the kinematic viscosity of a mixed liquid of a high-pressure refrigerant such as carbon dioxide and lubricating oil, particularly refrigeration oil, with a simple operation and safely.

It is sectional drawing which shows an example of the embodiment of this invention. It is an expanded sectional view showing an important section of an embodiment showing an example of an embodiment of the present invention. It is sectional drawing which shows one procedure in the measurement of the embodiment of this invention.

Explanation of symbols

1. Viscosity measuring device 10. Container 2. Liquid to be measured 14. 2. Magnetic generation means Thermostatic bath 15. 3. Optical fiber that is part of proximity sensor Refrigerant or heat medium 20. 4. Capillary viscometer Temperature control means 23. Belt-shaped outer ring made of magnetic material

Claims (8)

  A liquid viscosity measuring apparatus comprising a container made of a single crystal sapphire tube for containing a liquid to be measured for viscosity in a sealed state, and a capillary viscometer movably disposed inside the container, A device for measuring the viscosity of a liquid, characterized in that the capillary viscometer includes a magnetic material, and magnetism generating means for moving the magnetic material of the capillary viscometer from the outside of the container in a non-contact manner is provided. .   The liquid viscosity measuring apparatus according to claim 1, wherein the liquid is a mixed liquid of refrigerant and lubricating oil.   The liquid viscosity measuring apparatus according to claim 2, wherein the refrigerant is carbon dioxide.   The container is an elongated hermetic pressure-resistant container, the capillary viscometer is movable along the longitudinal direction of the container, and the magnetism generating means is a ring-shaped permanent magnet through which the container can be inserted. The liquid viscosity measuring apparatus according to claim 1.   The liquid viscosity measuring apparatus according to any one of claims 1 to 4, wherein a proximity sensor for detecting a liquid surface position of the liquid inside the capillary viscometer is provided outside the container.   The viscosity of the liquid according to any one of claims 1 to 5, wherein the container is formed of a transparent material, and at least a part of the capillary viscometer is formed of a transparent material that makes the inside visible. measuring device.   The liquid according to any one of claims 1 to 6, wherein at least one of a pressure sensor, a temperature sensor, a refractive index sensor, a density sensor, and a concentration sensor whose measurement target is the liquid inside the container is provided in the container. Viscosity measuring device. A container for containing a liquid whose viscosity is to be measured in a sealed state, and a capillary viscometer configured to include a magnetic substance is movably disposed in the container, and the magnetic substance of the capillary viscometer is disposed in the container. A liquid viscosity measuring method for measuring the viscosity of the liquid using a liquid viscosity measuring device provided with a magnetism generating means for moving in a non-contact manner from the outside of the container, wherein the magnetism generating means By operating, after moving the capillary viscometer immersed in the liquid to be measured stored in the container above the liquid, the liquid level of the liquid inside the capillary viscometer has two predetermined positions. A method for measuring a viscosity of a liquid, comprising measuring a transit time required for passing.

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