JP3579706B2 - Capacitive material measuring device and material measuring method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a capacitance-type substance measuring device and a substance measuring method for measuring electric characteristics of a substance caused by a tissue state of a substance mass.
[0002]
[Prior art]
Some substances have their electrical properties determined by their tissue state. For example, it is a foamable synthetic resin pumice in the field of daily necessities.
In this type of pumice, porous bubbles are formed during the manufacturing process, but the texture when shaving off the keratinized skin is different depending on the state of the bubbles, so it is manufactured while controlling to obtain a constant bubble state. There is a need.
[0003]
Conventionally, in order to inspect the bubble state of this kind of porous substance, it has been common practice to take a sample from the production line and perform it based on human senses such as a tester's feeling and visual observation.
[0004]
[Problems to be solved by the invention]
However, when examining the above-mentioned porous material, etc., in the sense and visual observation by the tester, the test condition to be evaluated, the gender, age, the reference value is likely to be separated or varied by various other factors, it is easy to occur, It was difficult to perform quantitatively and accurately.
[0005]
The present inventor has earnestly observed and studied the tissue state formed in such a substance, for example, its bubble state, outer shape, and electrical properties (impedance value). As a result, the electrical properties change depending on the tissue state of the substance. The present invention was completed by focusing on the fact that it can be shown by certain electrical characteristics.
[0006]
The present invention has been made under such circumstances, and a substance whose electrical characteristics are determined by a tissue state and an outer shape formed in the substance, without the tester's feelings or visual observation, is not required It is an object of the present invention to provide a capacitance-type substance measuring device and a substance measuring method capable of electrically and quantitatively measuring a characteristic from outside a substance.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, a first invention according to the present application provides a band-shaped auxiliary electrode to which a predetermined oscillation signal is applied, and a band-shaped auxiliary electrode which is disposed to face the auxiliary electrode and which has an impedance between the auxiliary electrode and the auxiliary electrode. A band-shaped main electrode that outputs the obtained reception signal, and an output unit that outputs an electrical characteristic measurement signal based on the reception signal obtained when the substance mass is placed on the auxiliary electrode and the main electrode. This is a capacitance type substance measuring device.
[0008]
Moreover, the auxiliary electrode and the main electrode are arranged in a plane on the shield substrate via an insulating layer, and the main electrode and the shield substrate are alternately brought to the same potential as the zero potential by the output unit.
[0009]
Further, in the first invention, it is preferable that the auxiliary electrode and the main electrode are covered by a shield case connected to the shield substrate while securing a space for disposing the substance mass.
[0010]
Further, in the first invention, a configuration is also possible in which the auxiliary electrode and the main electrode are arranged so as to be movable with respect to the substance mass.
[0011]
On the other hand, the second invention according to the present invention shields a band-shaped auxiliary electrode to which a predetermined oscillation signal is applied and a band-shaped main electrode for receiving a signal corresponding to impedance formed between the band-shaped auxiliary electrode and the auxiliary electrode. The main electrode and the shield substrate are alternately set to the same potential as the zero potential, and a mass of material is placed on the auxiliary electrode and the main electrode. This is a capacitance-type substance measurement method for measuring electric characteristics of the substance based on an obtained reception signal.
[0012]
In the second invention, a method is also possible in which the electrical characteristics are measured from the received signal obtained by moving the auxiliary electrode and the main electrode with respect to the substance mass.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The method of measuring the capacitance-type substance will be described in the process of describing the capacitance-type substance measurement apparatus.
FIG. 1 and FIG. 2 are a diagram showing a capacitance type substance measuring apparatus according to the present invention and a schematic perspective view of a principal part.
[0014]
1 and 2, a conductive substrate 1 is formed from a conventionally known conductive plate into a flat and elongated trapezoidal shape having a U-shaped cross section, and an insulating layer 3 is formed on almost the entire upper surface of the top plate 1a. ing.
On the insulating layer 3 of the conductive substrate 1, strip-shaped elongated auxiliary electrodes 5 and a main electrode 7 are formed in parallel at a predetermined interval, and extend along the longitudinal direction of the conductive substrate 1.
[0015]
The auxiliary electrode 5 and the main electrode 7 are formed by a conventionally known method, are opposed to each other in a planar manner with their thicknesses, and face the conductive substrate 1 via the insulating layer 3.
The conductive substrate 1 is covered with a conductive shield case 11 having a U-shaped cross section with a space on the auxiliary electrode 5 and the main electrode 7 where a porous substance mass 9 as an object to be measured is arranged. Are electrically connected to, for example, the leg 1 b of the conductive substrate 1.
[0016]
In the substance mass 9, for example, in the case of a porous substance, as shown in FIG. 3, bubbles 9 b are formed in a porous portion 9 a processed by mixing a foam stabilizer and the like. In addition, although there are minute bubbles in the porous portion 9a, they are not shown for convenience.
As shown in FIG. 1, the auxiliary electrode 5 is connected to a signal source 13 which oscillates and outputs an AC signal Vg of, for example, 40 KHz whose level is stable.
[0017]
The main electrode 7 is connected to an inverting input terminal of an OP (op) amplifier 17 via a core wire 15a of the shielded cable 15, and a shield portion 15b of the shielded cable 15 is connected to the conductive substrate 1 and a non-inverting input terminal of the OP amplifier 17. It is connected.
The non-inverting input terminal of the OP amplifier 17 is fixed to zero potential (0 potential: ground potential), and its output terminal is connected to the inverting input terminal via the feedback circuit 19 and connected to the rectifying / smoothing unit 21. ing.
[0018]
Therefore, a voltage having the opposite polarity to the voltage applied to the inverting input terminal is output to the output terminal of the OP amplifier 17, and the feedback circuit 19 is appropriately selected so that the non-inverting input terminal and the inverting input terminal are the same in terms of AC. It is at potential.
Accordingly, the OP amplifier 17 functions as an equipotential forming unit 23 for bringing the main electrode 7 into the same electric potential state as zero potential together with the feedback circuit 19, and also converts the output current from the main electrode 7 into a voltage. As a function.
[0019]
The rectifying / smoothing unit 21 rectifies and smoothes an output signal from the OP amplifier 17 and is connected to the comparing unit 25.
The comparison unit 25 receives a reference signal obtained via the OP amplifier 17 or the rectifying / smoothing unit 21 or a reference signal corresponding thereto when the substance mass 9 as a reference product is previously disposed between the auxiliary electrode 5 and the main electrode 7. And outputs the difference between the signal from the rectifying / smoothing unit 21 based on the substance mass 9 to be actually measured and the reference signal as an electrical characteristic measurement signal (output signal).
[0020]
Note that the comparing unit 25 can be simply configured to output the signal from the rectifying / smoothing unit 21 by directly adjusting the level or the like.
That is, the OP amplifier 17, the feedback circuit 19, the rectifying / smoothing unit 21, and the comparing unit 25 output an electrical characteristic measurement signal based on the capacitance (impedance) due to the tissue state of the substance mass 9 as an output signal. An output section 27 is formed.
[0021]
Next, the operation of the capacitance type substance measuring device of the present invention will be described based on the reason that its electrical characteristics can be measured from the impedance of the porous substance mass 9.
As shown in FIG. 4, the porous substance mass 9 can be represented by an equivalent circuit in which parallel circuits for resistance and capacitance are assembled. It can be considered as a circuit distribution of the capacitance C crossing 9b and the resistance formed in the porous portion 9a along the bubble 9b.
[0022]
As shown in FIG. 5, it is considered that a parallel circuit for the resistor R and the capacitor C is connected vertically and horizontally as a whole, and as a whole, the material lump 9 can be considered as one impedance (Z). It is possible.
Since the resistance and the capacitance, particularly the capacitance, change depending on the number and the size of the bubbles 9b, if the substance mass 9 is arranged between the opposed electrodes, the number and the size of the bubbles 9b depend on the number and the size of the bubbles 9b. Thus, electrical characteristics can be measured through a change in impedance between the electrodes.
[0023]
Therefore, as shown in FIG. 6, when one porous substance mass 9 is sandwiched between the auxiliary electrode 29 and the main electrode 31 which are arranged so as to face each other, a signal corresponding to the state of the bubbles 9b of the substance mass 9 is generated. The signal can be received by the main electrode and can be output.
[0024]
That is, as for the substance lump 9, even if the volume of the substance 9 is the same, if the inside bubble 9 b is large, the ratio of the impedance of the bubble 9 b and its surroundings is large, so that the overall impedance is large, and the auxiliary electrode 29 and the main electrode 31. The impedance changes in accordance with the state of the bubbles 9b in the substance mass 9 disposed therebetween, the current based on the electric flux lines reaching the main electrode 31 from the auxiliary electrode 29 connected to the signal source 13 decreases, and the OP amplifier The voltage output value from 17 decreases.
[0025]
1 is connected to the main electrode 31 via the shielded cable 15, the output circuit 27 including the feedback circuit 19, the rectifying / smoothing unit 21, and the comparison unit 25. Can be measured.
Furthermore, this concept is not limited to measurement of a single substance mass 9, but is the same for measurement of a large number of substance masses 9, for example.
[0026]
That is, when a plurality of substance masses 9 are sandwiched between the facing auxiliary electrode 29 and the main electrode 31, the capacitance Ca corresponding to the gap between the adjacent substance masses 9 in the direction between the auxiliary electrode 29 and the main electrode 31 is formed. Then, the impedance between the auxiliary electrode 29 and the main electrode 31 becomes a value obtained by adding the capacitance Ca to the capacitance of each substance mass 9, and a reception signal corresponding to the composite value is obtained from the main electrode 31.
[0027]
Further, the capacitance Cb may be formed between the substance masses 9 adjacent to the auxiliary electrode 29 and the main electrode 31 in a direction perpendicular or oblique to the direction between the auxiliary electrode 29 and the main electrode 31. A value obtained by adding the capacitance Cb to the individual substance mass 9 is obtained, and a reception signal corresponding to the combined value is obtained from the main electrode 31.
In the actual evaluation, the electrical characteristics of the substance mass 9 in a state where FIGS. 7 and 8 are synthesized will be measured.
[0028]
However, although the gap between the adjacent substance masses 9 is different and the external shape is slightly different, for example, since there are many material masses 9 on the transport path, for example, a certain distance (1 m to several m) or a certain period (30 m) is used. It is possible to measure the average value (seconds to several minutes).
In the present invention, as shown in FIG. 6 or FIG. 9, when the auxiliary electrode 29 and the main electrode 31 face each other so as to face each other, the position where the auxiliary electrode 29 and the main electrode 31 overlap with each other in the width in the height direction. When the substance mass 9 is arranged at a position, the height of the substance mass 9 between the auxiliary electrode 29 and the main electrode 31 is output as a value as it is. I have to worry.
[0029]
In addition, when the substance mass 9 is stacked higher than the auxiliary electrode 29 and the main electrode 31, the material mass 9 stacked by the higher mass is compared with the one having the shortest line of electric force existing between the electrodes. The distance is not so different, the difference is small in terms of capacitance, and there is a possibility that the fluctuation in height affects the output.
Therefore, in order to obtain a good measurement result with this arrangement, it may be necessary to take measures such as detecting the height of the substance mass 9 by some method and correcting the output value based on the result. .
[0030]
In this regard, as shown in FIG. 1 or FIG. 10, a configuration in which the auxiliary electrode 5 and the main electrode 7 are opposed to each other in a plane reduces the influence thereof to some extent and is more suitable for actual measurement. .
Moreover, since the substance mass 9 is not disposed between the auxiliary electrode 5 and the main electrode 7, the amount of the measured object is not easily restricted, and the interval between them and the shape of the electrode itself can be reduced, so that the degree of design freedom is improved. I do.
[0031]
By the way, when a person or an object approaches the auxiliary electrode 5 and the main electrode 7, the influence thereof may be expected in the measurement result.
Therefore, as shown in FIG. 1, it is preferable to cover the conductive substrate 1 with the shield case 11 in a state where the space for disposing the substance mass 9 is secured, and to shield the auxiliary electrode 5, the main electrode 7, and the foamed substance mass 9. . That is, they are shielded by the conductive substrate 1 and the shield case 11.
[0032]
When the auxiliary electrode 5, the main electrode 7, and the substance lump 9 are shielded as described above, impedances Zva and Zvb are formed in the substance lump 9 and currents Iva and Ivb flow through the substance lump 9 as shown in FIG. A capacitance Cx is formed between the Zvb network and the shield case 11, and a current Ix flows through the capacitance Cx. The influence from the outside world is removed by the shield, so that an error corresponding thereto is eliminated and good measurement can be performed. FIG. 12 shows FIG. 11 as an equivalent circuit.
[0033]
However, in order to ensure the shielding effect in FIG. 11, when the impedance of the substance lump 9 is Zv and the impedance of the capacitor Cx is Zx, it is limited to the range of Zv << Zx.
The reason is, as can be seen from the equivalent circuit shown in FIG. 12, when the volume of the substance mass 9 increases, the distance between the shield cases 11 decreases → the value of Cx increases → the impedance decreases → the current increases This is because such effects occur and the effects cannot be ignored.
[0034]
Further, in the capacitance type material measuring apparatus of the present invention, the auxiliary electrode 5 and the main electrode 7 arranged in a plane are not limited to the linear band shape as described above.
For example, as shown in FIG. 13, a configuration in which a comb-shaped auxiliary electrode 33 and a main electrode 35 are mutually inserted at predetermined intervals on a conductive substrate 1 via an insulating layer (not shown) (FIG. 13A), A configuration in which a square auxiliary electrode 37 is surrounded by a frame-shaped main electrode 39 at a predetermined interval (FIG. B), and a configuration in which an auxiliary electrode 41 is sandwiched by a plurality of main electrodes 43 at a predetermined interval (FIG. C). A configuration in which the spiral main electrode 47 is concentrically inserted at a predetermined interval between the spiral auxiliary electrodes 45 (FIG. D) can be used.
[0035]
Then, if the conductive substrate 1 shown in FIG. 1 or FIG. 11 is fixedly arranged with respect to the transport path of the substance lump 9, automatic measurement of the substance lump 9 moving on the transport path can be easily performed. It is optional to individually collect and measure the substance mass 9.
The arrangement of the conductive substrate 1 and the like may be arranged on the lower side of the mass of material 9, for example, when measuring a substance having a specific gravity lower than that of air (eg, a balloon filled with gas). It is.
[0036]
Further, in the capacitance type substance measuring apparatus of the present invention, the conductive substrate 1 having the auxiliary electrode 5 and the main electrode 7 is fixedly arranged at a stationary position with respect to the substance mass 9 to be conveyed as described above. In addition to the above configuration, if the auxiliary electrode 5 and the main electrode 7 are moved (scanned) with respect to the substance mass 9 whose position is stopped during the measurement period, automatic measurement can be performed without transporting the object to be measured. It becomes.
[0037]
By the way, if the capacitance-type substance measuring method according to the present application is described, the auxiliary electrode 5 to which an oscillation signal is applied and the main electrode 7 that receives a signal based on impedance formed between the auxiliary electrode 5 and the auxiliary electrode 5 are used. A substance mass 9 is arranged between the auxiliary electrode 5 and the main electrode 7 to output an electrical characteristic measurement signal based on a reception signal obtained from the main electrode 7 or a material mass 9 as a reference product in advance. The difference from the reference signal obtained in step 9 is output as an electrical characteristic measurement signal.
[0038]
In addition, in this capacitance-type substance measurement method, the auxiliary electrode 5 and the main electrode 7 are fixedly arranged in the middle of the transport path to measure the electrical characteristics of the substance mass 9 to be transported. Based on the received signal obtained by moving (scanning) the electrode 5 and the main electrode 7 with respect to the substance mass 9, it is possible to measure the electrical characteristics thereof.
[0039]
Further, the configuration of the output unit 27 described above is merely an example, and various other configurations are possible.
In addition, as a porous substance as an evaluation object in the present invention, in addition to "pumice", for example, "sponge", "porous ceramics", "foamed plastics", and used or ingested in daily life It is also possible to measure substances.
[0040]
Further, the present invention is not limited to products having a porous structure such as a foamed structure, and can be widely applied to those in which the electrical characteristics (impedance) value of a substance is determined by the state of internal bubbles as a measurement factor of the substance. It can also be applied to the measurement of the presence or absence of substances and the presence or absence of substances.
[0041]
【The invention's effect】
As described above, the substance measuring device according to the first configuration of the present invention has a band-shaped auxiliary electrode to which a predetermined oscillating signal is applied, and a band-shaped auxiliary electrode which is disposed to face the auxiliary electrode according to the impedance between the auxiliary electrode and the auxiliary electrode. A main electrode in the form of a strip for outputting the received signal obtained by the above, and an output unit for outputting an electrical characteristic measurement signal based on the received signal obtained in accordance with the auxiliary electrode and the mass of material placed on the main electrode. Since the auxiliary electrode and the main electrode are arranged in a plane on the shield substrate via an insulating layer, and the main electrode and the shield substrate are alternately brought to the same potential as 0 potential by the output portion, Electrically and quantitatively measure the electrical properties of a substance whose electrical properties are determined by the tissue state formed therein, without the tester's feeling or visual observation. Terms of the ability, it is possible to suppress the measurement error based on the amount of the height direction of the material mass.
In the first invention, if the auxiliary electrode and the main electrode are covered with a shield case connected to the shield substrate in a state where the space for disposing the substance mass is secured, the influence of impedance from outside can be reduced. The measurement error based on the external environment can be reduced.
The substance measuring method according to the second aspect of the present invention includes a band-shaped auxiliary electrode to which a predetermined oscillation signal is applied, and a band-shaped main electrode for receiving a signal corresponding to impedance formed between the band-shaped auxiliary electrode and the auxiliary electrode. Are placed in a plane on the shield substrate with an insulating layer interposed therebetween, and the main electrode and the shield substrate are alternately brought to the same potential as the 0 potential, and a substance mass is placed on the auxiliary electrode and the main electrode. Since the electrical characteristics measurement signal is output based on the received signal obtained from the main electrode, the substance whose electrical properties are determined by the tissue state formed in the substance is not sensed or visually checked by the tester. Measurement and determination can be performed electrically from outside the substance.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of a capacitance type substance measuring device according to the present invention; FIG. 2 is a schematic perspective view showing an outline of a base, an auxiliary electrode, a main electrode and a shield case in FIG. 1; It is.
FIG. 3 is a sectional view showing a substance mass measured in the present invention.
FIG. 4 is an enlarged equivalent circuit diagram showing an electrical configuration of the substance mass of FIG. 3;
FIG. 5 is an equivalent circuit diagram showing an electrical configuration of the entire substance mass of FIG. 3;
FIG. 6 is a diagram illustrating the concept of measuring a substance mass in the substance measuring apparatus and method of the present invention.
FIG. 7 is a view for explaining the concept of measuring a substance mass in the substance measuring device and method of the present invention.
FIG. 8 is a view for explaining the concept of measuring a substance mass in the substance measuring apparatus and method of the present invention.
FIG. 9 is a diagram for explaining the concept of measuring a substance mass in the substance measuring apparatus and method of the present invention.
FIG. 10 is a diagram illustrating the concept of measuring a substance mass in the substance measuring device and method of the present invention.
FIG. 11 is a view for explaining the concept of measuring a substance mass in the substance measuring apparatus and method of the present invention.
FIG. 12 is an equivalent circuit diagram formed in a substance mass to be evaluated in the substance measuring device of FIG.
FIG. 13 is a diagram showing another configuration of the auxiliary electrode and the main electrode used in the substance measuring device of the present invention.
[Explanation of symbols]
1 conductive substrate (shield substrate)
1a Top plate 1b Leg 3 Insulating layer 5, 29, 33, 37, 41, 45 Auxiliary electrode 7, 31, 35, 39, 43, 47 Main electrode 9 Material lump (measured object)
9a Porous portion 9b Bubble 11 Shield case 13 Signal source 15 Shield cable 15a Core wire 15b Shield portion 17 OP (op) amplifier 19 Feedback circuit 21 Rectifying smoothing portion 23 Same potential forming portion 25 Comparison portion 27 Output portion

Claims (3)

In a device for measuring the electrical properties of the substance determined by the tissue state of the substance mass,
A belt-shaped auxiliary electrode to which a predetermined oscillation signal is applied,
A belt-shaped main electrode that is arranged to face the auxiliary electrode and outputs a reception signal obtained according to the impedance between the auxiliary electrode and
An output unit that outputs the electrical characteristic measurement signal based on the reception signal obtained when the substance mass is placed on the auxiliary electrode and the main electrode,
With
The auxiliary electrode and the main electrode are arranged in a plane on a shield substrate via an insulating layer, and the main electrode and the shield substrate are alternately brought to the same potential as 0 potential by the output unit. Capacitance type material measuring device. The capacitance-type substance measuring device according to claim 1, wherein the auxiliary electrode and the main electrode are covered by a shield case connected to the shield substrate while securing a space for disposing the substance mass. In a method of measuring an electrical property of a substance determined by a tissue state of a substance mass,
A band-shaped auxiliary electrode to which a predetermined oscillation signal is applied and a band-shaped main electrode for receiving a signal corresponding to impedance formed between the auxiliary electrode and the band-shaped auxiliary electrode are arranged in a plane on a shield substrate via an insulating layer. At the same time, the main electrode and the shield substrate are alternately brought to the same potential state as the zero potential, the substance mass is placed on the auxiliary electrode and the main electrode, and the electric power of the substance is set based on a reception signal obtained from the main electrode. A capacitance type substance measuring method characterized by measuring a characteristic characteristic.

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