JPH0712705A - Method and device for measuring viscosity of viscous fluid - Google Patents

Abstract

PURPOSE:To measure the viscosity of a viscous fluid accurately and rapidly. CONSTITUTION:A dropping body 9 dropping through a viscous fluid 3 in a transparent constant temperature oven 2 and a graduation on a graduated plate located along its path are focused separately by an image sensing camera 4, and the image is obtained as an image data by an image processing means 5. While the image data is being outputted on a monitoring TV 7, a start switch 16 is pressed when the dropping body 9 passes a proper position on the screen of the monitoring TV 7 to start measuring the time for a preset length. Then the positions of the dropping body 9 at the times when the time was started to measure and the measurement was completed are calculated by a host computer 6 to calculate the dropped distance in the viscous fluid 3 and obtain its viscosity from a specified theoretical equation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the viscosity of a viscous fluid such as silicone oil and a viscosity measuring device.

[0002]

2. Description of the Related Art Among various conventionally well-known viscosity measuring methods, the viscosity measuring method using a falling ball viscometer is stipulated in Japanese Industrial Standard (JIS) Z8803 regarding a standard method and dimensions of measuring instruments. ing. According to this method, as shown in FIG. 5, a transparent sample container 101 having a cylindrical shape with a bottom is arranged in a transparent transparent container 100, and the viscosity should be measured in the sample container 101. Detected viscous fluid 1
02 is inserted up to a predetermined height, and an introducing cylinder 104 for freely dropping the falling body 103 such as a ball-bearing steel ball or glass ball is arranged at the upper end thereof. Reference numeral 105 is a liquid medium for keeping the temperature constant, reference numeral 106 is a thermometer, reference numeral 107 is a stirrer for agitating the liquid medium 105, and an air escape hole 108 is formed on the side surface of the introduction cylinder 104. Has been done.

The sample storage cylinder 101 has an inner diameter equal to or more than five times the diameter of the falling body 103 and is uniform, and the interval between the upper marked line 109 and the lower marked line 110 for measuring the time required for the falling body 103 to fall is 50 mm or more, and the lower marked line 110 needs to be 50 mm or more from the bottom of the sample storage cylinder 101.
The liquid surface of the viscous fluid 102 to be detected, which is a sample, has an upper marked line 10
There are regulations such as putting it so that it is located 50 mm or more above 9.

Then, the falling body 10 is introduced from the introducing cylinder 104.
3 is put in, and the required time T from the moment when the falling body 103 passes the upper marking line 109 to the moment when it passes the lower marking line 110 is measured. The measurement time T is measured three times or more, and the average value thereof is substituted into the following theoretical formula (A) to obtain the viscosity η of the viscous fluid 102 to be detected. η = f × 100d ² (ρo-ρ) gT / 18L ・ ・ ・ (A) where η: viscosity (mPa ・ s) d: diameter of falling body (sphere) (cm) ρo: density of sphere (g / cm ³ ) ρ: Density of viscous fluid to be detected (g / cm ³ ) g: Gravity acceleration (cm / g ² ) T: Fall time between time reference lines (s) L: Distance between time measurement lines (cm) D: Inner diameter of sample storage cylinder (cm) f: Correction coefficient for the influence of the liquid tank wall surface, which is a constant value when the diameter of the sphere and the inner diameter of the sample storage cylinder are determined. f = 1-2.104 (d / D) +2.09 (d / D) ³ -0.95 (d / D) ⁵

[0005]

However, this measuring method has the following drawbacks. That is, the measurer depends on the manual work of pressing the start button of the stopwatch at the moment when the falling body 103 passes the upper marking line 109, and pressing the stop button at the moment when the falling body 103 passes the lower marking line 110. Since it measures the time required for falling, it is said that the resolution with which the measurer can visually recognize the passage of the sphere through the upper marked line 109 and the lower marked line 110 with the naked eye is about 0.1 mm. By the reflexes of the person from visual recognition to button press,
Since an error of 0.1 second, which is the minimum reading unit defined by JIS, cannot be avoided, the measurement error will be large.

In order to reduce this error, if the viscosity measurement result is obtained from the average value of a large number of measurement results, the optic nerve of the measurer becomes tired, and the error tends to increase. In addition, the measurement result varies depending on the individual difference of the measurer. Furthermore, since the time required for the sphere to pass the predetermined distance from the upper marked line 109 to the lower marked line 110 is visually measured, it is not possible to shorten the measuring time, and the viscosity can be measured quickly as a whole. Moreover, there is a drawback that it cannot be performed accurately.

It is an object of the present invention to solve the conventional problems and provide a method for measuring the viscosity of a viscous fluid quickly and accurately and a measuring device suitable for the method.

[0008]

In order to achieve the above object, the viscous fluid measuring method of the present invention comprises a scale plate arranged in advance along a drop passage of a falling body that drops in the viscous fluid in a transparent container. Scale data obtained by imaging and recognition image data of the falling body are stored in advance, and then, regarding a falling body that drops in the viscous fluid to be detected in the same transparent container as described above, at any detection start time point. The position of the falling body and the position of the falling body when a predetermined time length has elapsed from that time are respectively detected, and the fall distance of the falling body for the predetermined time length is calculated from the comparison of the detected value and the scale data, Then, the viscosity of the viscous fluid to be detected is determined from the calculated value and a predetermined theoretical formula.

As the viscosity measuring device, a transparent container containing a viscous fluid whose viscosity is to be measured, and a scale plate for arranging the viscous fluid in the transparent container along the path of a falling body that falls. An image pickup camera for respectively picking up the scale of the scale plate and the falling body from the outside of the transparent container, image processing means for obtaining predetermined image data, monitor means for outputting the image data, and the falling body in the monitor means. It is provided with a start switch for starting time measurement when passing an appropriate position on the screen, a data storage means, and a central processing unit for executing a predetermined calculation from the obtained data.

[0010]

EXAMPLE Next, an example in which the present invention is embodied will be described. FIG. 1 shows a block diagram of a measuring apparatus 1 for carrying out the viscosity measuring method of the present invention, and reference numeral 2 should measure viscosity. A thermostatic chamber which is an example of a transparent container containing the viscous fluid 3, reference numeral 4 is an image pickup camera such as a CCD camera (camera using a two-dimensional solid-state image pickup device), and reference numeral 5 is image processing means for processing the captured image. In addition, it has an image dedicated memory (a memory (RAM) capable of being read and written at any time), and an image processing program (software) is supported by a ROM processor. In the image processing means 5, according to commands from the host computer (personal computer) 6, image input / output, image arithmetic operations, logical operations, character display, cursor operation, image gradation conversion (gradation compression or negative Functions such as positive inversion) and various basic image processing (Laplacian, difference, etc.) are provided.

As will be described later, in the host computer 6, the start switch 16 is pressed to activate the counting of a predetermined time length T, the coordinates of the falling body 9 at the measurement start time and when the predetermined time length T elapses. Is stored, a control program for executing the calculation of the fall distance L, the calculation of the theoretical formula (A) for obtaining the viscosity is stored, and a predetermined constant (fall The density of the body 9 and the viscous fluid 3 to be measured, the set time length T, the diameter of the constant temperature chamber 2 and the falling body 9, and the like) are input in advance from the keyboard 17.

Reference numeral 7 is a monitor television, and reference numeral 8 is a constant temperature bath 2.
It is a light source necessary when the imaging camera 4 captures images of the falling body 9 such as a steel ball and the scale of the scale plate 10. In the embodiment, a fluorescent lamp and a diffusion plate for preventing uneven illumination and abnormal reflection are used. Consists of. In order to keep the temperature of the viscous fluid 3 in the constant temperature bath 2 constant, a temperature control device 13 connecting a heater 11 and a thermometer 12 is connected to the host computer 6. Reference numeral 14 is an output device such as a printer for recording the measurement result data.

Next, the measuring method of the present invention using the measuring device 1 will be described. First, as a preparatory step for measuring the position of the falling body 9 on the image data, the coordinates of the falling distance, and the like, after placing a predetermined viscous fluid 3 in the constant temperature bath 2, the spherical falling body 9 is measured when the viscosity is measured. A scale plate 10 as a calibration ruler is erected in the thermostatic chamber 2 so that the center line of the sphere when falling falls in line with the vertical plane (see FIG. 2).

Then, the position of the image pickup camera 4 is fixed, and the horizontal distance H between the reference position of the image pickup camera 4 (the surface of the optical lens, the surface position of the solid-state image pickup device, the focus position, etc.) and the surface of the scale plate 10. With a constant state, the image of the scale of the scale plate 10 is image-processed by the image processing means 5, whereby the relationship between the coordinates on the screen of the monitor TV 7 and the scale (absolute position) is stored in the host computer 6. It is stored in the storage means (RAM). In this case, the image of the scale line and the background generally has a clear black-and-white contrast, so that a binarized image can be easily obtained.

In the height position of the image pickup camera 4 and the distance H, there is no difference in the interval between the upper and lower scales on the scale plate 10 due to the aberration of the optical system within the image pickup range (the range where an image can be obtained). On (so that there is no distortion of the scale)
If the setting is made, the subsequent coordinate calculation becomes easy. However, if it is difficult or very time-consuming, it is possible to make the correction in the calculation processing step.

Next, the falling body 9 at the same horizontal distance H as described above is photographed by the image pickup camera 4, and the image is subjected to image processing by the image processing means 5 to obtain data for pattern matching of the falling body 9. Then, the position (coordinates) of the subsequent falling body 9 is determined by calculating the position of its center of gravity from the image data of the falling body 9. Next, the operation of viscosity measurement is performed. Before that, assuming a time length required for the falling body 9 falling in the viscous fluid 3 to drop by a predetermined fall distance, the value of the necessary time length T is input in advance to the host computer 6. Keep it. In this case, the drop distance according to the JIS (Z8803 standard) is 50 mm or more, but the method of the present invention has a measurement accuracy of about 10 times that of the viscosity measuring method according to the JIS standard described above. Since it was found that the accuracy required by JIS can be secured even if the drop distance is reduced to about 5 mm, in the case of the method of the present invention, when the drop distance is about 5 to 10 mm, The time required for measurement can be shortened by inputting the time length T required for the falling body to fall by the fall distance into the host computer 6. Next, in the thermostatic chamber 2 from which the scale plate has been removed, The viscous fluid 3 whose viscosity is to be measured is put in and maintained at a predetermined temperature, and the lower end of the introducing cylinder 15 is dipped in the liquid surface of this viscous fluid 3 to stand vertically, whereby along the inside of the introducing cylinder 15. Dropped The spherical falling body 9 prevents the disturbance such as the surface of the viscous fluid 3 from wavy, etc. The introduction cylinder 15 is erected at the same position as the scale plate 10 is erected. The horizontal distance from 4 is H.

Next, with the image pickup camera 4 turned on,
When the falling body 9 is allowed to fall freely from the introduction tube 15 and the image 9a of the falling body 9 comes to an appropriate position on the screen (a portion near the upper portion is preferable) while monitoring the screen of the monitor TV 7.
Press the start switch 16. As a result, the host computer 6 automatically starts counting the time length T to be measured.

In this case, the image 9a of the falling body 9 which is being photographed by the image pickup camera 4 is compared with the data of the reference pattern that was previously photographed, and the position (coordinates) of the falling body 9 is obtained by pattern matching. Is always identifiable, the coordinates (0, Y) at the time when the fall distance measurement of the falling body 9 is started at the same time when the start switch 16 is pressed.
1) (the vertical position in this case) will be specified. Next, since the coordinates (0, Y2) of the image 9a of the falling body 9 at the time when the time length T has elapsed (at the time when the measurement ends) are controlled so as to be automatically measured (specified), the scale plate 10 The fall distance L = Y2−Y1 as an absolute value is obtained by the calculation of the host computer 6 by comparison with the scale data in (1) (see FIG. 4). Since the fall distance L which is the measured value is equal to the distance between the time reference lines in the theoretical formula (A), the fall distance L and the time length T to be measured are used in the theoretical formula (A). The viscosity η can be obtained by substituting and computing by the host computer 6.

Since the coordinates of the falling body 9 are specified only twice when the fall distance measurement starts and when the time length T elapses, the image captured by the image capturing camera 4 is selected. Freeze (f
Since it is sufficient to perform the pattern matching processing by extracting the data, the image processing time may take a little longer.

The measurement device 1 having the same specifications (shape and dimensions) was used, and an experiment was conducted on a reference (standard) viscous fluid whose viscosity was previously determined, and the device constant K = 100d ² g
If f / 18 is obtained, η = K instead of theoretical formula (A)
It suffices to execute the calculation of (ρo−ρ) T / L, and the viscosity η can be easily obtained.

[0021]

In summary, according to the measuring method of the present invention, it is possible to obtain the image beforehand of the scale plate arranged along the drop passage of the falling body that drops in the viscous fluid to be detected in the transparent container. Scale data and the recognition image data of the falling body are stored in advance. As a result, the position of the subsequent falling body can be specified and the absolute value of the falling distance can be obtained.

Next, regarding the falling body that drops in the viscous fluid to be detected in the same transparent container as described above, the position of the falling body at the arbitrary detection start point and the position of the falling body when a predetermined time has elapsed from that point Respectively, calculate the fall distance of the falling body for a predetermined time length from the comparison between the detected value and the scale data, and then calculate the viscosity of the viscous fluid to be detected from the calculated value and a predetermined theoretical formula. decide.

With this arrangement, the position of the falling body at the time of starting the detection and the drop after a lapse of a predetermined time only need to be specified for the falling body on which the viscous fluid to be detected is falling. Both positions of the body can be specified, and the fall distance of the falling body can be measured. Therefore, since the measurer determines only the detection start time when measuring, the cause of the measurement error is reduced, and the accuracy of viscosity measurement is improved, and the measurement work can be performed quickly.

The viscous fluid viscosity measuring device includes a transparent container containing a viscous fluid whose viscosity is to be measured and a scale for arranging the viscous fluid in the transparent container along the path of a falling body. A plate, an imaging camera for respectively imaging the scale of the scale plate and the falling body from outside the transparent container, and an image processing means for obtaining predetermined image data,
Monitor means for outputting image data, a start switch for starting time measurement when a falling object passes an appropriate position on the screen of the monitor means, a data storage means, and a predetermined calculation is performed from the obtained data. Since it is provided with a central processing unit for doing so, the time length to be measured is input and stored as data in advance, and while watching the image of the falling body output to the monitor means at the time of the viscosity measurement, When you pass the appropriate position on the screen, you can start the time measurement simply by operating the start switch.
The position of the falling body at that time and the position of the falling body when the predetermined time length stored in the central processing unit has elapsed can be detected by comparing the scale data with the specific data of the falling body itself. . Further, since the fall distance over which the falling body drops the viscous fluid to be detected can be automatically measured during the predetermined time period, and the calculation of the theoretical formula can be performed at high speed by the central processing unit, the viscosity can be calculated quickly and accurately. The effect is that the viscosity of the fluid can be measured.

[Brief description of drawings]

FIG. 1 is a block diagram of a viscosity measuring device of the present invention.

FIG. 2 is an explanatory diagram showing a state in which a scale of a scale plate is photographed.

FIG. 3 is an explanatory view showing a state in which a falling body in a viscous fluid to be detected is photographed.

FIG. 4 is a diagram showing a screen of a monitor television.

FIG. 5 is a diagram showing a conventional measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring device 2 Constant temperature bath 3 Viscous fluid 4 Imaging camera 5 Image processing means 6 Host computer 7 Monitor TV 9 Falling body 10 Scale plate 15 Introduction tube 16 Start switch 17 Keyboard

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seisei Wang 883 Kamikitajima, Chikugo City, Fukuoka Prefecture Apollo Electronics Co., Ltd.

Claims (2)

[Claims] 1. Scale data obtained by previously capturing an image of a scale plate arranged along a drop passage of a falling body that falls in a viscous fluid in a transparent container, and recognition image data of the falling body are stored in advance. Then, regarding the falling body falling in the viscous fluid to be detected in the same transparent container as described above, the position of the falling body at the arbitrary detection start time and the position of the falling body when a predetermined time has elapsed from that time Detecting each, calculate the fall distance of the falling body for a predetermined time length by comparing the detected value with the scale data, and then determine the viscosity of the viscous fluid to be detected from the calculated value and a predetermined theoretical formula. A method for measuring the viscosity of a viscous fluid, comprising: 2. A transparent container containing a viscous fluid whose viscosity is to be measured, a scale plate for arranging the viscous fluid in the transparent container along a path of a falling body that falls in the viscous fluid, and a scale of the scale plate and An imaging camera for respectively capturing the falling body from outside the transparent container, an image processing means for obtaining predetermined image data, a monitor means for outputting the image data, and the falling body passing through an appropriate position on the screen of the monitor means. and when,
A viscosity measuring device for viscous fluid, comprising: a start switch for starting time measurement; a data storage means; and a central processing unit for executing a predetermined calculation from the obtained data.