JP2014001995A - Viscosity measuring method with stirring function, and apparatus for implementing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a viscosity measuring method augmented with a stirring function by which the number of revolutions and the running torque of a rotor are measured by monitoring the voltage of the motor used for stirring to measure the kinetic viscosity of a measurement object in a non-contact and opaque state, and an apparatus for implementing the method.SOLUTION: By a viscosity measuring method, a rotor with a built-in magnet is put into a container holding a measurement object, stirring is done by rotating the rotor with a rotating magnetic field, at the same time the running torque of the rotor is derived from the torque needed for generation of the rotating magnetic field, and the kinematic viscosity of the measurement object is figured out from the running torque needed for the number of revolutions set in an area in which the running torque and the kinematic viscosity are in a proportional relationship. By another method, the running torque of the rotor is derived in the same way as in the foregoing, and the kinematic viscosity of the measurement object is figured out from the number of revolutions of the rotor when the running torque set in an area in which the running torque and the kinematic viscosity are in an inversely proportional relationship is used.

Description

  The present invention relates to a viscosity measuring method with a stirring function and an apparatus therefor, and more specifically, using a metal container generally used as a high-pressure container, a rotor coupled by magnetic force is rotated at a low speed. Further, the present invention relates to a method and apparatus for measuring the kinematic viscosity of a measurement object in a non-contact and opaque state by measuring the rotation speed / rotation torque of the rotor by monitoring the voltage of the stirring motor.

  As a viscosity / elasticity measuring device, for example, a rotor and a detection target substance are placed, a container in which a rotor is arranged in the detection target substance, a container arranged around the container, and a magnetic field applied to the rotor. The magnet to be applied, the magnetic field is driven to change the magnetic field with time, an induced current is induced in the rotor, and the rotation is caused by Lorentz interaction between the induced current and the magnetic field applied to the rotor. A rotation control unit that applies rotation torque to the rotor to rotate, a rotation detection unit that detects the number of rotations of the rotor, and a viscosity detection unit that detects the viscosity and elasticity of the detection target substance that contacts the rotor based on the number of rotations. The apparatus which has is proposed (patent document 1).

  However, this apparatus is intended to measure absolute viscosity, not kinematic viscosity, and uses a sphere that cannot be expected to be stirred as a rotor. Also, the rotor is not a rotor with a built-in magnet but a conductive metal.

  Further, as an apparatus for determining the viscosity of the fluid, for example, an electric rotary drive including a stator having stator windings and a rotating body that can rotate in the fluid is included, and the rotating body serves as a rotor of the rotating drive. Designed, the rotating body is a non-contact magnetically supported device with respect to the stator, and the viscous power loss portion converted by the rotation of the rotating body in the fluid is the total power of the electric rotary drive. There has been proposed an apparatus including a means for operating a rotary drive in an operating range reaching at least 80% and a means for determining a viscosity (η) from a torque forming current (Iq) (Patent Document 2).

  However, this device is common to the present invention in that the rotor with a built-in magnet is rotated, but the purpose is to reduce mechanical friction, and the shape of the rotor and the driving method are different. According to Patent Document 2, it is obvious that a magnetic stirrer using a brush motor cannot perform practical viscosity measurement, and the present invention is not kept in mind.

  Further, as the stirrer and the stirrer, for example, a stirrer that stirs a liquid sample contained in a container by rotation, and the stirrer that can rotate horizontally and the magnetization direction of the stirrer There has been proposed a stirrer including a stirring magnet disposed on the stirring rotating body so as to be parallel to a rotation axis (Patent Document 3).

  However, this apparatus is a technique of the stirrer itself, and this document has no description about viscosity measurement.

  When measuring the viscosity of a liquid under high pressure, it is necessary to measure the viscosity in a high-pressure vessel. In addition, when the viscosity is measured after creating an equilibrium state in the high-pressure vessel, it is necessary to measure the viscosity in a high-pressure vessel having a stirring function. Even when focusing only on viscosity measurement, even if you try to make the viscometer with a rotating body attached to the tip of a shaft generally used under atmospheric pressure compatible with high pressure as it is, to put the tip of the shaft into a high pressure container, It is necessary to pressure seal in the middle of the shaft.

  O-rings, resin seals, and metal seals that are sealing materials change the tightening force on the shaft of the sealing material due to the pressure in the container, making it difficult to accurately measure the rotational torque of the rotating body from the rotational torque of the shaft It is.

  Further, when the rotation axis is used, the number of rotations can be accurately determined. However, when the rotation axis is not used, it is necessary to determine the number of rotations of the rotating body by some method. Although a method of marking the rotating body and optically determining it is conceivable, it cannot be used in a metal container without a window.

  In addition, until now, using a thick metal container generally used as a high-pressure container, the rotational speed and rotational torque of the rotor were measured by monitoring the voltage of the agitating motor. There has been no development example of a method and apparatus for measuring kinematic viscosity in the state, and there has been a strong expectation in the art to develop the apparatus.

JP 2009-264982 A Japanese Patent No. 4169542 JP 2007-1366443 A

  Under such circumstances, the present inventor has eagerly aimed at developing a method and apparatus that enables simple and efficient measurement of the viscosity of a liquid under high pressure in view of the above-described conventional technology. As a result of repeated research, a method and an apparatus for measuring the kinematic viscosity of a measurement object in a non-contact and opaque state by measuring the rotational speed and rotational torque of the rotor by monitoring the voltage of the stirring motor. Has been successfully developed, and the present invention has been completed.

  The present invention uses a metal container generally used as a high-pressure container, rotates a rotor coupled by magnetic force at a low speed, and determines the rotational speed and rotational torque of the rotor by the voltage of the stirring motor. It is an object of the present invention to provide a method and apparatus for measuring the kinematic viscosity of a measurement object in a non-contact and opaque state. Further, the present invention uses a rotor for stirring the solution, performs stirring by increasing the rotation speed of the rotor, and then measures kinematic viscosity by decreasing the rotation speed of the rotor. Therefore, it is an object to provide a means for performing simple and efficient measurement.

The present invention for solving the above-described problems comprises the following technical means.
(1) A rotor with a built-in magnet is placed in a container containing a measurement target, and the measurement target is stirred by rotating the rotor with a rotating magnetic field, and the rotational torque of the rotor is determined from the torque required to generate the rotating magnetic field. And measuring the kinematic viscosity of the object to be measured in the container from the rotational torque necessary for the number of revolutions set in a region where the rotational torque and the kinematic viscosity are in a proportional relationship.
(2) A rotor with a built-in magnet is placed in a container containing the object to be measured, and stirring is performed by rotating the rotor with a rotating magnetic field, and the rotating torque of the rotor is derived from the torque necessary for generating the rotating magnetic field. A method for measuring kinematic viscosity, comprising measuring the kinematic viscosity of a measurement object in a container from the number of rotations of a rotor when using a rotational torque set in a region where the number of rotations and kinematic viscosity are inversely proportional to each other .
(3) The method for measuring kinematic viscosity according to (1) or (2) above, wherein a magnetic stirrer stirrer is used as the rotor with a built-in magnet.
(4) The method for measuring kinematic viscosity according to any one of (1) to (3), wherein the rotor with a built-in magnet is cylindrical or elliptical.
(5) The method for measuring kinematic viscosity according to any one of (1) to (4), wherein the rotating magnetic field is generated by a mechanism that rotates a magnet by a motor.
(6) The kinematic viscosity measurement method according to any one of (1) to (5), wherein the rotating magnetic field is generated by a mechanism that rotates a magnet with a brush motor.
(7) The kinematic viscosity measurement method according to any one of (1) to (6), wherein the rotational torque of the rotor is derived by monitoring a voltage proportional to the motor torque.
(8) The method for measuring kinematic viscosity according to any one of (1) to (7), wherein the rotational speed of the rotor is derived by detecting the rotational speed of the motor.
(9) The kinematic viscosity measurement method according to any one of (1) to (8), wherein the rotational speed of the rotor is derived from a voltage change that is a torque change of the motor.
(10) The method for measuring kinematic viscosity according to any one of (1) to (9), wherein the number of rotations of the rotor is derived from a magnetic sensor installed near the container.
(11) A rotor with a built-in magnet, a measurement object, a high-pressure-resistant container in which the rotor is disposed, a magnetic field generating means for generating a rotating magnetic field in the rotor, and a rotational speed of the rotor are derived. And a detecting means for detecting the torque of the magnetic field generating means for generating the rotating magnetic field, and measuring the kinematic viscosity of the object to be measured by the method according to any one of (1) to (10). A kinematic viscosity measuring device.

Next, the present invention will be described in more detail.
The present invention relates to a method for measuring kinematic viscosity, in which a rotor with a built-in magnet is placed in a container containing the object to be measured, and the object to be measured is stirred by rotating the rotor with a rotating magnetic field, and a rotating magnetic field is generated. The torque of the rotor is derived from the torque required for the rotation, and the kinematic viscosity of the object to be measured in the container is measured from the rotation torque required for the rotation speed set in a region where the rotation torque and kinematic viscosity are in a proportional relationship. It is what.

  The present invention also relates to a method for measuring kinematic viscosity, in which a rotor with a built-in magnet is placed in a container containing a measurement object, and stirring is performed by rotating the rotor with a rotating magnetic field, and the rotating magnetic field is generated. The rotational torque of the rotating body is derived from the required torque, and the kinematic viscosity of the object to be measured in the container is calculated from the rotational speed of the rotating body when the rotational torque set in a region where the rotational speed and kinematic viscosity are inversely proportional It is characterized by measuring.

  The present invention is an apparatus for measuring kinematic viscosity, comprising a rotor with a built-in magnet, a measurement object, a high-pressure resistant container in which the rotor is disposed, and a magnetic field generating means for generating a rotating magnetic field in the rotor. A kinematic viscosity measuring device comprising a means for deriving the number of rotations of the rotor and a means for detecting the torque of the magnetic field generating means for generating the rotating magnetic field, wherein the rotor is rotated by the rotating magnetic field. As a result, the measurement object is agitated and the rotational torque of the rotor is derived from the torque necessary for generating the rotating magnetic field. From the rotational torque necessary for the rotational speed set in the region where the rotational torque and kinematic viscosity are proportional to each other. The kinematic viscosity of the object to be measured in the container is measured.

  The present invention is also a kinematic viscosity measuring device, comprising a magnet-containing rotating body, a measurement object, a high-pressure resistant container in which the rotor is disposed, and a magnetic field that generates a rotating magnetic field in the rotor. A measuring device for kinematic viscosity of a measuring object, comprising: a generating means; a means for deriving the number of rotations of the rotor; and a means for detecting the torque of the magnetic field generating means for generating a rotating magnetic field. While rotating the object to be measured, the rotational torque of the rotor was derived from the torque required to generate the rotating magnetic field, and the rotational torque set in the region where the rotational speed and kinematic viscosity were inversely proportional was used. The kinematic viscosity of the measuring object in the container is measured from the number of rotations of the rotor at the time.

  In the present invention, a magnetic stirrer stirrer is used as a rotor with a built-in magnet, the shape of the rotor with a built-in magnet is cylindrical or elliptical, and a rotating magnetic field is rotated by a motor. Generating is a preferred embodiment.

  In the present invention, the rotational torque of the rotor is derived by monitoring the voltage that is the torque of the motor, the rotational speed of the rotor is derived by detecting the rotational speed of the motor, and the rotational speed of the rotor. Is derived from a voltage change which is a torque change of the motor, and the rotational speed of the rotor is derived from a magnetic sensor installed near the container.

  As a configuration of the apparatus, preferably, for example, the control PC uses a Windows (registered trademark) XP-equipped personal computer, and the stirrer controller uses an ASONE M-1 multi-stirrer controller. In this case, after removing the 1 kΩ variable resistor of the stirrer controller, an Analog Devices AD8400 digital potentiometer is connected and connected so that the stirrer controller can be controlled from the PC.

  As the stirrer main body, for example, the ASONE S-1 stirrer main body is used, and a National Instruments USB-6609 data logger is connected to the line in the middle so that the voltage change of the line can be monitored by the PC.

  Examples of the pressure vessel are made of SUS316, and examples of the rotor include a Freon chemical strong stirrer oval type 25 mm, a strong stirrer oval type, and a strong stirrer cylinder type. The basic system can stir the measurement sample by using a commercially available magnetic stirrer, for example, by setting the rotational speed of the rotor to 300 rpm or more. These means can be used as appropriate as long as they have the same effect and are not limited to these means.

  When measuring the number of rotations of the rotor, for example, when a voltage change is measured with a data logger, periodic voltage fluctuations are observed, which is due to the rotation of the motor. Spike noise is periodically observed below and above, but this is noise that occurs every time the connection to the coil is switched because the brush motor is used in the used stirrer body.

  For example, in the case of this stirrer main body, the stirrer rotates once by the voltage fluctuation of six cycles of the motor. In addition, if the rotation of the rotor does not reach equilibrium because the stirrer does not rotate or goes wild, voltage fluctuations do not become periodic, so even if the rotor is not monitored directly, only the voltage monitor of the stirrer main unit can be used. It is possible to grasp the state in the container.

  When determining the rotational torque, the rotational torque of the rotor can be inferred from the torque of the motor of the stirrer body. The motor torque is proportional to the voltage applied to the motor, but in the case of a brush motor, spike noise interferes with the analysis. Therefore, after removing 20% before and after the spike noise, the remainder is approximated by a least square with a sine wave, and the center of the amplitude is analyzed as the motor torque.

  In this case, the analysis of motor torque takes into account the magnitude of spike noise depending on the type of power supply combined with the type of motor and the fluctuation of voltage due to torque, and the necessity and range of removal of spike noise and the function to be approximated. The shape settings need to be optimized. In the case of using the case of the ASONE S-1 stirrer body and ASONE M-1 multi-stirrer controller, the above-described method is effective. Then, a model is created in which the portion excluding the friction required for the rotation of the motor and the friction between the rotor and the bottom of the container is the torque that rotates the rotor in the solution.

  In the evaluation of the validity of the viscosity measuring apparatus, when a substance having a circular cross-sectional area moves through the solution, if the movement is slow, the viscosity force and the pressure gradient force are balanced. This relationship is derived from the case where the Reynolds number of the Navier-Stokes equation is small. This means that when the rotor is rotated slowly, the portion of the motor torque excluding the friction necessary for motor rotation and the friction between the rotor and the container bottom is proportional to the kinematic viscosity. .

  At this time, when the number of rotations is the same, the friction necessary for the rotation of the motor and the friction between the rotor and the container bottom are assumed to be constant (defined as reference torque).

The measured torque is defined by a linear function of c1 × kinematic viscosity of measurement sample + c2. Here, both c1 and c2 are constants caused by the apparatus, c1 is a relation between rotational torque and viscosity, and c2 is consumed by a reference torque (friction necessary for motor rotation, friction between the rotor and the bottom of the container) Torque). This is the sum of the torque required for the rotor to rotate in the viscous fluid (c1 × dynamic viscosity of the measurement sample) and the torque consumed in the measuring device (c2). It is shown that. The device constants c1 and c2 are
It can be determined by measuring two standard samples with different viscosities. Once the device constants c1 and c2 of the measuring device are determined, the kinematic viscosity can be derived from the measured sample by a simple formula of (measured torque−c2) ÷ c1.

  Appropriateness as an apparatus should satisfy whether this relationship is satisfied and whether a linear relationship between torque and kinematic viscosity is maintained in a state where a standard sample is used. For example, when the digital potentiometer AD8400 is used, the resolution is 256 steps and accurate control of the rotational speed is difficult. Therefore, the rotational torque and kinematic viscosity are obtained by linear interpolation based on data before and after the rotational speed is close. Get the voltage of the motor with respect to the rotation speed set in the area where is proportional.

  In actual measurement, for example, voltage measurement is performed with a 1 cSt calibration viscosity liquid and a 1000 cSt calibration viscosity liquid at a rotation speed of 180 rpm, and the linear relationship between the voltage and the kinematic viscosity is used to calculate the linear equation. After obtaining the device constant, the measurement sample is measured, and the kinematic viscosity of the measurement sample is derived from the measured voltage.

  In addition, when the motor or the rotor is moving, the dynamic friction coefficient is not affected by the speed of the moving object under an ideal environment. That is, when the torque to the motor is constant, the rotational speed of the rotating body and the motor torque are inversely proportional to the amount obtained by subtracting the reference torque from the motor torque, that is, the motor torque and the rotation cycle (the reciprocal of the rotational frequency). ) Is linear.

The present invention has the following effects.
1) Using a metal container generally used as a high-pressure container, the rotational speed and rotational torque of the rotor are measured by monitoring the voltage of the stirring motor, and the kinematic viscosity is measured in a non-contact and opaque state. And a device for the same can be provided.
2) Since the rotor is originally for stirring the solution, the stirring is performed by increasing the number of rotations of the rotor, and then the kinematic viscosity is measured by decreasing the number of rotations of the rotor. It is possible to provide a means for performing simple and efficient measurement.
3) Since the detector is on the stirrer side and the high-pressure vessel is merely mounted, it can be freely selected. It is possible to change the high-pressure vessel according to the sample, such as measuring an expensive sample with a small container and measuring an inexpensive sample with a large apparatus with increased accuracy.
4) Since a cylindrical high-pressure vessel having a certain diameter is used, cleaning after measurement is easy. This is optimal for measuring samples that are difficult to clean, such as paint.

The outline | summary of the apparatus of this invention is shown. An example of the voltage change measured by the data logger in the measurement of the number of rotations of the rotor is shown. An example of voltage change when the rotor rotation has not reached equilibrium after changing the stirrer controller setting is shown. An example of voltage change when the rotation of the motor of the stirrer body is too fast and the rotor stops rotating is shown. Measurement result 1 of dynamic viscosity (when an oval type 25 mm stirrer is used) is shown. The measurement result 2 of dynamic viscosity (when an oval type 20 mm stirrer is used) is shown. Measurement result 3 of dynamic viscosity (when a cylinder-type 20 mm stirrer is used) is shown. Measurement result 4 of dynamic viscosity (when an oval type 25 mm stirrer is used) is shown. Measurement result 1 is rewritten into a graph of rotation speed and voltage, and based on this graph, the rotation speed at a voltage of 0.9V is obtained, and the reciprocal with respect to time is taken to determine the rotation cycle for the kinematic viscosity at a motor voltage of 0.9V. It is the graph which calculated | required.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

(1) Device configuration of demonstration machine In this example, the following equipment was constructed as a demonstration machine. FIG. 1 shows an outline of the apparatus. The control PC was a Windows (registered trademark) XP-equipped personal computer, and the stirrer controller was an ASONE M-1 multi-stirrer controller. After removing the 1 kΩ variable resistor of the stirrer controller, an Analog Devices AD8400 digital potentiometer was connected so that the stirrer controller could be controlled from a PC.

  The stirrer main unit used the ASONE S-1 stirrer main unit, and a National Instruments USB-6609 data logger was connected to the line on the way so that the voltage change of the line could be monitored with a PC.

  The pressure vessel was made of SUS316, and verified using three types of rotors: a Freon chemical strong stir bar oval type 25 mm, a strong stir bar oval type 20 mm, and a strong stir bar cylinder type 20 mm. The basic system was found to be capable of stirring the measurement sample by using a commercially available magnetic stirrer and setting the rotational speed of the rotor to 300 rpm or higher.

(2) Measurement of rotation speed of rotor FIG. 2 shows an example of voltage change measured by a data logger.
From the figure, periodic voltage fluctuations are observed, which is due to the rotation of the motor. Moreover, spike noise was periodically observed below and above, but this was generated every time the connection to the coil was switched because the brush motor was used in the used stirrer body.

  In the case of this stirrer main body, it has been confirmed that the rotor makes one rotation with a voltage fluctuation of six cycles of the motor. Note that if the rotor does not rotate or goes wild and the rotation of the rotor has not reached equilibrium, the voltage fluctuation will not be periodic, so even if the rotor is not monitored directly, only the voltage monitor of the stirrer body is monitored. It was possible to grasp the state in the container (see FIGS. 3 to 4).

(3) Determination of rotational torque The rotational torque of the rotor was inferred from the torque of the motor of the stirrer body. The motor torque is proportional to the voltage applied to the motor, but in the case of a brush motor, spike noise interferes with the analysis. Therefore, after removing 20% before and after the spike noise, the rest was approximated by a sine wave to the least squares, and the center of the amplitude was analyzed as the motor torque. The motor torque analysis takes into account the magnitude of spike noise depending on the type of power source combined with the type of motor and the fluctuation of voltage due to torque, and the necessity and range of removal of spike noise and the form of the function to be approximated. It was necessary to optimize the setting.

  In the case of the ASONE S-1 stirrer body and ASONE M-1 multi-stirrer controller of this example, the above-described method was effective. Then, a model was created in which the portion excluding the friction required for the rotation of the motor and the friction between the rotor and the bottom of the container is the torque that rotates the rotor in the solution.

(4) Examination of the validity of the viscosity measuring device When a substance with a circular cross-sectional area moves through the solution, if the movement is slow (Reynolds number is sufficiently smaller than 1), the viscosity force and the pressure gradient force must be balanced. Is shown from the Navier-Stokes equations. This means that when the rotor is rotated slowly, the portion of the motor torque excluding the friction necessary for motor rotation and the friction between the rotor and the container bottom is proportional to the kinematic viscosity. .

  In the case of the same number of rotations, it is assumed that the friction necessary for the rotation of the motor and the friction between the rotor and the bottom of the container are constant (defined as reference torque), so the measured torque is c1 × measurement sample The linear function was defined as kinematic viscosity + c2. Here, both c1 and c2 are constants caused by the apparatus, c1 is a relation between rotational torque and viscosity, and c2 is consumed by a reference torque (friction necessary for motor rotation, friction between the rotor and the bottom of the container) Torque).

  The validity of the apparatus was evaluated by examining whether or not the torque and kinematic viscosity maintained a linear relationship in a state where this relationship was satisfied and a standard sample was used. Since the used digital potentiometer AD8400 has a resolution of 256 steps and it is difficult to accurately control the rotation speed, the voltage of the motor with respect to the specified rotation speed is obtained by linear interpolation based on data before and after the rotation speed is close. Acquired.

  In actual measurement, for example, voltage measurement is performed with a 1 cSt calibration viscosity liquid and a 1000 cSt calibration viscosity liquid at a rotation speed of 180 rpm, and the linear relationship between the voltage and the kinematic viscosity is used to calculate the linear equation. After obtaining the apparatus constant, the measurement sample was measured, and the kinematic viscosity of the measurement sample was derived from the measured voltage.

  In addition, when the motor or the rotor is moving, the dynamic friction coefficient is not affected by the speed of the moving object under an ideal environment. That is, when the torque to the motor is made constant, the rotational speed of the rotor and the motor torque are inversely proportional to the amount obtained by subtracting the reference torque from the motor torque. That is, the motor torque and the rotation cycle (reciprocal of the rotation frequency) were expected to be linear.

Measurement of dynamic viscosity 1 (when an oval type 25 mm rotor is used) [Example for claim 1]
FIG. 5 shows the measurement results. With the measurement sample having a viscosity of 1000 cSt, the rotor did not rotate at 420 rpm or higher, and the measurement was at 360 rpm or lower. It was found that the linearity of torque and viscosity was maintained in the measured range, and kinematic viscosity measurement was possible.

  Theoretically, it is assumed that the lower the number of rotations, the higher the accuracy. However, in the case of a motor-driven magnetic stirrer, the motor may stop at a lower number of rotations, so measurement at 180 rpm or higher is desirable. In addition, in the case of an oval (elliptical) rotor, the contact surface rotates with a very small surface at the center of the rotor so that the contact resistance with the container is small and the measurement variation is small. It was.

Measurement of dynamic viscosity 2 (when using an oval type 20 mm rotor) [Example for claim 1]
FIG. 6 shows the measurement results. It was possible to measure up to 600 rpm including a measurement sample having a viscosity of 1000 cSt, and high linearity was confirmed.

Measurement of dynamic viscosity 3 (when a cylinder type 20 mm rotor is used) [Example for claim 1]
FIG. 7 shows the measurement results. With the measurement sample having a viscosity of 1000 cSt, the rotor did not rotate at 480 rpm or higher, and the measurement was at 420 rpm or lower. In addition, a phenomenon in which the viscosity deviates from a straight line at 1000 cSt was observed at 240 rpm or higher.

  Since viscosity measurement needs to be measured in a linear region, it is suggested that measurement using a cylinder type 20 mm rotor needs to be measured at a low speed rotation of 180 rpm or less for a measurement sample having a viscosity of 1000 cSt or less. It was.

  In addition, when a cylinder type (cylindrical) rotor was used, the contact resistance with the bottom of the container was increased, so that the variation in measurement was larger than that of the oval type. It has been suggested that a rotor having a large central portion and a shape that comes into contact with the container only at the central portion is effective in improving measurement accuracy.

Measurement of dynamic viscosity 4 (when an oval type 25 mm rotor is used) [Example for claim 2]
FIG. 8 shows the measurement results. This graph is obtained by rewriting the measurement result 1 into a graph of rotation speed and voltage. Based on this graph, the number of rotations at a voltage of 0.9 V was obtained, the reciprocal with respect to time was taken, and the rotation period for the kinematic viscosity at a motor voltage of 0.9 V was obtained in the graph shown in FIG. is there.

  Thus, a linear relationship was obtained, and it was found that kinematic viscosity can be measured by measuring the rotation period at a determined motor voltage.

  As described above in detail, the present invention relates to a viscosity measuring method with stirring function and an apparatus thereof, and according to the present invention, using a metal container generally used as a high-pressure container, the rotational speed and rotational torque of a rotor. Can be measured by monitoring the voltage of the stirring motor, and a method and apparatus for measuring kinematic viscosity in a non-contact and opaque state can be provided. Since the rotor is originally for stirring the solution, the stirring is performed by increasing the rotational speed of the rotor, and then the kinematic viscosity is measured by decreasing the rotational speed of the rotor. A means for performing simple and efficient measurement can be provided.

Claims (11)

  The rotor with a built-in magnet is placed in a container containing the object to be measured, and the rotor is rotated by the rotating magnetic field to stir the object to be measured, and the rotational torque of the rotor is derived from the torque required to generate the rotating magnetic field. A method for measuring kinematic viscosity, comprising measuring a kinematic viscosity of a measurement object in a container from a rotation torque necessary for a rotation speed set in a region where the rotation torque and kinematic viscosity are in a proportional relationship.   The rotor with a built-in magnet is placed in a container containing the object to be measured, and stirring is performed by rotating the rotor with a rotating magnetic field. At the same time, the rotational torque of the rotor is derived from the torque required to generate the rotating magnetic field. And measuring the kinematic viscosity of the object to be measured in the container from the number of rotations of the rotor when the rotational torque set in a region where the kinematic viscosity is in an inversely proportional relationship is used.   The method for measuring kinematic viscosity according to claim 1 or 2, wherein a magnetic stirrer stirrer is used as the rotor with a built-in magnet.   The method for measuring kinematic viscosity according to any one of claims 1 to 3, wherein the rotor with a built-in magnet is cylindrical or elliptical.   The method for measuring kinematic viscosity according to claim 1, wherein the rotating magnetic field is generated by a mechanism that rotates a magnet by a motor.   The method for measuring kinematic viscosity according to claim 1, wherein the rotating magnetic field is generated by a mechanism that rotates a magnet by a brush motor.   The method for measuring kinematic viscosity according to claim 1, wherein the rotational torque of the rotor is derived by monitoring a voltage proportional to the torque of the motor.   The method for measuring kinematic viscosity according to claim 1, wherein the rotational speed of the rotor is derived by detecting the rotational speed of the motor.   The method for measuring kinematic viscosity according to any one of claims 1 to 8, wherein the rotational speed of the rotor is derived from a voltage change which is a torque change of the motor.   The method for measuring kinematic viscosity according to any one of claims 1 to 9, wherein the number of rotations of the rotor is derived from a magnetic sensor installed near the container.   A rotor with a built-in magnet, a measurement object, a high-pressure resistant container in which the rotor is disposed, a magnetic field generating means for generating a rotating magnetic field in the rotor, a means for deriving the rotational speed of the rotor, A kinematic viscosity of the measuring object, comprising a detecting means for detecting a torque of a magnetic field generating means for generating a rotating magnetic field, wherein the kinematic viscosity of the measurement object is measured by the method according to any one of claims 1 to 10. measuring device.