JP6959635B2 - Liquid viscosity measurement system and liquid viscosity measurement method - Google Patents

Description

The present invention relates to a liquid viscosity measuring system and a liquid viscosity measuring method, and in particular, a liquid viscosity measuring system and a liquid capable of easily measuring the viscosity of a coagulable liquid such as blood, paint, and adhesive. Regarding the viscosity measurement method of.

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. be. 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 freely drops a cylindrical or spherical rigid body having a certain size and density in a liquid sample, and obtains the viscosity based on the time required for dropping a certain distance. The vibration type viscosity measuring instrument has been used in recent years, and obtains the viscosity of a liquid from a driving current for vibrating a vibrator inserted in a liquid sample with a constant amplitude.

However, the conventional viscosity measuring instrument as described above has a complicated structure, is difficult to operate, and the measuring instrument itself is 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 coagulated 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. 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. A flat plate-shaped collision portion for colliding the droplets dropped from the dropping portion, a first measuring means for measuring the state of the droplets when dropped from the dropping portion, and the flat plate-shaped collision portion. A second measuring means for measuring the state of the droplet immediately before the collision with the liquid, a third measuring means for measuring the state of the droplet after the collision with the flat plate-shaped collision portion, and a measurement result of the first measuring means. Provided is a liquid viscosity measuring system including a measurement result of the second measuring means and a viscosity calculating means for calculating the viscosity of the liquid based on the measurement result of the third measuring means (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 take a short time until the liquid is freely dropped as a droplet and collides with the flat plate-shaped collision portion. Therefore, the viscosity of the liquid can be measured. As a result, even if the liquid to be measured has coagulability such as blood, paint, or adhesive, accurate viscosity measurement can be performed without being affected by the coagulation property. 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 the versatility is high.

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 free fall (Invention 2).

In the above inventions (Inventions 1 and 2), the second measuring means causes the droplet to set the maximum horizontal diameter D _{0 of the droplet at the measuring point immediately before the collision with the flat plate-shaped collision portion and the measuring point.} It is preferable to measure the passing time ΔT required for passing (Invention 3).

_{In the above invention (Invention 1-3), the third measuring means measures the maximum spread diameter D max} of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape. Preferred (Invention 4).

Note that FIG. 4 is a schematic view showing a change in the state of the droplets that have collided with the flat plate-shaped collision portion. FIG. 4A is a state immediately before the collision, and FIG. The state of being deformed, (c) shows the state where the deformation to a substantially circular shape is reached to the maximum, and (d) shows the state where after (c), it contracts in the return direction due to surface tension or the like and reaches equilibrium. ing. In the present invention, the maximum spread diameter D _{max of} the droplet means the maximum diameter of the droplet deformed into a substantially circular shape in the state shown in FIG. 4 (c).

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. is for measuring the transit time ΔT takes a 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 flat collision part in the droplet passes, the viscosity calculating means Is measured by the first calculating 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 measuring means, and the second measuring means. It is preferable to provide a second calculation means for calculating the collision speed U of the droplet based on the maximum diameter D _{0, the passage time ΔT, and the volume V calculated by the first calculation means (Invention 5).}

Conventionally, a dedicated measuring instrument is used for measuring the viscosity, density, and surface tension, which are the main physical characteristics of a liquid. According to the present invention (Invention 5), 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.

（式（１）中、Ｗｅはウェーバ数、Ａは固体平面の濡れ性等によって変化する補正係数である。） In the above invention (Invention 5), the third measuring means measures the maximum spread diameter D _max of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape, and calculates the viscosity. The means are the maximum diameter D _{0 measured by the second measuring means, the maximum spread diameter D max} measured by the third measuring means, the density ρ calculated by the first calculating means, and the second calculating means. It is preferable to further provide a third calculation means for calculating the viscosity μ of the liquid from the calculated collision velocity U using the following formula (1) (Invention 6).

(In equation (1), We is the Weber number, and A is the correction coefficient that changes depending on the wettability of the solid plane.)

According to the invention (Invention 6), the viscosity of the liquid to be measured can be determined by using the above formula (1).

Secondly, the present invention has 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 flat plate-shaped collision portion provided facing the dropping portion. , A collision step of colliding the droplets dropped from the dropping portion, a first measuring step of measuring the state of the droplets at the time of dropping from the dropping portion, and the liquid immediately before colliding with the flat plate-shaped collision portion. The second measurement step of measuring the state of the droplet, the third measurement step of measuring the state of the droplet after the collision with the flat plate-shaped collision portion, and the measurement result obtained in the first measurement step, the second Provided is a method for measuring the viscosity of a liquid, which comprises a measurement result obtained in the 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 (Invention 7).

In the above invention (Invention 7), 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 8).

In the above inventions (Inventions 7 and 8), in the second measurement step, the droplet has the maximum horizontal diameter D _{0 of the droplet at the measurement point immediately before the collision with the flat plate-shaped collision portion and the measurement point.} It is preferable to measure the transit time ΔT required for passage (Invention 9).

_{In the above invention (Invention 7-9), the third measurement step measures the maximum spread diameter D max} of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape. Preferred (Invention 10).

In the above invention (Invention 7), 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. is for measuring the transit time ΔT takes a 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 flat collision part in the droplet passes, the viscosity calculation step Is measured in 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 of the droplet based on the maximum diameter D _{0, the passing time ΔT, and the volume V calculated in the first calculation step (Invention 11).}

（式（１）中、Ｗｅはウェーバ数、Ａは固体平面の濡れ性等によって変化する補正係数である。） In the above invention (Invention 11), the third measurement step measures the maximum spread diameter D _max of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape, and calculates the viscosity. The steps include the maximum diameter D _{0 measured in the second measurement step, the maximum spread diameter D max} measured in the third measurement step, the density ρ calculated in the first calculation step, and the second calculation step. It is preferable to further include a third calculation step of calculating the viscosity μ of the liquid from the calculated collision speed U using the following formula (1) (Invention 12).

(In equation (1), We is the Weber number, and A is the correction coefficient that changes depending on the wettability of the solid plane.)

According to the liquid viscosity measuring system and the liquid viscosity measuring method of the present invention, the measuring time is shorter than that of the conventional viscosity measuring instrument, and the viscosity is easily and accurately measured even if the required sample amount is small. be able to.

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. 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. be. It is a schematic diagram which shows the state change of the droplet which collided with a flat plate-shaped collision part. FIG. (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 return direction due to surface tension or the like and reaches equilibrium. 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 view 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 flat plate-shaped collision portion 2, a first measuring device 31, a second measuring device 32, a third measuring device 33, and a viscosity calculating device (non-standard). Mainly provided (shown). In the following, for ease of description, appended to the dropping portion 11, a collision the droplets D immediately before the free fall D _1, the droplets D of the immediately preceding a collision D _2, the plate-like collision portion 2 and, the droplets D in a state where the deformation of the substantially circular shape has reached the maximum may be referred to D _3.

[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 the liquid to be measured can be dropped freely as droplets D from the dropping portion 11, 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.

[Plate-shaped collision part]
The flat plate-shaped 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 flat plate-shaped collision portion 2 is not particularly limited as long as it can collide the droplet D dropped from the dropping portion 11 in a plane, and for example, an aluminum flat plate can be used. The contact angle θ when the liquid droplet D to be measured is formed on the solid plane is determined by the type of material of the flat plate-shaped collision portion 2, and the wettability is evaluated based on this contact angle θ. The correction coefficient A in the equation (1) described later changes depending on the sex.

In the present embodiment, the flat plate-shaped collision portion 2 is arranged vertically separated from the dropping portion 11. The separation distance between the dropping portion 11 and the flat plate-shaped collision portion 2 is preferably in the range of approximately 10 cm to 40 cm.

When the separation distance between the dropping portion 11 and the flat plate-shaped collision portion 2 increases, the kinetic energy increases accordingly, but when the kinetic energy is too large, the impact of the droplet D colliding with the flat plate-shaped collision portion 2, so-called A splash may occur and the peripheral edge of the collision droplet may be split into fine droplets, which may interfere with the measurement of _{the maximum spread diameter D max of the droplet D.} On the other hand, when the separation distance between the dropping portion 11 and the flat plate-shaped collision portion 2 becomes small, the kinetic energy decreases accordingly, but when the kinetic energy is too small, the droplet D colliding with the flat plate-shaped collision portion 2 is generated. Since the spread and equilibrium state is reached only by the above-mentioned wettability, there is a possibility that the measurement of _{the maximum spread diameter D max of the droplet D may be hindered.} Therefore, the separation distance between the dropping portion 11 and the flat plate-shaped collision portion 2 is appropriately set according to the liquid to be measured.

[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 having a high-speed camera connected long distance microscope and thereto 31 in, on the basis of the image taken by the high-speed camera, seeking contour S of the droplet D _1. As the long-range microscope and the high-speed camera, known or commercially available ones can be used. Further, in the present embodiment, the first measuring device 31, as shown in FIG. 1, to sufficiently diffuse the light emitted a white light source such as a metal halide lamp from the white light source for irradiating the liquid droplets D ₁ It also has a diffuser for.

Here, FIG. 2 is an image measured by the first measuring device 31, (a) is an image taken by the high-speed camera of the first measuring device 31, and (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, after the binarized image of the droplet D ₁ taken by the high-speed camera according to the first measuring device 31, by extracting the contour of the binarized image, seeking contour S of the droplet D _1.

[Second measuring device]
The second measuring device 32 has a horizontal maximum diameter D _{0 of the droplet D 2} at the measurement point A immediately before the collision with the flat plate-shaped collision portion 2 and a passing time required for the droplet D ₂ to pass through the measurement point A. It measures ΔT. The configuration of the second measuring device 32 is not particularly limited as long measured transit time ΔT of the maximum diameter D ₀ and the measurement point A in the horizontal direction of the droplet D ₂ passes droplet D ₂ at the measurement point A. 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. 3 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 the present embodiment, the second measuring device 32 _{obtains the maximum diameter D 0} and the passing time ΔT from the waveform diagram. More specifically, determine the maximum diameter D _0, based on the maximum value of the horizontal length of the value of the droplet D ₂ passing through the measurement point A, the measurement point A droplet D ₂ passes The transit time ΔT is calculated from the time required for. As the transmission type laser sensor, a known or commercially available one can be used.

[Third measuring device]
The third measuring device 33 measures the maximum spread diameter D _max of _{the droplet D 3 in} a state where it collides with the flat plate-shaped collision portion 2 and the deformation into a substantially circular shape is reached to the maximum. As shown in FIG. 4, the droplet D that collides with the flat plate-shaped collision portion 2 spreads in a substantially circular shape due to inertial force _{, reaches the maximum spread diameter D max} , and then contracts in the return direction due to surface tension or the like. Is in equilibrium.

The configuration of the third measuring device 33 is particularly limited as long as it can measure the maximum spread diameter D _{max of the droplet D 3 in} a state where the deformation into a substantially circular shape is reached to the maximum, as shown in FIG. 4 (c). However, in the present embodiment, similarly to the first measuring device 31, the maximum spread diameter is based on the image taken by the high-speed camera in the third measuring device 33 having the long-range microscope and the high-speed camera connected thereto. We are looking for D _max. As the high-speed camera, a known or commercially available one can be used. Further, in the present embodiment, the third measuring device 33, as shown in FIG. 1, to sufficiently diffuse the white light source and light emitted from the white light source of a metal halide lamp or the like for irradiating the liquid droplets D ₃ It also has a diffuser for.

[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. be. 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. 2 (c) measured by the first measuring device 31. In the above, assuming a cylinder having a height of 1 pix, 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.

（式（２）中、Ｊはｄ_ｓ／ｄ_ｅから求められる補正係数であり、ｇは重力加速度である。） The surface tension σ of the droplet D _1, the image shown in FIG. 2 (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 (2) (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 (2), J is a correction coefficient determined from _d s / _{d e,} g is the acceleration of gravity.)

(Second calculation means)
_{The second calculating means calculates the collision speed U 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 of the droplet D by the second calculation means will be described in detail below with reference to FIG.

The collision speed U of the droplet D ₂ is a slightly oblate sphere immediately before the collision shown in FIG. 4A from _{the maximum diameter D 0} measured by the second measuring device 32 and the volume V calculated by the first calculating means. The height (maximum diameter in the vertical direction) h of the droplet D ₂ can be calculated and obtained from this height h and the transit time ΔT measured by the second measuring device 32.

上記式（１）中、Ｗｅはウェーバ数、Ａは固体平面の濡れ性等によって変化する補正係数であり、ウェーバ数Ｗｅは、Ｗｅ＝ρＵ^２Ｄ_０／σである。 (Third calculation means)
The third calculation means includes the maximum diameter D _{0 measured by the second measuring device 32, the maximum spread diameter D max} measured by the third measuring device 33, the density ρ calculated by the first calculation means, and the second calculation means. From the collision speed U calculated by the above method, the viscosity μ of the liquid to be measured is calculated using the following formula (1).

In the above equation (1), We is the Weber number, A is a correction coefficient that changes depending on the wettability of the solid plane, and the Weber number We is We = ρU ² D ₀ / σ.

具体的手法としては、第３測定装置３３のハイスピードカメラで撮影した、図４（ｄ）に示す、衝突後に表面張力等によって戻る方向に収縮し、平衡に達した状態の液滴Ｄの画像から、液滴の接触角θを求め、この接触角θから、上記式（３）を用いて、補正係数Ａを求めることができる。 The correction coefficient A in the above equation (1) is defined by Zhang et al. The following equation (3) (Zhang et al., On the sprading of interacting drops under the influence of a virtual magnetic field, J. , Vol.809, R3 (2016), pp.1-13).

As a specific method, an image of the droplet D in a state of being contracted in the return direction due to surface tension or the like after the collision and reaching equilibrium, as shown in FIG. 4D, taken by the high-speed camera of the third measuring device 33. From this, the contact angle θ of the droplet can be obtained, and from this contact angle θ, the correction coefficient A can be obtained using the above equation (3).

上記（４）式中、レイノルズ数Ｒｅとウェーバ数Ｗｅはそれぞれ、Ｒｅ＝ρＵＤ_０／μ，Ｗｅ＝ρＵ^２Ｄ_０／σである。 Further, the above formula (1) is expressed by Laan et al. The following correlation equation (4) (Laan, et al., Maximum Diameter of Implementing Liquid Droplets, Phys. Rev. Applied 2,044018 (2014), pp. 1-7) regarding the maximum diameter of the collision droplets according to It can be obtained by solving about.

In the above equation (4), the Reynolds number Re and the Weber number We are Re = ρUD ₀ / μ and We = ρU 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 FIGS. 1-3.

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). By the second measuring device 32, passes the time required horizontal maximum diameter D ₀ and the measurement point A of the droplet D ₂ at the measurement point A immediately before collision of the flat collision part 2 to pass through droplet D ₂ ΔT is measured (second measurement step).

Immediately after the second measurement step, the droplet D collides with the flat plate-shaped collision portion 2 arranged vertically separated from the dropping portion 11 (collision step).

After the collision step, the third measuring device 33 measures the maximum spread diameter D _{max of the droplet D 3 in} a state where it collides with the flat plate-shaped collision portion 2 and the deformation into a substantially circular shape is reached to the maximum (third measurement). Process).

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, density ρ, and 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 of the droplet D based on the maximum diameter D 0} measured in the second measurement step, the transit time ΔT, and the volume V calculated in the first calculation step ( Second calculation process).

上記式（１）中、Ｗｅはウェーバ数、Ａは固体平面の濡れ性等によって変化する補正係数であり、ウェーバ数Ｗｅは、Ｗｅ＝ρＵ^２Ｄ_０／σである。 _{Finally, the maximum diameter D 0} measured in the second measurement step, _{the maximum spread diameter D max} measured in the third measurement step, the density ρ calculated in the first calculation step, and the second calculation means by the third calculation means. From the collision speed U 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, A is a correction coefficient that changes depending on the wettability of the solid plane, and the Weber number We is We = ρU ² D ₀ / σ.

In the present invention, the above-mentioned viscosity calculation step can be executed by a computer (for example, a general-purpose personal computer or the like) 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. 5 and 6, but the present invention is not limited to the contents described in these drawings.

FIG. 5 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. 6 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 will occur and the input will be 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. 5 is realized mainly by software by a CPU program has been described, but even if it is realized mainly by hardware by an electronic component. good.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples.

The viscosity of the liquid was measured using the viscosity measuring system 10 shown in FIG. A glycerin aqueous solution was used as a measurement target, and the viscosities were measured under 36 conditions obtained by combining 6 glycerin aqueous solutions, 3 needle diameters, and 2 droplet drop heights. For each parameter, in order to reduce the statistical uncertainty, measurement was performed 10 times for each liquid sample.

In this example, a certain amount of liquid sample was dropped as droplets from an injection needle (needle) connected to a syringe pump and collided with an aluminum flat plate at a collision angle of 90 degrees. At that time, a long-range microscope ( _{D 1} ) shows the state of the droplet (D 1) immediately before it is suspended from the needle and falls freely, _{and the state of the droplet (D 3} ) that collides with the aluminum flat plate and is deformed in the radial direction. The image was taken with a high-speed camera (Vision Research, Phantom V9.1) connected to a Navitar, 12 x zoom). The shooting speed of the high-speed camera was 4000 fps. Further, using a transmission laser sensor (Keyence, IB.10) and a data logger provided at a position immediately before the droplet collides with the aluminum flat plate, _{the maximum diameter of the droplet (D 2} ) immediately before the collision in the horizontal direction is used. D ₀ and the passage time ΔT required for the droplet D _{2 to pass through the transmission laser sensor were measured.} The sampling rate of the data logger was 12500 Hz.

Next, each physical quantity for obtaining the viscosity μ of the liquid was calculated using the viscosity calculation device described above. Here, the volume and surface tension of the liquid droplet were calculated by suspending the liquid droplet on the needle and _{processing the photographed image of the droplet (D 1} ) immediately before the free fall with MATLAB Image Processing Toolbox (registered trademark).

Table 1 shows a comparison between the viscosity of the liquid sample calculated from the above collision experiment (experimental value) and the viscosity of the liquid sample measured by the conventional Ostwald viscometer (actual measurement value).

From the results shown in Table 1, according to the liquid viscosity measurement system and method according to the present invention, the measurement time is shorter than that of the conventional viscosity measuring instrument, and even if the required sample amount is small, the viscosity is easily and accurately obtained. It can be seen that can be measured.

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, a long-range microscope and a long-range microscope are used as a third measuring device for measuring the maximum spread diameter D _{max of the droplet D 3} that has collided with the flat plate-shaped collision portion 2 and is deformed into a substantially circular shape. A connected high-speed camera is used, but the present invention is not limited to this, and for example, a means to which a visualization method using total reflection on the upper surface of the prism is applied may be used. In this method, when the upper surface of the prism is air, the laser beam incident on the critical angle or higher is totally reflected, so that a bright image can be obtained on the camera sensor. On the other hand, when the droplet D comes into contact with the prism, the refractive index of the liquid is higher than the refractive index of the gas, so that the light passes through the droplet and the reflected light on the camera sensor becomes dark. This makes it possible to clearly distinguish between the portion where the droplet D is in contact with the solid (prism) and the portion where the droplet D is not in contact with the solid (prism). Further, the entire viscosity measuring system 10 may be 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, lift, and wind on the dropping portion 11. ..

As described above, according to the liquid viscosity measurement system and the liquid viscosity measurement method of the present invention, the first measurement is performed in a short time until the liquid is freely dropped as droplets and collides with the flat plate-shaped collision portion. The viscosity of the liquid can be measured from the measurement results of the device, the second measuring device, and the third measuring device. As a result, even if the liquid to be measured has coagulability such as blood, paint, or adhesive, accurate viscosity measurement can be performed without being affected by the coagulation property. 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 the versatility is high.

The present invention is particularly useful as a system and method for measuring the viscosity of coagulating liquids such as blood, paints and adhesives. In addition, it is useful because the viscosity, surface tension, and density, which are the main physical characteristics 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 part 2 Flat plate collision part 31 First measurement device 32 Second measurement device 33 Third measurement device A Measurement point D (D ₁ , D ₂ , ,) of droplet D immediately before collision D ₃ ) Droplet D ₀ Maximum horizontal diameter of droplet D immediately before _{collision D max} Maximum spread diameter of droplet D after collision

Claims (6)

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 flat plate-shaped collision portion provided so as to face the dropping portion and for colliding the droplets dropped from the dropping portion, and a flat plate-shaped collision portion.
A first measuring means for measuring the contour shape S of the droplet immediately before being suspended from the dropping portion and free-falling.
A second measuring means 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 flat collision part,
A third measuring means for measuring _{the maximum spread diameter D max} of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape.
A liquid viscosity measuring system including a measuring result of the first measuring means, a measuring result of the second measuring means, and a viscosity calculating means for calculating the viscosity of the liquid based on the measuring result of the third measuring means. The previous Symbol viscosity calculating 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 comprising a second calculating means for calculating the collision speed U of the droplet based on the maximum diameter D 0} measured by the second measuring means, the passing time ΔT, and the volume V calculated by the first calculating means. The liquid viscosity measuring system according to 1. Previous SL viscosity calculation means, said second maximum diameter D ₀ is measured by the measuring _means, the third largest spread diameter D _max measured by the measuring _means, first by density ρ and the calculation by the first calculating means 2. The liquid viscosity measuring system according to claim 2 , further comprising a third calculating means for calculating the viscosity μ of the liquid from the collision speed U calculated by the calculating means using the following formula (1).

(In equation (1), We is the Weber number, and A is the correction coefficient that changes depending on the wettability of the solid plane.) A dropping step in which a liquid is dropped 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 flat plate-shaped collision portion provided so as to face the dropping portion.
The first measuring step of suspending the dropping portion and measuring the contour shape S of the droplet immediately before the free fall, and the first measuring step.
A second measuring step of 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 flat collision part,
A third measurement step of measuring _{the maximum spread diameter D max} of the droplet that collides with the flat plate-shaped collision portion and is deformed into a substantially circular shape.
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. Liquid viscosity measurement method. Before Symbol viscosity calculation process,
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 comprising a second calculation step of calculating the collision speed U of the droplet based on the maximum diameter D 0} measured in the second measurement step, the passing time ΔT, and the volume V calculated in the first calculation step. 4. The method for measuring the viscosity of a liquid according to 4. Before SL viscosity calculation step, the second measuring step the maximum diameter D ₀ is measured by _the third measuring maximum spread diameter is measured in step D _max, the first calculation step The calculated density ρ and the first 2. The method for measuring the viscosity of a liquid according to claim 5 , further comprising a third calculation step of calculating the viscosity μ of the liquid from the collision speed U calculated in the calculation step using the following formula (1).

(In equation (1), We is the Weber number, and A is the correction coefficient that changes depending on the wettability of the solid plane.)

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