JP2020134256A - System and method for measuring viscosity of liquid - Google Patents

Abstract

To provide a system and method for measuring the viscosity of a liquid, capable of reducing a measurement time and simply and accurately measuring the viscosity even when the amount of samples to be required is less.SOLUTION: A system for measuring the viscosity of a liquid comprises: a dropping mechanism 1 for dropping a liquid so as to freely fall from a dropping part 11 positioned at a predetermined height as a droplet; a collision part 2 provided to face the dropping part 11 and for colliding the droplet dropped from the dropping part 11; a first measurement device 31 for measuring the state of the droplet when dropped from the dropping part 11; a second measurement device 32 for measuring the state of the droplet just before colliding with the collision part 2; a third measurement device for measuring the state of the droplet after colliding with the collision part 2; and a viscosity calculation device for calculating the viscosity of the liquid on the basis of the measurement results of the first measurement device 31, second measurement device 32 and third measurement device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid viscosity measuring system and a liquid viscosity measuring method, and more particularly to a liquid having a coagulable viscosity such as blood, a paint, or an adhesive, or a liquid having a high melting point such as metal or glass. The present invention relates to a liquid viscosity measuring system capable of easily measuring the viscosity and a liquid viscosity measuring method.

Conventionally, measuring instruments such as a thin tube type, a rotary type, a falling body type, and a vibration type are widely used for measuring the viscosity of a liquid. The thin tube type viscosity measuring instrument is the most classic viscosity measuring instrument, which measures the viscosity based on the volume (flow rate) of the liquid flowing in a unit time and the pressure difference between both ends of the thin tube by passing a liquid sample through the thin tube. is there. The rotary viscosity measuring instrument puts a cylindrical rotor in a liquid sample and obtains the viscosity by utilizing the fact that the rotational torque is proportional to the viscosity of the liquid. The falling body type viscosity measuring instrument is for free-falling a cylindrical or spherical rigid body having a certain size and density in a liquid sample and obtaining the viscosity based on the time for dropping a certain distance. The vibration type viscosity measuring instrument has come to be used in recent years, and obtains the viscosity of a liquid from a driving current for vibrating an oscillator inserted in a liquid sample with a constant amplitude.

However, the conventional viscosity measuring instrument as described above has a complicated structure and is not easy to operate, and the measuring instrument itself is large and expensive. In addition, since such a measuring instrument requires a certain amount of time to measure the viscosity of a liquid, especially when measuring the viscosity of a coagulable liquid such as blood, paint, or adhesive. However, there is a problem that normal viscosity measurement cannot be performed because the liquid solidifies and the viscosity changes during measurement. And, because of the solidified liquid, it is costly to clean the measuring instrument after the measurement, and in some cases, it may lead to the failure of the measuring instrument. In addition, when measuring the viscosity of a liquid of a material having a high melting point such as metal or glass, there is a problem that it is necessary to manufacture an apparatus using a material that can be used in a high temperature environment of about 2000 ° C. Since the physical properties are strongly influenced by the surrounding environment such as temperature and oxygen concentration, there is a problem that it is very difficult to measure the viscosity itself with a conventional measuring instrument. Further, since such a measuring instrument requires a relatively large amount of liquid sample of about several tens of cc to 100 cc, there is a problem that it is not suitable for measuring the viscosity of a liquid for which it is difficult to prepare a sufficient amount of sample. ..

The present invention has been made based on the above circumstances, and the measurement time is shorter than that of a conventional viscosity measuring instrument, and even if the required sample amount is small, the viscosity can be measured easily and accurately. It is an object of the present invention to provide a liquid viscosity measuring system and a liquid viscosity measuring method.

In order to solve the above problems, first, the present invention comprises a dropping means for dropping a liquid as a droplet having a mass M so as to freely drop from a dropping portion located at a predetermined height, and facing the dropping portion. Provided, a collision portion for colliding the droplet dropped from the dropping portion, a first measuring means for measuring the state of the droplet at the time of dropping from the dropping portion, and immediately before the collision with the collision portion. The second measuring means for measuring the state of the droplets, the third measuring means for measuring the state of the droplets after colliding with the collision portion, the measurement results of the first measuring means, and the second measuring means. It is provided with a viscosity calculating means for calculating the viscosity of the liquid based on the measurement result and the measurement result of the third measuring means, and the collision portion has an incident surface, an emitting surface and a reflecting surface, and is incident from the incident surface. It is a total reflection prism that totally reflects the laser beam on the reflection surface and emits it from the emission surface. The liquid that the third measuring means collides with the reflection surface of the total reflection prism and is deformed into a substantially circular shape. Provided is a liquid viscosity measuring system for measuring the maximum spread diameter D _max and the maximum wet spread diameter D _wet of drops (Invention 1).

According to the present invention (Invention 1), the measurement results of the first measuring means, the second measuring means, and the third measuring means show that the liquid is freely dropped as a liquid drop and collides with the collision portion in a short time. The viscosity of the liquid can be measured. As a result, even if the liquid to be measured has coagulability such as blood, paint, and adhesive, and many physical properties such as metal and glass are strongly affected by the surrounding environment such as temperature and oxygen concentration. Even if there is, accurate viscosity measurement is possible. Further, since the viscosity of the liquid can be measured with an extremely small sample amount of one drop, it can be used for measuring the viscosity of a liquid for which it is difficult to prepare a sufficient sample amount, and it is highly versatile.

Further, according to the invention (Invention 1), since the collision portion is a total reflection prism, a portion where the droplet is in contact with the reflection surface of the total reflection prism based on the high-contrast image of the reflected light and the transmitted light. Since the portion that is not in contact with the light is clarified, the maximum wet spread diameter D _wet can be measured with high accuracy by the third measuring means. Therefore, when the droplet collides with the surface of the collision portion and spreads in a substantially circular shape, the peripheral portion of the droplet deformed into a substantially circular shape is the collision portion because the collision speed of the droplet is sufficiently high. It is possible to accurately measure the viscosity of a liquid even when it is separated from the surface or the peripheral portion is split and minute droplets are scattered radially.

In the above invention (Invention 1), it is preferable that the first measuring means suspends the dropping portion and measures the contour shape S of the droplet immediately before it falls freely (Invention 2).

In the above inventions (Inventions 1 and 2), the second measuring means sets the maximum horizontal diameter D ₀ of the droplet and the measuring point at the measuring point immediately before the collision with the reflecting surface of the total reflection prism as the liquid. It is preferable to measure the transit time ΔT required for the droplet to pass (Invention 3).

In the above invention (Invention 1), the first measuring means suspends the dropping portion and measures the contour shape S of the droplet immediately before the free drop, and the second measuring means is the said. It is for measuring the transit time ΔT takes a maximum diameter D ₀ and the measuring point in the horizontal direction of the droplet to the droplet passes through the measurement point immediately before the collision to the reflecting surface of the total reflection prism, the viscosity The calculation means is a first calculation means for calculating the volume V, the density ρ and the surface tension σ of the droplet based on the contour shape S and the mass M measured by the first measurement means, and the second measurement means. It is preferable to provide a second calculation means for calculating the collision speed U _{0 of the} droplet based on the measured maximum diameter D _{0, the} passing time ΔT, and the volume V calculated by the first calculation means (Invention 4). ..

Conventionally, dedicated measuring instruments have been used for measuring the viscosity, density, and surface tension, which are the main physical properties of a liquid. According to the present invention (Invention 4), not only the viscosity of the liquid but also the density and the surface tension can be measured at the same time by one measurement, which is efficient.

In the above invention (Invention 4), the viscosity calculating means has a maximum diameter D ₀ measured by the second measuring means, a maximum wet spread diameter D _wet measured by the third measuring means, and the first calculating means. It is preferable to further provide a third calculation means for calculating the viscosity μ of the liquid using the following correlation equation (1) from the density ρ calculated by the above method and the collision speed U ₀ calculated by the second calculation means (1). Invention 5).

(In equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ, We =, respectively. ρU ₀ ² D ₀ / σ.)

According to the present invention (Invention 5), the viscosity of the liquid to be measured can be determined by using the above formula (1).

In the above invention (Invention 4), the viscosity calculating means has a maximum diameter D ₀ measured by the second measuring means, a maximum spread diameter D _max and a maximum wet spread diameter D _wet measured by the third measuring means. A third calculation means for calculating the viscosity μ of the liquid using the following correlation equation (2) from the density ρ calculated by the first calculation means and the collision speed U ₀ calculated by the second calculation means. Further provision is preferable (Invention 6).

(In equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. Reynolds number Re and Weber number We are Re = ρU ₀ D ₀ / μ, We = ρU ₀ ² D _{0, respectively.} / Σ.)

According to the invention (Invention 6), the viscosity of the liquid to be measured can be determined by using the above formula (2).

In the above invention (Invention 1-6), it is preferable that the liquid is a liquid having coagulability (Invention 7).

In the above invention (Invention 1-6), it is preferable that the liquid is a liquid of a material having a high melting point (Invention 8).

Secondly, the present invention comprises a dropping step of dropping a liquid as a droplet having a mass of M so as to freely drop from a dropping portion located at a predetermined height, and a collision portion provided opposite to the dropping portion. The collision step of colliding the droplets dropped from the dropping portion, the first measurement step of measuring the state of the droplets at the time of dropping from the dropping portion, and the state of the droplets immediately before the collision with the collision portion. The second measurement step to be measured, the third measurement step to measure the state of the droplet after collision with the collision portion, and the measurement results obtained in the first measurement step were obtained in the second measurement step. It includes a measurement result and a viscosity calculation step of calculating the viscosity of the liquid based on the measurement result obtained in the third measurement step, and the collision portion has an incident surface, an exit surface and a reflecting surface, and the incident surface is provided. It is a total reflection prism that totally reflects the laser light incident from the above on the reflection surface and emits it from the emission surface. The third measurement step collides with the reflection surface of the total reflection prism and deforms into a substantially circular shape. Provided is a method for measuring the viscosity of a liquid, which measures the maximum spread diameter D _max and the maximum wet spread diameter D _wet of the droplets (Invention 9).

In the above invention (Invention 9), it is preferable that the first measuring step measures the contour shape S of the droplet immediately before it is suspended from the dropping portion and freely dropped (Invention 10).

In the above inventions (Inventions 9 and 10), the second measurement step sets the maximum horizontal diameter D ₀ of the droplet and the measurement point at the measurement point immediately before the collision with the reflection surface of the total reflection prism with the liquid. It is preferable to measure the transit time ΔT required for the droplet to pass (Invention 11).

In the above invention (Invention 11), the first measuring step is for measuring the contour shape S of the droplet immediately before it is suspended from the dropping portion and freely dropped, and the second measuring step is the said. It is for measuring the transit time ΔT takes a maximum diameter D ₀ and the measuring point in the horizontal direction of the droplet to the droplet passes through the measurement point immediately before the collision to the reflecting surface of the total reflection prism, the viscosity The calculation steps are the first calculation step of calculating the volume V, the density ρ and the surface tension σ of the droplet based on the contour shape S and the mass M measured in the first measurement step, and the second measurement step. It is preferable to include a second calculation step of calculating the collision speed U _{0 of the} droplet based on the measured maximum diameter D _{0, the} passing time ΔT, and the volume V calculated in the first calculation step (Invention 12). ..

In the above invention (Invention 12), the viscosity calculation step is the maximum diameter D ₀ measured in the second measurement step, the maximum wet spread diameter D _wet measured in the third measurement step, and the first calculation step. It is preferable to further include a third calculation step of calculating the viscosity μ of the liquid using the following correlation formula (1) from the density ρ calculated in the above and the collision speed U ₀ calculated in the second calculation step (1). Invention 13).

(In equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ, We =, respectively. ρU ₀ ² D ₀ / σ.)

In the above invention (Invention 12), the viscosity calculation step includes the maximum diameter D ₀ measured in the second measurement step, the maximum spread diameter D _max and the maximum wet spread diameter D _wet measured in the third measurement step. A third calculation step of calculating the viscosity μ of the liquid using the following correlation equation (2) from the density ρ calculated in the first calculation step and the collision speed U ₀ calculated in the second calculation step. Further provision is preferable (Invention 14).

(In equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. Reynolds number Re and Weber number We are Re = ρU ₀ D ₀ / μ, We = ρU ₀ ² D _{0, respectively.} / Σ.)

In the above invention (Invention 9-13), it is preferable that the liquid is a liquid having coagulability (Invention 15).

In the above invention (Invention 9-13), it is preferable that the liquid is a liquid of a material having a high melting point (Invention 16).

According to the liquid viscosity measuring system and the liquid viscosity measuring method of the present invention, the first measuring means, the second measuring means and the first measuring means and the second measuring means and the first measuring means and the second measuring means and the second measuring means in a short time until the liquid is freely dropped as a droplet and collided with the collision portion The viscosity of the liquid can be measured from the measurement results of the three measuring means. As a result, even if the liquid to be measured has coagulability such as blood, paint, and adhesive, and many physical properties such as metal and glass are strongly affected by the surrounding environment such as temperature and oxygen concentration. Even if there is, accurate viscosity measurement is possible. Further, since the viscosity of the liquid can be measured with an extremely small sample amount of one drop, it can be used for measuring the viscosity of a liquid for which it is difficult to prepare a sufficient sample amount, and it is highly versatile.

Then, since the collision portion is a total reflection prism, it is clarified where the droplets are in contact with the reflection surface of the total reflection prism and where they are not in contact, based on the high-contrast image of the reflected light and the transmitted light. Therefore, the maximum wet spread diameter D _wet can be measured with high accuracy by the third measuring means. Therefore, when the droplet collides with the surface of the collision portion and spreads in a substantially circular shape, the peripheral portion of the droplet deformed into a substantially circular shape is the collision portion because the collision speed of the droplet is sufficiently high. It is possible to accurately measure the viscosity of a liquid even when it is separated from the surface or the peripheral portion is split and minute droplets are scattered radially.

It is a schematic diagram which shows the structure of the viscosity measurement system of the liquid which concerns on one Embodiment of this invention. It is a schematic diagram which shows the state which the peripheral part of the droplet deformed into a substantially circular shape is separated from the surface of a collision part when a droplet collides with a collision part and spreads in a substantially circular shape. It is a schematic diagram which shows the state change of the droplet which collided with the collision part, (a) is the state just before the collision, (b) is the state which is being deformed into a substantially circular shape by inertial force after the collision, (c). ) Indicates a state in which the deformation to a substantially circular shape is reached to the maximum, and (d) indicates a state in which after (c), it contracts in the returning direction due to surface tension or the like and reaches equilibrium. It is a schematic diagram which shows the measurement principle of the maximum wet spread diameter _Dwet of a droplet by the TIR method, and (a) shows how the reflected light intensity from a wet region of a droplet spreading on the reflection surface of a total reflection prism is attenuated. (B) shows a schematic diagram showing a wet region image in the direction along the emission surface of the total reflection prism. The measurement result of the third measuring apparatus included in the liquid viscosity measurement system of FIG. 1 is shown, (a) is a droplet image in the direction along the exit surface of the total reflection prism, and (b) is (a). It is a graph which shows the change of the brightness value on a straight line in an image. It is a graph showing the relationship between the maximum diameter (D _max , D _wet ) and the contact angle θ at different collision velocities obtained in the experiment using water, and (a) is the maximum wetting spread diameter D _wet and the contact angle θ. , (B) shows the relationship between the maximum spread diameter D _max and the contact angle θ. In the graph in which the experimental result of the glycerin aqueous solution is added to the experimental result using water shown in FIG. 6 (a), the vertical axis is D _wet / D ₀ and the horizontal axis is Re ^1/5 We ^1/4. Therefore, it is shown that the relationship represented by the correlation equation (1) holds for these liquids having a relatively high surface tension (surface tension: 60-72 mN / m). It is a graph in which the experimental results using isopropanol and silicone oil are plotted with the vertical axis as D _wet / D ₀ and the horizontal axis as Re ^1/5 We ^1/4 , and these liquids having relatively low surface tension (surface). It is shown that the relationship represented by the correlation equation (1) holds for tension: about 20 mN / m). It is a graph which shows that the relationship represented by the correlation equation (2) holds for the liquid which has a wide range of viscosity, surface tension, and contact angle. FIG. 5 is a graph showing the proportionality coefficient of the proportional relationship under various conditions shown in FIG. 9 as a function of the ratio of the thickness h of the droplet to the thickness δ of the viscous boundary layer formed in the collision droplet. It is a figure which shows an example of the method of inferring from the maximum wet spread diameter D _wet using a correlation equation, (a) shows the relationship between the maximum wet spread diameter D _wet and the maximum spread diameter D _max when water is used. The graph represented by (b) shows an experimental correlation equation derived from (a). An image showing the measurement result of the first measuring device included in the liquid viscosity measuring system of FIG. 1, (a) is a photographed image, and (b) is a binarized image of the image of (a). (C) is an image obtained by extracting the contour shape of the droplet immediately before it is suspended from the dropping portion and dropped freely from the image of (b). It is a waveform diagram which shows the measurement result of the 2nd measuring apparatus provided in the liquid viscosity measurement system of FIG. 1, the vertical axis is the horizontal length of the droplet detected by the 2nd measuring apparatus, and the horizontal axis is time. is there. It is a figure which shows the method of obtaining the maximum diameter D ₀ and passage time ΔT of the liquid drop model D ₂ by the 2nd measuring apparatus. Is a graph showing the defective portion of the output value corresponding to the maximum diameter D ₀ (peak) in the measurement result of the second measuring device comprising a viscosity measurement system of the liquid FIG. It is a block diagram which shows the structure of the viscosity calculation apparatus provided in the liquid viscosity measurement system of FIG. It is a flowchart which shows the execution procedure of the viscosity calculation process by the viscosity calculation apparatus of FIG.

Hereinafter, embodiments of the liquid viscosity measurement system and the liquid viscosity measurement method of the present invention will be described with reference to the drawings as appropriate. The embodiments described below are for facilitating the understanding of the present invention and do not limit the present invention in any way.

[Viscosity measurement system]
FIG. 1 is a schematic diagram showing a configuration of a liquid viscosity measurement system according to an embodiment of the present invention. The liquid viscosity measuring system 10 shown in FIG. 1 includes a dropping mechanism 1 having a dropping portion 11, a collision portion 2, a first measuring device 31, a second measuring device 32, a third measuring device 33, and a viscosity calculating device (not shown). Mainly prepared. In the following, for ease of description, appended to the dropping portion 11, D ₁ the droplet D immediately before the free _fall, collide droplets D immediately before collision D _2, the collision portion 2, sometimes the droplets D in a state where deformation has reached a maximum to a substantially circular shape that D _3.

<Maximum spread diameter D _max , maximum wet spread diameter D _wet >
FIG. 3 is a schematic view showing a state change of the droplet D collided with the collision portion 2. FIG. 3A is a state immediately before the collision, and FIG. 3B is deformed into a substantially circular shape by inertial force after the collision. In a certain state, (c) shows a state in which the deformation to a substantially circular shape is reached to the maximum, and (d) shows a state in which after (c), it contracts in the returning direction due to surface tension or the like and reaches equilibrium. In this way, the droplet D that has collided with the collision portion 2 is usually deformed into a substantially circular shape by the inertial force of the collision, and after the deformation reaches the maximum, it contracts in the returning direction due to surface tension or the like and balances. To reach. In the present invention, the maximum spread diameter D _{max of} the droplet D means the maximum diameter of the droplet D deformed into a substantially circular shape in the state shown in FIG. 3C.

In the present invention, the maximum wet spread diameter D _{wet of} the droplet D is the maximum of the region where the droplet D that has reached the maximum spread diameter D _max is in contact with the surface of the collision portion 2, as shown in FIG. Means the diameter. When the droplet D collides with the surface of the collision portion 2 and spreads in a substantially circular shape, in the case of a low collision speed, the difference between the maximum spread diameter D _max and the maximum wet spread diameter D _wet even if the contact angle θ changes. However, in the case of a high collision speed, as the contact angle θ increases, the peripheral edge of the droplet D deformed into a substantially circular shape becomes separated from the surface of the collision portion 2 or the peripheral edge as shown in FIG. Since the portions are split and the minute droplets are scattered radially, the difference between the maximum spread diameter D _max and the maximum wet spread diameter D _wet becomes remarkable. The contact angle θ of the droplet D can be obtained from the image of the droplet D in a state where it contracts in the returning direction due to surface tension or the like after the collision and reaches equilibrium, as shown in FIG. 3D.

FIG. 6 is a graph showing the relationship between the maximum diameter (D _max , D _wet ) and the contact angle θ at different collision velocities obtained in an experiment using water, in which (a) is the maximum wet spread diameter D _wet. The relationship between the contact angle θ and the contact angle θ, and (b) shows the relationship between the maximum spread diameter D _max and the contact angle θ. From FIG. 6, the maximum spread diameter D _max decreases as the contact angle θ increases, and the decrease rate gradually decreases as the collision speed increases, while the maximum wet spread diameter D _wet can be changed even if the collision speed is changed. It can be seen that there is no difference in the rate of decrease. From this, the decrease in the maximum wetting spread diameter D _wet can be expressed only by the contact angle θ without depending on the collision speed.

In FIG. 7, the experimental result of the glycerin aqueous solution is added to the experimental result using water shown in FIG. 6 (a), the vertical axis is set to D _wet / D ₀ , and the horizontal axis is set to Re ^1/5 We ^1/4. In the plotted graph, it is shown that the relationship represented by the following correlation equation (1) holds for these liquids having a relatively high surface tension (surface tension: 60-72 mN / m). FIG. 8 is a graph in which the experimental results using isopropanol and silicone oil are plotted with the vertical axis as D _wet / D ₀ and the horizontal axis as Re ^1/5 We ^1/4 , and the relative surface tensions of these are shown in FIG. It has been shown that the relationship represented by the following correlation formula (1) holds for a low liquid (surface tension: about 20 mN / m). From FIGS. 7 and 8, it can be seen that D _wet / D ₀ is proportional to Re ^1/5 We ^1/4 , and the offset value β is determined by the contact angle θ. The graph inserted in FIG. 7 shows the relationship between each contact angle θ and the offset value β.

From these, the maximum wet spread diameter D _wet can be expressed by the following correlation equation (1).

In the above equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ and We = ρU ₀ ² D ₀ / σ, respectively. The proportionality coefficient α indicates the respective slopes in FIGS. 7 and 8, and changes depending on the liquid to be measured. The offset value β decreases monotonically as the contact angle θ increases, as shown in the graph inserted in FIG.

From the above, the viscous dissipation of the liquid affects not the maximum spread diameter D _max but the maximum wet spread diameter D _wet . Therefore, as the maximum diameter for calculating the viscous dissipation, the peripheral edge portion is from the surface of the collision portion 2. It is inappropriate to use the maximum diameter in the floating state (maximum spread diameter D _max ), and the maximum diameter of the region where the droplets that have reached the maximum spread diameter D _max are in contact with the surface of the collision part (maximum wet spread). It can be seen that it is necessary to use the diameter D _wet ).

Note that FIG. 9 is a graph obtained from the experimental results obtained by adding an aqueous glycerin solution (50 mPas) to the experimental results shown in FIGS. 7 and 8. From these, the maximum spread diameter D _max and the maximum wet spread diameter D _{wet of the} liquid are obtained. The relationship with can be shown by the following correlation equation (2).

(In equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. Reynolds number Re and Weber number We are Re = ρU ₀ D ₀ / μ, We = ρU ₀ ² D _{0, respectively.} / Σ.)

Here, as shown in FIG. 10, the proportional coefficient B can be expressed as a function of the ratio of the thickness h of the droplet to the thickness δ of the viscous boundary layer formed in the collision droplet, and h / If δ = x, it can be expressed as B = 3.634 x −1.349 ⁺ 0.5418. In addition, h / δ can be represented by the following equation (3) by dimensional analysis, and this is the horizontal axis in FIG.

Further, as a method of obtaining the maximum spread diameter D _max of the liquid, a method of experimentally measuring and a method of inferring from the maximum wet spread diameter D _wet using a correlation equation can be considered. In the method of experimental measurement, it is preferable to use a dub prism (a prism whose upper surface and lower surface are both flat and transparent) and perform both total reflection light photography and background light photography at the same time. In the method of inferring from the maximum wet spread diameter D _wet using the correlation formula, the experimental correlation formula is derived from the graph showing the relationship between the maximum wet spread diameter D _wet and the maximum spread diameter D _max based on the experimental results, and this experimental correlation is derived. It can be inferred from the equation from the maximum wet spread diameter D _wet . As an example, FIG. 11 (a) shows a graph _showing the relationship between the maximum wet spread diameter D _wet and the maximum spread diameter D _max when water is used, and FIG. 11 (b) shows the experimental correlation derived from (a). The formula is shown.

[Dripping mechanism]
The dropping mechanism 1 drops the liquid to be measured as a droplet D having a mass of M, and has a dropping portion 11 located at a predetermined height. The droplet D is dropped from the dropping portion 11 so as to freely fall. The configuration of the dropping mechanism 1 is not particularly limited as long as it can drop the liquid to be measured as droplets D from the dropping portion 11 so as to freely drop, and in the present embodiment, the liquid is dropped. In the dropping mechanism 1 having a syringe for filling, a syringe pump, and an injection needle (needle) connected to the syringe pump, the needle is used as the dropping portion 11.

[Collision part]
The collision portion 2 is for colliding the droplet D dropped from the dropping portion 11, and is provided so as to face the dropping portion 11. The material of the collision portion 2 is not particularly limited as long as it can cause the droplet D dropped from the dropping portion 11 to collide in a plane, but in the present embodiment, the collision portion 2 is as shown in FIG. A total reflection prism 21 having an incident surface 21a, an emitting surface 21b, and a reflecting surface 21c, and totally reflecting the laser beam incident from the incident surface 21a on the reflecting surface 21c and emitting the laser light from the emitting surface 21b is used.

When the droplet D collides with the collision portion 2 and spreads in a substantially circular shape, the peripheral portion of the droplet D deformed into a substantially circular shape is separated from the surface of the collision portion 2, or the peripheral portion is split and minute droplets are formed. If it does not scatter radially, that is, if the maximum spread diameter D _max and the maximum wet spread diameter D _wet are equal values, viscous dissipation even if an aluminum flat plate is used as the collision portion 2. The maximum diameter (maximum spread diameter D _max ) for calculating the above can be accurately measured by the third measuring device 33 described later. However, if the peripheral portion of the droplet D deformed into a substantially circular shape is separated from the surface of the aluminum flat plate, or if the peripheral portion is split and the minute droplets are scattered radially, the aluminum flat plate is used. Since it is very difficult to distinguish the maximum spread diameter D _max and the maximum wet spread diameter D _wet on the surface by the third measuring device 33, the maximum diameter for calculating the viscous dissipation (maximum wet spread diameter D _wet). ) Is difficult to measure accurately by the third measuring device 33.

In such a case, by using the total reflection prism 21 as the collision portion 2 as in the present embodiment, if the upper side of the reflection surface 21c of the total reflection prism 21 is air, the incident surface 21a is at a critical angle or higher. Since the laser light incident on the above is totally reflected, the reflected light can be obtained as a bright image in the third measuring device 33. On the other hand, since the refractive index of the liquid of the droplet D is higher than the refractive index of air, when the droplet D comes into contact with the reflecting surface 21c of the total reflection prism 21, the laser beam passes through the droplet D, so that the third droplet D is used. In the measuring device 33, the reflected light is obtained as a dark image.

FIG. 4 is a schematic view showing the principle of a method for measuring fluid motion near the surface pole of a prism using total reflection called the TIR (Total Internal Reflection) method, and FIG. 4A is a schematic diagram showing the reflection surface of the total reflection prism. (B) shows a schematic diagram showing how the intensity of reflected light from the wet region of the spreading droplets is attenuated, and (b) shows a schematic diagram of a wet region image in the direction along the emission surface of the total reflection prism. By using the TIR method, it is possible to measure the maximum wet spread diameter D _wet of the droplet D _{3 in} a state where the deformation into a substantially circular shape is reached to the maximum. When this method is used, the TIR image in the direction along the prism slope is reduced, so that the droplet image in the direction along the exit surface of the total reflection prism is actually an ellipse as shown in FIG. 5A. become.

As described above, since the collision portion 2 is the total reflection prism 21, the droplet D comes into contact with the portion in contact with the reflection surface 21c of the total reflection prism 21 based on the high-contrast image of the reflected light and the transmitted light. Since the non-existing part is clarified, the maximum wet spread diameter D _wet can be measured with high accuracy by the third measuring device 33. Therefore, when the droplet D collides with the collision portion 2 and spreads in a substantially circular shape, the peripheral portion of the droplet D deformed into a substantially circular shape collides due to reasons such as a sufficiently high collision speed of the droplet D. It is possible to accurately measure the viscosity of the liquid even when it is separated from the surface of the portion 2 or the peripheral portion is split and the minute droplets are scattered radially.

In the present embodiment, the total reflection prism 21 is arranged vertically separated from the dropping portion 11. The separation distance between the dropping portion 11 and the reflecting surface 21c of the total reflection prism 21 is preferably in the range of about 10 cm to 40 cm, and more preferably about 10 cm.

When the separation distance between the dropping portion 11 and the reflecting surface 21c of the total reflection prism 21 increases, the kinetic energy increases accordingly, but when the kinetic energy is too large, the droplet D acts on the reflecting surface 21c of the total reflection prism 21. Due to the impact of collision, the peripheral portion of the droplet D deformed into a substantially circular shape is split and the minute droplets are scattered radially, so-called splash is generated. If the splash causes the collision droplets to split into fine droplets at the periphery of the droplets too much, it may interfere with the measurement of the maximum wet spread diameter D _wet of the droplet D as described above. On the other hand, if the distance between the dropping portion 11 and the reflecting surface 21c of the total reflection prism 21 becomes smaller, the kinetic energy decreases accordingly, but if the kinetic energy is too small, it collides with the reflecting surface 21c of the total reflection prism 21. Since the resulting droplet D spreads and becomes in equilibrium only due to the above-mentioned wettability, there is a possibility that the measurement of the maximum wet spread diameter D _wet of the droplet D may be hindered. Therefore, it is necessary to appropriately set the separation distance between the dropping portion 11 and the collision portion 2 according to the liquid to be measured.

When the total reflection prism 21 is used as the collision portion 2, a slide glass is installed on the reflection surface 21c of the total reflection prism 21, and the droplet D dropped from the dropping portion 11 collides with the slide glass. You may let me. At this time, it is preferable to sandwich a thinly stretched glycerin between the reflecting surface 21c of the total reflection prism 21 and the slide glass in order to reduce the reflection and refraction of light by the air layer.

[First measuring device]
The first measuring device 31 is intended to, appended to the dropping portion 11, measures the contour shape S of the droplet D ₁ of the immediately prior to free fall. The structure of the first measuring device 31 is not particularly limited as long measured contour S of the droplet D _1, in the present embodiment, the first measuring device 31 having a long distance microscope and a digital camera connected to , based on the images taken with a digital camera movie recording (shooting speed 60 fps), seeking contour S of the droplet D _1. As the long-distance microscope and the digital camera, known or commercially available ones can be used. Further, in the present embodiment, the first measuring device 31, as shown in FIG. 1, a light source of LED lights and the like for irradiating the droplets D _1. The first measuring device 31 may further include a diffuser for sufficiently diffusing the light emitted from the light source.

Here, FIG. 11 is an image showing the measurement result of the first measuring device 31, (a) is an image taken by the digital camera of the first measuring device 31, (b) is an image of (a). (C) is an image obtained by extracting the contour shape S from the image of (b). Thus, in the present embodiment, the first measuring device 31, after binarized image of the droplet D ₁ taken by a digital camera, by extracting the contour of the binarized image, the liquid The contour shape S of the drop D ₁ is obtained.

[Second measuring device]
The second measuring device 32 sets the maximum horizontal diameter D ₀ of the droplet D ₂ at the measurement point A immediately before the collision of the total reflection prism 21 as the collision portion 2 with the reflecting surface 21c and the measurement point A into the droplet D ₂ The passage time ΔT required for the passage is measured. The configuration of the second measuring device 32 is not particularly limited as long as the maximum diameter D ₀ of the droplet D _{2 in} the horizontal direction at the measuring point A and the passing time ΔT through which the liquid drop D ₂ passes through the measuring point A can be measured. In the present embodiment, as the configuration of the second measuring device 32, the transmission is composed of a laser light source arranged at one position with the measurement point A in between and a laser receiver arranged at the other position. A type laser sensor is used.

Here, FIG. 13 is a waveform diagram showing a change in the behavior of the transmission type laser sensor of the second measuring device 32, and the vertical axis is the horizontal length of the droplet D ₂ detected by the transmission type laser sensor. , The horizontal axis is time. In addition, in FIG. 13, in order to facilitate understanding, the positional relationship between the transmissive laser sensor and the falling droplet D is shown in correspondence with the horizontal axis of the waveform diagram.

In the present embodiment, as shown in FIG. 14 (a), the second measuring device 32 obtains the droplet diameter and the passing speed based on the equation obtained by integrating the elliptical equation, and then shows in FIG. 14 (b). As described above, by fitting these values to the experimental values by the nonlinear least squares method with a, b, and U as variables, the maximum diameter D ₀ and the passage time ΔT of the droplet D ₂ passing through the measurement point A are obtained. ing. As described above, when only the laser sensor is used as the third measuring device 32, the maximum diameter D ₀ and the passing time ΔT can be measured with high accuracy, and compared with the case where the high-speed camera is used. It is possible to achieve a significant cost reduction as a whole. As the transmission type laser sensor, a known or commercially available one can be used.

Incidentally, when the liquid is the viscosity measurement object is transparent, would be a laser beam emitted from the transmission-type laser sensor is transmitted through the droplet D _2, as shown in FIG. 15, the maximum diameter D ₀ The corresponding output value (peak) may be lost. In this case, as shown in FIG. 14B, the output value corresponding to the maximum diameter D ₀ can be accurately obtained by interpolating the missing portion of the peak with an equation obtained by integrating the elliptical equation. ..

[Third measuring device]
The third measuring device 33 collides with the reflecting surface 21c of the total reflection prism 21 as the collision portion 2, and the maximum spreading diameter D _max and the maximum wetting of the droplet D _{3 in} a state where the deformation into a substantially circular shape is reached to the maximum. The spread diameter D _wet is measured. As described above, the droplet D that collides with the reflecting surface 21c of the total internal reflection prism 21 usually spreads in a substantially circular shape due to the inertial force as shown in FIG. 3, reaches the maximum spreading diameter D _max, and then faces the surface. It contracts in the returning direction due to tension or the like and becomes an equilibrium state, but under certain conditions such as when the collision speed of the droplet D is sufficiently high, as shown in FIG. 2, the droplet deformed into a substantially circular shape. The peripheral edge of D may be separated from the reflecting surface 21c of the total reflection prism 21, or the peripheral edge may be split and minute droplets may be scattered radially. In such a case, the maximum diameter for calculating the viscous dissipation is not the maximum diameter (maximum spread diameter D _max ) in the state where the peripheral edge portion is floating from the reflection surface 21c of the total reflection prism 21 as described above. As shown in FIGS. 2 and 4A, the maximum diameter of the region where the droplet D reaching the maximum spread diameter D _max is in contact with the reflection surface 21c of the total reflection prism 21 (maximum wet spread diameter D _wet ). Must be used.

According to the third measuring device 33, the peripheral portion of the droplet D deformed into a substantially circular shape is separated from the reflecting surface 21c of the total reflection prism 21, or the peripheral portion is split and the minute droplets are scattered radially. Even in this case, the maximum wet spread diameter D _wet of the droplet D ₃ can be measured with high accuracy based on the high-contrast image of the incident light and the transmitted light in the total reflection prism 21.

The structure of the third measuring device 33, shown in FIGS. 2 and 4 (a), the maximum spread diameter D _max and the maximum spreading diameter D of the droplet D ₃ in a state where deformation has reached a maximum to a substantially circular There is no particular limitation as long as the _wet can be measured. In the present embodiment, in determining the maximum spread diameter D _max , a high-contrast image of reflected light and transmitted light taken by a long exposure shown in FIG. 5A is used in a third measuring device 33 having a camera. , The maximum wet spread diameter D _wet is obtained based on the change in the brightness value on the red line shown in FIG. 5 (b). As described above, in this embodiment, the TIR method and the long exposure are used in combination.

As can be seen from the graph showing the change of luminance values in FIG. 5 (b), by using a long exposure image of the droplet D _3, it is possible to obtain the maximum spreading diameter D _wet with high contrast. The exposure time is not particularly limited as long as a high-contrast image can be obtained. The image shown in FIG. 5A was taken with an exposure time of 5 ms 27 ms after the droplet passed through the sheet laser of the laser sensor. The passing time and the exposure time are the height of the laser sensor. It is a value that changes depending on the laser. As the camera, a general-purpose industrial camera having a large number of pixels can be used.

As described above, when the camera is used as the third measuring device 33, a higher contrast image can be obtained, and a significant cost reduction as a whole is achieved as compared with the case where the high speed camera is used. It becomes possible to do. In the present embodiment, as shown in FIG. 1, the third measuring device 33 includes the third measuring device 33a for observing the very vicinity of the reflecting surface 21c of the total reflection prism 21 and the exit surface of the total reflection prism 21. It is composed of a third measuring device 33b for observing a direction along 21b. In this way, as shown in FIG. 4, the maximum wet spread diameter D _wet is measured with higher accuracy by observing the image of the droplet D on both the reflecting surface 21c and the emitting surface 21b of the total reflection prism 21. be able to.

Further, in the present embodiment, as shown in FIG. 1, the third measuring device 33 further includes a light source (not shown) for making the laser beam incident on the incident surface 21a of the total reflection prism 21. As the light source, for example, a green semiconductor laser can be used.

[Viscosity calculation device]
The viscosity calculation device (not shown) calculates the viscosity of the liquid to be measured based on the measurement result of the first measurement device 31, the measurement result of the second measurement device 32, and the measurement result of the third measurement device 33. is there. In the present embodiment, the viscosity calculation device includes a first calculation means, a second calculation means, and a third calculation means. The specific configuration of the viscosity calculation device will be described later together with the execution procedure.

(First calculation means)
The first calculation means calculates the volume V, the density ρ, and the surface tension σ of the droplet D based on the contour shape S and the mass M of the droplet D measured by the first measuring device 31. The method of calculating the volume V, the density ρ, and the surface tension σ of the droplet D by the first calculation means will be described in detail below with reference to FIG.

The volume V of the droplet D ₁ immediately before being suspended from the dropping portion 11 and free-falling is the same width and total height in the contour shape S shown in FIG. 8 (c) measured by the first measuring device 31. In the above, assuming a cylinder having a height of 1 pixel, the volume of this cylinder can be obtained, and these can be obtained by adding them together.

The density of the droplets D ₁ [rho can be determined from the mass M of previously measured droplet D and the volume V of the droplet D ₁ obtained by the above method.

The surface tension σ of the droplet D _1, the image shown in FIG. 11 (b), the maximum diameter d _e by combining the circularity on the outer diameter of the droplet D _1, the maximum diameter from the lowest end of the droplet D ₁ The diameter d _s at a position higher by the amount is measured, respectively, and based on the values of _de and d _s and the density ρ of the droplet D ₁ obtained by the above method, the surface is obtained from the balance between the hydrostatic pressure and the Laplace pressure by Fordham. The following equation (4) (Fordham, On the Certification of Surface Tension from Surface Drops, Proc. R. Soc. Land. A 194 (1948)) can be used to obtain the tension. ..

(In the formula (4), J represents a correction coefficient obtained from _d s / _{d e,} g is the acceleration of gravity.)

(Second calculation means)
The second calculating means calculates the collision speed U ₀ of the droplet D based on the maximum diameter D ₀ measured by the second measuring device 32, the passing time ΔT, and the volume V calculated by the first calculating means. .. The method of calculating the collision velocity U ₀ of the liquid drop model D by the second calculation means will be described in detail below with reference to FIG.

The collision velocity U ₀ of the droplet D ₂ is a slightly flat ball immediately before the collision shown in FIG. 3A from the maximum diameter D ₀ measured by the second measuring device 32 and the volume V calculated by the first calculation means. The height (maximum diameter in the vertical direction) h of the formed droplet D ₂ can be calculated, and can be obtained from this height h and the passing time ΔT measured by the second measuring device 32.

(Third calculation means)
The third calculation means includes the maximum diameter D ₀ measured by the second measuring device 32, the maximum wetting spread diameter D _wet measured by the third measuring device 33, the density ρ calculated by the first calculating means, and the second calculation. From the collision velocity U ₀ calculated by the means, the viscosity μ of the liquid to be measured is calculated by using the following correlation equation (1).

In the above equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ and We = ρU ₀ ² D ₀ / σ, respectively. The proportionality coefficient α indicates the respective slopes in FIGS. 7 and 8, and changes depending on the liquid to be measured. The offset value β decreases monotonically as the contact angle θ increases, as shown in the graph inserted in FIG.

Further, the third calculation means calculates the maximum diameter D ₀ measured by the second measuring device 32, the maximum spread diameter D _max and the maximum wet spread diameter D _wet measured by the third measuring device 33, and the first calculation means. From the calculated density ρ and the collision velocity U ₀ calculated by the second calculation means, the viscosity μ of the liquid to be measured may be calculated using the following correlation equation (2).

In the above equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ and We = ρU ₀ ² D ₀ / σ, respectively.

[Liquid viscosity measurement method]
Next, a method for measuring the viscosity of the liquid using the liquid viscosity measuring system 10 of the present embodiment as described above will be described with reference to FIG.

First, in order to drop the liquid to be measured as a droplet D having a mass M so as to freely fall from the dropping portion 11 located at a predetermined height, the droplet D is suspended from the tip of the needle as the dropping portion 11. ..

Next, the first measuring device 31, appended to the dropping portion 11, measures the contour shape S of the droplet D ₁ of the immediately prior to free fall (first measurement step).

After the first measurement step, the droplet D is dropped from the dropping portion 11 and freely dropped (dropping step). The second measuring device 32 sets the maximum horizontal diameter D ₀ of the droplet D ₂ at the measurement point A immediately before the collision of the total reflection prism 21 as the collision portion 2 with the reflection surface 21c and the measurement point A into the droplet D ₂ The passage time ΔT required for the passage is measured (second measurement step).

Immediately after the second measurement step, the droplet D collides with the reflecting surface 21c of the total reflection prism 21 arranged vertically separated from the dropping portion 11 (collision step).

After the collision process, the third measuring device 33, impinges on the reflection surface 21c of the total reflection prism 21, the maximum expansion diameter D _max and the maximum wetting of the droplet D ₃ in a state where deformation has reached a maximum to a substantially circular spread The diameter D _wet is measured (third measurement step). At this time, when the droplet D collides with the reflection surface 21c of the total reflection prism 21 and spreads in a substantially circular shape, the rim (edge) portion of the peripheral portion of the droplet D deformed into a substantially circular shape is the total reflection prism. When it is separated from the reflecting surface 21c of 21 or the rim portion is not split and the minute droplets are not scattered radially, the maximum spread diameter D _max and the maximum wet spread diameter D _wet are equal values.

After all the above steps are completed or in parallel with the above steps, the viscosity calculation device performs the viscosity calculation step as follows.

First, the first calculation means calculates the volume V, the density ρ, and the surface tension σ of the droplet D based on the contour shape S and the mass M of the droplet D measured in the first measurement step (first calculation step). ). Next, the second calculation means calculates the collision speed U _{0 of the} droplet D based on the maximum diameter D ₀ and the transit time ΔT measured in the second measurement step and the volume V calculated in the first calculation step. (Second calculation step).

Finally, the maximum diameter D ₀ measured in the second measurement step, the maximum wet spread diameter D _wet measured in the third measurement step, the density ρ calculated in the first calculation step, and the first calculation means by the third calculation means. 2 From the collision speed U ₀ calculated in the calculation step, the viscosity μ of the liquid to be measured is calculated using the following formula (1) (third calculation step).

In the above equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ and We = ρU ₀ ² D ₀ / σ, respectively. The proportionality coefficient α indicates the respective slopes in FIGS. 7 and 8, and changes depending on the liquid to be measured. The offset value β decreases monotonically as the contact angle θ increases, as shown in the graph inserted in FIG.

Further, in the third calculation step, the maximum diameter D ₀ measured in the second measurement step, the maximum spread diameter D _max and the maximum wet spread diameter D _wet measured in the third measurement step by the third calculation means, the first From the density ρ calculated in the calculation step and the collision velocity U ₀ calculated in the second calculation step, the viscosity μ of the liquid to be measured may be calculated using the following correlation equation (2). ..

In the above equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ and We = ρU ₀ ² D ₀ / σ, respectively.

In the present invention, the above-mentioned viscosity calculation step can be executed by a computer (for example, a general-purpose personal computer) by using it as a program, for example. This program is not particularly limited as long as the above viscosity calculation step is used, and may be created by using known means.

Hereinafter, a mode in which the above program is executed by a computer will be described with reference to FIGS. 16 and 17, but the present invention is not limited to the contents described in these drawings.

FIG. 16 is a block diagram showing a configuration of a viscosity calculation device included in the liquid viscosity measurement system 10 according to the embodiment of the present invention. The calculation unit 100 includes a CPU and is connected to an input unit 101, a storage unit 102, a program memory 103, and a display unit 104. The input unit 101 is composed of, for example, a keyboard, a touch panel, or the like, and is configured to be capable of inputting characters, numerical values, and the like. Further, the input unit 101 is directly or indirectly connected to three measuring devices (first measuring device 31, second measuring device 32, third measuring device 33), and measurement data transmitted from each measuring device. May be configured to be received by the input unit 101. The storage unit 102 stores predetermined information when using the program. The program memory 103 stores an operation program including mathematical formula data such as the above equations (1), (2) and (3). The calculation unit 100 applies the measurement data input by the input unit 101 to a mathematical formula or the like stored in the program memory 103 to calculate the viscosity of the liquid.

FIG. 17 is a flowchart showing the execution procedure of the above program. First, the measurement data of the three measuring devices (the first measuring device 31, the second measuring device 32, and the third measuring device 33) are input (201). If the input measurement data is incompatible, an error will occur and the input will be re-entered. Next, the input measurement data is applied to the above formula (1) or the like in the above-mentioned viscosity calculation step to calculate the viscosity of the liquid (202). Specifically, the first calculation step is first performed based on the input measurement data, and then the second calculation step is performed by adding the calculation data obtained in the first calculation step. Further, the calculation data obtained in the first calculation step and the calculation data obtained in the second calculation step are added, and the third calculation step is performed using the above formula (1). At this time, if the calculation result is, for example, a negative value, an error occurs and the input is restarted. If the calculation result is normal, the calculation result is displayed (203).

In the above-described embodiment, an example in which the functional block shown in FIG. 16 is realized mainly by software by a CPU program has been described, but even if it is realized mainly by hardware by electronic components. Good.

Although the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the measurement is performed by long-time exposure using a camera as the third measuring device 33, but the measurement is not limited to this, and for example, a long-range microscope like the first measuring device 31. And a high-speed camera connected to this may be used. Further, in the above embodiment, as the second measuring device 32, the transmission is composed of a laser light source arranged at one position with the measurement point A in between and a laser receiver arranged at the other position. Only the type laser sensor is used, but the present invention is not limited to this, and for example, using a high-speed camera, the value of the horizontal length of the droplet D ₂ that has passed the measurement point A from the waveform diagram shown in FIG. The maximum diameter D ₀ may be obtained based on the maximum value of the above values, and the passing time ΔT may be obtained from the time required for the droplet D ₂ to pass through the measurement point A. Further, in the viscosity measuring system 10, the entire viscosity measuring system 10 is installed in the glove box from the viewpoint of preventing the occurrence of measurement error of the droplet D due to the influence of external force such as vibration, lifting force, and wind on the dropping portion 11. It may be a thing.

As described above, according to the liquid viscosity measuring system and the liquid viscosity measuring method of the present invention, the first measuring means, the first measuring means, takes only a short time until the liquid is freely dropped as droplets and collides with the collision portion. The viscosity of the liquid can be measured from the measurement results of the second measuring means and the third measuring means. As a result, even if the liquid to be measured has coagulability such as blood, paint, and adhesive, and many physical properties such as metal and glass are strongly affected by the surrounding environment such as temperature and oxygen concentration. Even if there is, accurate viscosity measurement is possible. Further, since the viscosity of the liquid can be measured with an extremely small sample amount of one drop, it can be used for measuring the viscosity of a liquid for which it is difficult to prepare a sufficient sample amount, and it is highly versatile.

Then, since the collision portion is a total reflection prism, it is clarified where the droplets are in contact with the reflection surface of the total reflection prism and where they are not in contact, based on the high-contrast image of the reflected light and the transmitted light. Therefore, the maximum wet spread diameter D _wet can be measured with high accuracy by the third measuring means. Therefore, when the droplet collides with the surface of the collision portion and spreads in a substantially circular shape, the peripheral portion of the droplet deformed into a substantially circular shape is the collision portion because the collision speed of the droplet is sufficiently high. It is possible to accurately measure the viscosity of a liquid even when it is separated from the surface or the peripheral portion is split and minute droplets are scattered radially.

The present invention is particularly useful as a system and method for measuring the viscosity of coagulating liquids such as blood, paints and adhesives, and refractory materials such as metals and glass. In addition, it is useful because the viscosity, surface tension, and density, which are the main physical properties of a liquid, which conventionally require separate measuring instruments, can be obtained by one measurement.

10 Liquid viscosity measurement system 1 Drop mechanism 11 Drop mechanism 2 Drop part 2 Collision part 21 Total reflection prism 21a Incident surface 21b Exit surface 21c Reflection surface 31 First measurement device 32 Second measurement device 33 Third measurement device A Droplet D immediately before collision Measurement point D (D ₁ , D ₂ , D ₃ ) Droplet D ₀ Maximum horizontal diameter of droplet D immediately before collision D _max Maximum spread diameter of droplet D after collision D _Wet Droplet D after collision Maximum wet spread diameter

Claims (16)

A dropping means for dropping a liquid as a droplet having a mass of M so as to freely fall from a dropping portion located at a predetermined height.
A collision portion provided so as to face the dropping portion and for colliding the droplet dropped from the dropping portion,
A first measuring means for measuring the state of the droplet at the time of dropping from the dropping portion,
A second measuring means for measuring the state of the droplet immediately before the collision with the collision portion,
A third measuring means for measuring the state of the droplet after colliding with the collision portion,
A viscosity calculating means for calculating the viscosity of the liquid based on the measurement result of the first measuring means, the measuring result of the second measuring means, and the measuring result of the third measuring means is provided.
The collision portion is a total reflection prism having an incident surface, an emitting surface, and a reflecting surface, and totally reflects the laser light incident from the incident surface on the reflecting surface and emits it from the emitting surface.
The third measuring means collides with the reflecting surface of the total internal reflection prism and measures the maximum spread diameter D _max and the maximum wet spread diameter D _wet of the droplet deformed into a substantially circular shape. system. The liquid viscosity measuring system according to claim 1, wherein the first measuring means suspends the dropping portion and measures the contour shape S of the droplet immediately before it falls freely. Wherein the second measuring means, the transit time ΔT required for the droplet to the maximum diameter D ₀ and the measuring point in the horizontal direction of the liquid droplet at the measurement point immediately before the collision to the reflecting surface of the total reflection prism passes The liquid viscosity measuring system according to claim 1 or 2, which is to be measured. The first measuring means suspends the dropping portion and measures the contour shape S of the droplet immediately before it falls freely.
Wherein the second measuring means, the transit time ΔT required for the droplet to the maximum diameter D ₀ and the measuring point in the horizontal direction of the liquid droplet at the measurement point immediately before the collision to the reflecting surface of the total reflection prism passes To measure
The viscosity calculation means
A first calculating means for calculating the volume V, density ρ, and surface tension σ of the droplet based on the contour shape S and the mass M measured by the first measuring means.
A claim including a second calculating means for calculating the collision speed U _{0 of the} droplet based on the maximum diameter D ₀ and the passing time ΔT measured by the second measuring means and the volume V calculated by the first calculating means. Item 1. The liquid viscosity measuring system according to Item 1. The viscosity calculating means includes a maximum diameter D ₀ measured by the second measuring means, a maximum wet spread diameter D _wet measured by the third measuring means, a density ρ calculated by the first calculating means, and the first. 2. The liquid viscosity measuring system according to claim 4, further comprising a third calculating means for calculating the viscosity μ of the liquid from the collision speed U ₀ calculated by the calculating means using the following correlation formula (1).

(In equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ, We =, respectively. ρU ₀ ² D ₀ / σ.) The viscosity calculation means is calculated by the first calculation means, the maximum diameter D ₀ measured by the second measuring means, the maximum spread diameter D _max and the maximum wet spread diameter D _wet measured by the third measuring means. The liquid according to claim 4, further comprising a third calculation means for calculating the viscosity μ of the liquid using the following correlation formula (2) from the density ρ and the collision speed U ₀ calculated by the second calculation means. Viscosity measurement system.

(In equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. Reynolds number Re and Weber number We are Re = ρU ₀ D ₀ / μ, We = ρU ₀ ² D _{0, respectively.} / Σ.) The liquid viscosity measuring system according to any one of claims 1 to 6, wherein the liquid is a liquid having coagulation properties. The liquid viscosity measuring system according to any one of claims 1 to 6, wherein the liquid is a liquid of a material having a high melting point. A dropping step of dropping a liquid as a droplet having a mass of M so as to freely fall from a dropping portion located at a predetermined height.
A collision step in which the droplets dropped from the dropping portion collide with a collision portion provided so as to face the dropping portion.
The first measurement step of measuring the state of the droplet at the time of dropping from the dropping portion, and
A second measurement step of measuring the state of the droplet immediately before the collision with the collision portion, and
A third measurement step of measuring the state of the droplet after colliding with the collision portion,
It includes a measurement result obtained in the first measurement step, a measurement result obtained in the second measurement step, and a viscosity calculation step of calculating the viscosity of the liquid based on the measurement result obtained in the third measurement step. ,
The collision portion is a total reflection prism having an incident surface, an emitting surface, and a reflecting surface, and totally reflects the laser light incident from the incident surface on the reflecting surface and emits it from the emitting surface.
The third measurement step measures the maximum spread diameter D _max and the maximum wet spread diameter D _wet of the droplets that collide with the reflection surface of the total reflection prism and are deformed into a substantially circular shape. Method. The method for measuring the viscosity of a liquid according to claim 9, wherein the first measuring step measures the contour shape S of the droplet immediately before the droplet is suspended from the dropping portion and freely dropped. The second measurement step, the transit time ΔT required for the droplet to the maximum diameter D ₀ and the measuring point in the horizontal direction of the liquid droplet at the measurement point immediately before the collision to the reflecting surface of the total reflection prism passes The method for measuring the viscosity of a liquid according to claim 9 or 10, which is to be measured. The first measuring step measures the contour shape S of the droplet immediately before it is suspended from the dropping portion and freely dropped.
The second measurement step, the transit time ΔT required for the droplet to the maximum diameter D ₀ and the measuring point in the horizontal direction of the liquid droplet at the measurement point immediately before the collision to the reflecting surface of the total reflection prism passes To measure
The viscosity calculation step
A first calculation step of calculating the volume V, density ρ, and surface tension σ of the droplet based on the contour shape S and the mass M measured in the first measurement step.
A claim including a second calculation step of calculating the collision speed U _{0 of the} droplet based on the maximum diameter D ₀ and the passing time ΔT measured in the second measurement step and the volume V calculated in the first calculation step. Item 9. The method for measuring the viscosity of a liquid according to Item 9. In the viscosity calculation step, the maximum diameter D ₀ measured in the second measurement step, the maximum wet spread diameter D _wet measured in the third measurement step, the density ρ calculated in the first calculation step, and the first calculation step. 2. The method for measuring the viscosity of a liquid according to claim 10, further comprising a third calculation step of calculating the viscosity μ of the liquid from the collision speed U ₀ calculated in the calculation step using the following correlation formula (1).

(In equation (1), We is the Weber number, Re is the Reynolds number, α is the proportional coefficient, and β is the offset value. The Reynolds number Re and the Weber number We are Re = ρU ₀ D ₀ / μ, We =, respectively. ρU ₀ ² D ₀ / σ.) The viscosity calculation step is calculated by the maximum diameter D ₀ measured in the second measurement step, the maximum spread diameter D _max and the maximum wet spread diameter D _wet measured in the third measurement step, and the first calculation step. The liquid according to claim 10, further comprising a third calculation step of calculating the viscosity μ of the liquid using the following correlation formula (2) from the density ρ and the collision speed U ₀ calculated in the second calculation step. Viscosity measurement method.

(In equation (2), We is the Weber number, Re is the Reynolds number, and B is the proportional coefficient. Reynolds number Re and Weber number We are Re = ρU ₀ D ₀ / μ, We = ρU ₀ ² D _{0, respectively.} / Σ.) The method for measuring the viscosity of a liquid according to any one of claims 9 to 13, wherein the liquid is a liquid having coagulation properties. The method for measuring the viscosity of a liquid according to any one of claims 9 to 13, wherein the liquid is a liquid of a material having a high melting point.