JP2525314B2 - Method and apparatus for measuring mixed fluid - Google Patents

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is used for controlling an emulsion which is a mixture of plural kinds of fluids which are insoluble in each other and a dispersion system which is a mixture of solid particles and a fluid. In particular, it relates to a technique for measuring and indicating the quality of emulsification and dispersion by the capacity ratio of two capacitors.

[0002]

2. Description of the Related Art Emulsions, which are mixtures of fluids that do not dissolve in each other, and dispersion systems, which are mixtures of solid particles and fluids, increase the non-uniformity when the components that are mixed are separated when left to stand.

Emulsions and dispersions include foods, cosmetics, adhesives,
It is widely used as a paint, etc., but if the separation of the compounding components fails to achieve the expected effect, the commercial value will drop significantly, so if an emulsion or dispersion system is manufactured as a product, it is not manufactured. It is necessary to confirm in advance that sufficient homogeneity is maintained during the period from the end to use.

When the separation of the blended components occurs, the heavy components sediment due to the difference in the specific gravity of each component, and the compositions of the upper layer and the lower layer differ. Therefore, by tracking the changes in the composition of the upper layer and the lower layer, Stability (a state where uniformity is maintained is called stability) can be evaluated.

Methods for tracking the change in composition include a method for directly examining the mixing ratio of components by chemical analysis and a method for detecting the change in composition from changes in physical properties. Methods for detecting changes in composition from changes in physical properties include mechanical methods, optical methods, and electrical methods.

[0006]

The chemical analysis lacks generality because the analysis method must be changed depending on the components contained. In addition, a sample must be taken in order to carry out a chemical analysis, but at this time it is extremely difficult to take the sample from the upper layer and the lower layer without flowing it at all. High stability is easily observed.

Among the methods of detecting from changes in physical properties, changes in viscosity are detected in mechanical methods, but it is almost impossible to measure the viscosities of the upper layer and the lower layer simultaneously and independently. As it must be, the effect of homogenization by flow appears as well as sampling in chemical analysis.

In the optical method, the transmittance or the spectrum of absorbed light is measured. However, since the transparency of the sample is often low, the detection sensitivity tends to decrease. Further, the influence of the transparency and absorption spectrum of the sample container is likely to appear, and it is necessary to take measures against this point.

In the electrical method, a method of measuring conductivity and capacitance can be considered, but conductivity can be applied only to a sample having an appropriate conductivity. Moreover, since the relationship between conductivity and composition cannot be easily determined, it is not very general. In addition, since there is a possibility that the separation of the components or conversely homogenization may be promoted by the influence of the voltage or current, a result different from the stability when left as it is may appear.

When measuring the capacitance, the above-mentioned drawbacks are less likely to appear, and it has been known that the capacitance is proportional to the dielectric constant of the substance existing between the electrodes. The advantage is that changes can be easily dealt with, but with the widely used impedance bridge measurement method, it is necessary to follow the zero point and the capacitance is not displayed directly, so continuous or automatic measurement is possible. Is not preferable.

The present invention has been made against such a background, and the stability of the emulsion and the dispersion system can be measured by using the electrostatic capacity, and the degree of the stability can be quantitatively expressed as a numerical value. An object is to provide a stability measurement display device.

[0012]

The first aspect of the present invention is to:
A mixed fluid measuring device, a container into which a test fluid is put, two pairs of electrodes provided so that the test fluid enters between electrodes at two different positions in the container, and this electrode An RC oscillator in which the capacitance (C1, C2) for each pair of (2) serves as a frequency determining element, and circuit means for obtaining the ratio of the capacitances (C1, C2) by the output signal frequency of the RC oscillator.

The two different positions are separated from each other in the direction of gravity, the electrodes are covered with an insulating film, and the two pairs of electrodes are made of printed wiring boards and have the same shape and the same interval. Is desirable.

A second aspect of the present invention is a method for measuring non-uniformity of a mixed fluid, in which counter electrodes are arranged at two positions where the dispersion state of a fluid to be measured is different, and each of the two counter electrodes is arranged. It is characterized in that the ratio (C1 / C2) of the interelectrode capacitances (C1, C2) is obtained and the nonuniformity of dispersion is obtained as a function of this ratio.

As an application of the present invention, the oscillator in which the capacitance (C1, C2) of each pair of the above-mentioned two pairs of electrodes serves as a frequency determining element is not necessarily RC oscillation, but the present invention can be implemented. That is, as an oscillator whose oscillation frequency is determined by the LC resonance circuit, an oscillator whose oscillation frequency is determined by the LCR resonance circuit, a crystal oscillator, and other mechanical vibration system additional capacitance,
It can also be implemented by an oscillator or the like to which the above-mentioned capacitors (C1, C2) are connected and whose oscillation frequency is fixed.

[0016]

The capacitance of the capacitor formed by the electrode plates immersed in the test fluid changes depending on the composition of the test fluid filled between the electrode plates.

The capacitors are provided on the upper and lower parts of the container in which the fluid to be tested is stored, and the capacitance of each is measured. As a measuring method, for example, it is desirable to configure an RC oscillator in which this capacitor is C and measure a change in its oscillation frequency. That is, the oscillation frequency ratio of the two RC oscillators is proportional to the capacitance ratio of the two capacitors. Therefore, stability is expressed as a function of the capacitance ratio of the two capacitors.

The uniformity of the fluid to be measured is measured by the capacitance ratio of the capacitors provided on the upper and lower portions, and the value is displayed on the display.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a first embodiment device of the present invention.

According to the present invention, a container 10 which is a container into which a fluid to be measured is put, and two different positions in the container 10 are provided so that the fluid to be measured may enter between electrodes.
Capacitors C1 and C2, which are paired electrodes, and R, which is the capacitance of the capacitors C1 and C2, are frequency determining factors.
Timer ICs 1 and 2 which are C oscillators, and this timer I
A device for measuring a mixed fluid, comprising circuit means for determining a ratio of capacitances of capacitors C1 and C2 based on output signal frequencies of C1 and 2.

The two different positions are positions separated from each other in the direction of gravity, and the electrodes constituting the capacitors C1 and C2 are laminated layers or printed wiring boards in which at least one of the electrodes is covered with an insulating film. Have the same shape and the same interval.

In the apparatus of the first embodiment of the present invention, capacitors C1 and C2, which are counter electrodes, are arranged at two positions where the dispersion state of the emulsion to be tested is different, and the ratio of the respective capacities of the two capacitors C1 and C2. And the non-uniformity of the dispersion as a function of this ratio.

Timer ICs 1 and 2 (both NE55
5) is used, the oscillation frequency thereof is determined by the resistance values of the resistors R1 to R4 and the capacitances of the capacitors C1 and C2. If the resistors R1 and R3 have the same resistance and the resistors R2 and R4 have the same resistance, the timers IC1 and IC2 oscillate at the same frequency when the capacitors C1 and C2 have the same capacitance. In the device of the first embodiment of the present invention, since the capacitance ratio of the capacitors C1 and C2 is taken out as the oscillation frequency ratio of the timer ICs 1 and 2, the resistance values of the resistor R1 and the resistor R3, and the resistor R2.
And the resistance values of the resistor R4 are set to be equal to each other. In the device of the first embodiment of the present invention, the resistor R1 and the resistor R
The resistance value of 3 was 5 KΩ, and the resistance values of the resistors R2 and R4 were 10 KΩ. At this time, the capacitors C1 and C2 each have a capacitance of about 10
If it is 00 pF, the oscillation frequencies of the timer ICs 1 and 2 are about 20 KHz.

The structure of the capacitors C1 and C2 in the first embodiment device of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing a printed wiring board that constitutes capacitors C1 and C2 of the device of the first embodiment of the present invention. FIG. 3 is a view showing the installation state of the capacitors of the device of the first embodiment of the present invention. As a material of the substrate, glass epoxy is used, as shown in FIG. 2 (a), a printed wiring board provided with a pattern to be the common electrode C, and as shown in FIGS. 2 (b) and 2 (c), Capacitors C1 and C2 are formed by a printed wiring board provided with a pattern to be electrodes C1 'and C2'.

As shown in FIG. 3, in the longitudinal direction of the container 10,
The printed wiring board having the pattern of the common electrode C of FIG. 2A on both sides and the pattern of FIG.
FIG. 3 shows a printed wiring board having the pattern of (c) on the back surface.
As shown in FIG. By stacking, the total capacity of each is obtained as the output. In the printed wiring board provided with the common electrodes C on both ends, the common electrode C was provided only on one surface on the inner side.

When the fluid to be measured contains a large amount of water and the electric conductivity is high, the tan δ of the capacitors C1 and C2 may become large, and the oscillation waveform and phase may change. In such a case, This was dealt with by applying an insulating coating to the electrode plate. In the device of the first embodiment of the present invention, a PT having a thickness of 20 μm is used.
When tan δ coated with FE and immersed in water to measure tan δ, tan δ was 10% or more without coating, but was 0.01% or less.

The electrode plate is used by immersing it in the test fluid.
At this time, if the position of the upper or lower electrode plate is such that it crosses the boundary surface 12 when layer separation occurs, the difference in electrostatic capacitance between the upper and lower portions is reduced and the detection sensitivity is reduced. Therefore, when increasing the area of the electrode plate, the left and right lengths are increased as shown in FIG. 3 rather than the upper and lower lengths. Further, the upper and lower electrode plates must be sufficiently separated from the boundary surface 12 when separated.

The stability of an emulsion containing water and liquid paraffin was measured using the apparatus of the first embodiment of the present invention. When the emulsification is complete, there is no difference in the composition of the upper and lower layers, so that the capacitances of the upper and lower electrodes are equal, and as a result, the timer I
Oscillation frequencies of C1 and 2 are equal, and the frequency ratio is "1"
Becomes This frequency is determined by the composition of the fluid to be tested between the upper and lower electrode plates, but if the composition is constant, the frequency ratio is always "1" regardless of the dielectric constant of each component, and the demulsification progresses. When the water layer and the oil layer are completely separated, the dielectric constant of water is about 78 and that of liquid paraffin is about 2.2.
Therefore, the frequency ratio is about 35.

In the case of a suspension containing a powder heavier than water, the frequency ratio is still "1" unless there is a difference in the composition of the upper layer and the lower layer, but when the particles aggregate and settle, the capacitance of the lower electrode Is decreased and the capacitance of the upper electrode is increased, so that the frequency ratio is smaller than “1” when the frequency of the oscillator connected to the upper electrode is used as a reference as in the case of the emulsion. If this happens, use capacitors C1 and C
If the connection of 2 is reversed, the frequency ratio will increase with the elapse of time, with the value "1" at the time of perfect uniformity being the minimum value.

As described above, since the frequency ratio is a dimensionless quantity corresponding to the nonuniformity of the fluid to be measured, the degree of nonuniformity is U.
If f, this value is represented by Uf = 1 + f (t) (1). However, f (t) is a function of time.

In the past, it was difficult to express the degree of uniformity or nonuniformity as a numerical value, so it was difficult to quantitatively standardize the stability, but if Uf is used, the uniformity (nonuniformity) The degree of (uniformity) can be quantitatively expressed as a numerical value. In addition, by applying a mathematical method (for example, regression analysis method) from the experimental result in a relatively short period (hours or days), f
By obtaining the concrete functional form of (t) and the coefficient of the regression equation, it is possible to predict the stability (uniformity) over a long period (months to years) by calculation.
Further, the control limit value of Uf can be easily determined by measuring the Uf of the sample in which separation actually occurs, and the time to reach the limit value can be calculated from the equation (1).

To measure the value of Uf, the output frequencies of the timer ICs 1 and 2 are set to the two frequency counters 3 and 4.
, And divide the higher frequency by the lower frequency.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram of a second embodiment device of the present invention. In the first embodiment of the present invention, in order to measure the value of Uf, the output frequencies of the timer ICs 1 and 2 are displayed on the two frequency counters 3 and 4, and the higher frequency is divided by the lower frequency. It was found that it is quite difficult to read the displays of the two frequency counters 3 and 4 at the same time with respect to the emulsion to be tested, which has poor stability and drastically changes in frequency. Therefore, in the second embodiment of the present invention, the lower frequency signal is used as a generation source of the gate pulse, the reset pulse and the latch pulse of the frequency counter 5, so that the value of Uf is directly displayed on one frequency counter 5. It is characterized by doing. However, when the frequency ratio is close to “1”, counting or latching may not be performed properly depending on the timing of each pulse, and the value of Uf, which should not be originally “1” or less, may be “0”. . In order to prevent such a miscount and improve the reading accuracy of the value of Uf, the signal of the output 2 is divided by the 1/200 frequency divider circuit 6 and then connected to each input of the frequency counter 5. . The latch input in the device of the first embodiment of the present invention is
The frequency counter 5 is configured to be used by being delayed by a delay circuit (not shown) inside the frequency counter 5 so that the output of the frequency counter 5 is stabilized before latching. In this case, if the frequencies of the output 1 and the output 2 are equal, the frequency counter 5 displays "100" instead of "1", but lights the decimal point to display "1.00".

Next, the device of the third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing the configuration of the third embodiment device of the present invention. The device of the third embodiment of the present invention is obtained by removing the NAND gate 8 from the device of the second embodiment of the present invention, and is configured with a small number of parts. However, unlike the device of the second embodiment of the present invention, Since the counter output is latched, the display becomes unstable. However, when a display is read by a human, this unstable display rarely occurs and is not recognized by the human eye, so that it does not pose a practical problem.

Next, the operation of the apparatus according to the third embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. FIG. 6 is a time chart showing the operation of the third embodiment device of the present invention. In the device of the third embodiment of the present invention, the output 1 is waveform-shaped by the inverter 7 and then connected to the count input of the frequency counter 5. The output 2 is subjected to waveform shaping similarly to the output 1 and then divided by the frequency dividing circuit 6, and the JK flip-flop 9 outputs a reset pulse and a latch pulse to 1 every two cycles of the divided output as shown in FIG. It is generated at a timing shifted from the cycle.

Output 1 is constant at 15 KHz and output 2 is 4
FIG. 6 shows a timing chart in the case of changing from KHz to 6 KHz.

When the reset pulse is generated, the count value of the frequency counter 5 is cleared to "0". After that, the count value of the frequency counter 5 is counted by the output 1 and rises from "0". Although the output 2 is divided by 100, a latch pulse is generated when the time t1 of one cycle elapses, and the count value at that time is latched and displayed.
When output 2 is 4 KHz, t1 is 25 msec and output 1 is 15 KHz, so the count value is "37.
Rise to 5 ". A decimal point lights up on the display device (not shown) as in the second embodiment device of the present invention.
5 ”is displayed.

When the output 2 changes to 6 KHz, the period t2
Is 100/6 msec, and the count value increases until it is latched is "250", so the display is "2.5.
Changes to 0 ".

As described above, since the time from the reset pulse to the latch pulse changes according to the frequency of the output 2, the change in the frequency ratio can be displayed.

When the frequency of the output 1 changes, the count value of the counter that rises in the time from the reset pulse to the latch pulse increases or decreases according to the change, so that the change in the frequency ratio can be displayed.

As described above, by using the second and third embodiments of the present invention, it is possible to easily measure the change in the ratio of the frequencies of the output 1 and the output 2.

[0042]

As described above, according to the present invention, the stability of the emulsion and the dispersion system can be measured by using the capacitance, and the degree of the stability can be quantitatively expressed as a numerical value.

This device is useful as a device for inspecting cosmetics, adhesives, paints, foods, and other manufacturing processes, and for determining the quality of stored products.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a capacitor of the first embodiment device of the present invention.

FIG. 3 is a diagram showing an installation state of capacitors of the first embodiment device of the present invention.

FIG. 4 is a block diagram of a second embodiment device of the present invention.

FIG. 5 is a flowchart showing the operation of the second embodiment device of the present invention.

FIG. 6 is a time chart showing the operation of the device of the third embodiment of the present invention.

[Explanation of symbols]

 1, 2 Timer ICs 3, 4, 5 Frequency counter 6 Dividing circuit 7 Inverter 8 NAND gate 9 JK flip-flop 10 Container 12 Boundary surface A to L pulse C Common electrode C1 ', C2' electrodes C1 to C4 Capacitors R1 to R4 Resistor

Claims (6)

(57) [Claims] 1. Two pairs of electrodes provided at two different positions so that the fluid to be measured penetrates between the electrodes, and the capacitance (C1, C2) of each pair of the electrodes serves as a frequency determining element. Depending on the RC oscillator and the output signal frequency of this RC oscillator, the capacitance (C
And a circuit means for determining the ratio of C2). 2. The mixed fluid measuring device according to claim 1, wherein the two different positions are positions spaced apart in the direction of gravity. 3. The mixed fluid measuring device according to claim 1, wherein the electrode is covered with an insulating film. 4. The mixed fluid measuring device according to claim 1, wherein the two pairs of electrodes are respectively formed of a printed wiring board and have the same shape and the same interval. 5. A counter electrode is arranged at each of two positions where the dispersion state of the test fluid is different, and the ratio (C1 / C2) of the interelectrode capacitances (C1, C2) of these two counter electrodes is calculated to obtain the dispersion. A method for measuring a mixed fluid, characterized in that the non-uniformity of is calculated as a function of this ratio. 6. An oscillator in which two pairs of electrodes are provided at two different positions so that the fluid to be measured enters between the electrodes, and the capacitance (C1, C2) of each pair of the electrodes serves as a frequency determining element. And the capacitance (C1, C
An apparatus for measuring a mixed fluid, comprising a means for obtaining the ratio of 2).