JP2002277426A - Dielectric physical property measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric physical property measuring instrument capable of well measuring dielectric physical properties and well receiving a sample even in such a case that a conductive material or an electrolytic material is contained in a dielectric. SOLUTION: In a moisture measuring instrument 1, a sensor 2 is constituted of a cylindrical receiving part 15 formed of an electric insulating material and a pair of the electrode plates 6 and 7 provided on the outer surface of the receiving part 15. By this constitution, since the receiving part 15 shields the energization due to the conductive material or the electrolytic material between the electrode plates 6 and 7 even if the conductive material or the electrolytic material is contained in a sample S, the content of moisture can be measured by detecting dielectric loss and electrostatic capacity. Further, since the electrode plates 6 and 7 are provided on the outer surface of the receiving part 15, the passage or reception of the sample S is not obstructed and good measurement can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring dielectric properties, and more particularly, to an apparatus for measuring dielectric properties which can be used for an apparatus for measuring water content of a dielectric.

[0002]

2. Description of the Related Art Conventionally, a dielectric constant measurement method has been known as a method for measuring the moisture of a substance. This dielectric constant measurement method focuses on the fact that the dielectric constant of water is large, and arranges a dielectric material as a sample between opposed electrodes, and measures the change in capacitance at that time by an electrical method, It measures the moisture content of the dielectric, for example, paper, pulp,
It is widely used for industrially measuring moisture contained in industrial products such as coal, cereals, wood, and cloth.

In such a dielectric constant measuring method, usually,
The counter electrodes are made of metal and are arranged at equal distances from each other.

[0004]

However, in the dielectric constant measurement method, when a conductive substance or an electrolytic substance is contained in a dielectric substance as a sample, an electric current flows between the opposed electrodes, so that the static electricity is measured. The capacity cannot be measured by an electrical method, and therefore, it is difficult to measure the moisture contained in such a sample by a dielectric constant measurement method.

[0005] For example, when moisture is continuously measured, a pair of concentrically formed double electrodes is often used, but an inner electrode (internal electrode) passes through the sample. This causes a bridging phenomenon in the powder or the like, causing clogging.

[0006] The present invention has been made in view of such circumstances, and an object of the present invention is to improve dielectric properties even when a conductive substance or an electrolytic substance is contained in a dielectric. It is an object of the present invention to provide a dielectric property measuring device capable of measuring and receiving a sample well.

[0007]

According to one aspect of the present invention, there is provided an apparatus for measuring dielectric properties, comprising: a receiving portion having an electrical insulation property for receiving a sample; At least two electrodes provided on the outer surface of
It is characterized by having.

According to such a configuration, even if a conductive material or an electrolytic substance is contained in the sample, the receiving portion having an electrical insulating property allows the conductive material or the electrolytic substance to flow between the electrodes. Since the shielding is performed, the dielectric properties of the sample can be favorably measured by the electrodes provided on the outer surface thereof.

In addition, since each electrode is provided on the outer surface of the receiving portion, the receiving portion can receive the sample without any hindrance by the electrodes. Therefore, simple and reliable measurement can be achieved.

[0010] The invention described in claim 2 is the same as the claim 1.
In the invention described in (1), each of the electrodes is configured such that a closer part and a farther part are formed at a distance from each other.

According to such a configuration, each electrode can be formed in an appropriate shape and arrangement according to the configuration, purpose, and application of the device without making the distance between the electrodes equal.
The degree of freedom in design and arrangement can be improved.

Further, the invention described in claim 3 is the first invention.
Alternatively, in the invention described in Item 2, the receiving portion has a cylindrical shape.

If the receiving portion is cylindrical, it can be connected to the middle of a circular pipe or joint through which the sample is transported, so that continuous measurement can be performed. It is also possible to measure the sample by connecting it to the end of a probe or a joint and to sample the sample every time, thereby improving the efficiency of the measurement operation.

The invention described in claim 4 is the first invention.
The invention according to any one of the first to third aspects, wherein the electrode is attached to an outer surface of the receiving portion.

According to such a configuration, the device can be simply and reliably configured by simply attaching the electrode to the outer surface of the receiving portion.

According to a fifth aspect of the present invention, there is provided a dielectric property measuring apparatus comprising at least two electrodes, wherein each of the electrodes is formed with a portion closer to and farther from each other. It is characterized by having such a configuration.

According to such a configuration, each electrode can be formed in an appropriate shape and arrangement according to the configuration, purpose, and application of the device without making the distance between the electrodes equal.
The degree of freedom in design and arrangement can be improved.

The invention according to claim 6 is the first invention.
The invention according to any one of the first to fifth aspects, wherein the dielectric property measuring device of the present invention is used as a moisture measuring device.

When the dielectric property measuring apparatus of the present invention is used as a moisture measuring apparatus, the moisture content in a sample containing a conductive substance or an electrolytic substance can be measured. The water content of an industrial product containing a conductive substance or an electrolytic substance, such as a food product containing the same or a plastic product containing a conductive carbon or the like, can be measured favorably.

In addition, since each electrode is provided on the outer surface of the receiving section, the receiving section can receive the sample without being hindered by any electrode. Therefore, simple and reliable moisture measurement can be achieved in both continuous moisture measurement of the sample and moisture measurement by sampling the sample every time, and the application range can be further expanded.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing one embodiment of a moisture measuring device as a dielectric property measuring device of the present invention. In FIG. 1, the moisture measuring device 1 includes a sensor unit 2, a converter unit 3, a data processing unit 4, and a display unit 5.

As shown in FIGS. 2 to 4, the sensor section 2 includes a receiving section 15, a pair of electrode plates 6 and 7, a guard electrode 8 provided on one of the electrode plates 6, and a thermocouple 9. (Omitted in FIGS. 2 to 4).

The receiving portion 15 has a bottomed cylindrical cup shape with one side opened to receive the sample S,
It is formed of a material having electrical insulation. As the material having such electrical insulation properties, for example, plastics, ceramics and the like can be used, and polyolefin-based plastics such as polyethylene and polypropylene, fluorine-based resins such as polytetrafluoroethylene, or glass are preferable. Used. In particular, since the fluororesin has a small dielectric constant and excellent electrical insulation properties, and further has excellent wear resistance and chemical resistance, the receiving portion 15 is more preferably formed by using such a fluororesin. The dielectric properties can be favorably measured, and the durability of the device can be improved.

The pair of electrode plates 6 and 7 are made of metal, have a substantially rectangular thin plate shape, and are adhered to each other along the outer surface of the cylindrical side wall of the receiving portion 15 so as to face each other. ing. As a result, the pair of electrode plates 6 and 7
At a distance from each other, a closer portion is formed at each end in their width direction, and a farther portion is formed at a center portion in their width direction.

The guard electrode 8 is connected to the electrode plates 6 and 7
Provided to stabilize the current value detected from
It is made of metal and has a rectangular thin plate shape slightly larger than the insulating film 16 described below. The guard electrode 8 is formed on one of the electrode plates 6 first.
Rectangular insulating film (insulating paper) 16 slightly larger than
Is attached so as to cover the entire outer surface of the electrode plate 6,
Next, the insulating film 16 is formed by sticking so as to cover the entire outer surface. Thus, the one electrode plate 6 and the guard electrode 8 are cut off from each other by the insulating film 16.

The thermocouple 9 is used as a temperature sensor. Although not shown in FIGS. 2 to 4, the thermocouple 9 is provided at an arbitrary position in the cylinder of the receiving portion 15.

As shown in FIG. 1, the converter section 3 includes an AC power supply 10, an ammeter 11, a detection circuit 12, an A / D converter 13 for detection, and an A / D converter 14 for temperature.

The AC power supply 10 and the ammeter 11 together with the pair of electrode plates 6 and 7 form a closed circuit. That is, the AC power supply 10, the ammeter 11, the one electrode plate 6, and the other electrode plate 7 are sequentially connected by the connection lines, thereby forming a closed circuit by a closed line. A branch connection line is branched from a connection line between the AC power supply 10 and the ammeter 11, and the branch connection line is connected to the guard electrode 8. Also, the detection circuit 1
An AC power supply 10 and an ammeter 11 are connected to 2, respectively, and a detection circuit 12 is connected to a detection A / D converter 13. The thermocouple 9 is connected to a temperature A / D converter 14.

In the converter section 3, the current value applied by the AC power supply 10 changes depending on the sample S present between the pair of electrode plates 6 and 7. And detected by the detection circuit 12 as a specific waveform. In the detected waveform, the change component of the phase shift corresponds to the dielectric loss, and the change component of the magnitude of the amplitude corresponds to the capacitance. The waveform detected by the detection circuit 12 is used as a detection A / D signal.
After being converted into a digital signal by the converter 13, it is transmitted to the data processing unit 4 described below. The temperature detected by the thermocouple 9 is also converted into a digital signal by the temperature A / D converter 14 and then transmitted to the data processing unit 4 described below.

The data processing unit 4 is constituted by a CPU, and is connected to the detection A / D converter 13, the temperature A / D converter 14, and the display unit 5. In the data processing unit 4, the waveform value (dielectric loss and capacitance) of the current transmitted from the detection A / D converter 13 and the temperature value transmitted from the temperature A / D converter 14 ( Temperature), the water content is calculated by a known calculation method. The method of calculating the water content from the dielectric loss, the capacitance, and the temperature may be based on a known method as appropriate, such as the method described in Japanese Patent Publication No. 5-70786. Then, the water content calculated by the data processing unit 4 is L
It is displayed on the display unit 5 composed of an ED or the like.

In the moisture measuring device 1,
Since the sensor section 2 is constituted by the receiving portion 15 formed of an electrically insulating material and the pair of electrode plates 6 and 7 provided on the outer surface of the receiving portion 15, even if the sample S Even if a conductive substance or an electrolytic substance is contained, the receiving portion 15 having electrical insulation shields the conduction between the electrode plates 6 and 7 due to the conductive substance or the electrolytic substance. Thus, the current value that changes due to the presence of the sample S can be detected by the ammeter 11 satisfactorily. Therefore, even if the sample S contains a conductive substance or an electrolytic substance, the detection circuit 1
2, the dielectric loss and the capacitance can be detected, and the data processing unit 4 can calculate the water content.

Therefore, for example, the water content of an industrial product containing a conductive or electrolytic substance, such as a food containing an electrolyte such as a salt or a plastic product containing a conductive carbon or the like, can be measured well. can do.

In particular, the sample S is not, for example, a shell-like or capsule-like (eg, rice or beans) containing a conductive substance or an electrolytic substance, which can be measured conventionally. In the past, it was difficult to measure, a liquid state containing a conductive substance and an electrolytic substance,
Mud-like or slurry-like (for example, margarine, candy, red bean paste, jam, etc.) and powdered particles such as resin pellets containing conductive powder (for example, resin containing metal powder or carbon powder) Since the moisture content of the pellet S) can be measured, such a sample S can be suitably used in the fields of, for example, foods, cosmetics, plastics, and the like, which are to be measured.

In addition, each of the electrode plates 6 and 7 is
Since the sample S is provided on the outer surface of the side wall of the receiving portion 15, the sample S can be received in the cylinder of the receiving portion 15 without being hindered by the electrode plates 6 and 7. Therefore, in the moisture measurement by sampling each time of the sample S, simple and reliable moisture measurement can be achieved, and the application range can be further expanded.

Further, in the sensor section 2, the pair of electrode plates 6 and 7 are arranged to face each other along the outer surface of the cylindrical side wall of the receiving portion 15, so that the pair of electrode plates 6
7 and 7, a closer part is formed at each end in the width direction of each other, and a farther part is formed at a center part in the width direction. Therefore, the distance between the pair of electrode plates 6 and 7 is not always equal, and the density of the electric field differs between each end portion and each center portion. Needs only to be able to detect a current value that changes due to the presence of the sample S, and therefore does not cause any inconvenience. Therefore, in the moisture measuring device 1, the electrode plates 6 and 7 are appropriately shaped and arranged according to the shape and configuration of the receiving unit 15 and the purpose and application as described above, and the degree of freedom in design and arrangement is increased. Has been raised.

Further, in the sensor section 2, the receiving section 15
Has a cylindrical shape with a bottom, so that it can be connected to an end of a circular pipe or a joint for transporting the sample S, and can be measured by sampling the sample S every time. Can be achieved. Further, since the pair of electrode plates 6 and 7 are only attached to the outer surface of the receiving portion 15, the configuration is simple and reliable.

Further, as shown in FIG.
It may be formed in a cylindrical shape that can be inserted without a bottom. By forming the receiving portion 15 in this way, it is possible to perform continuous measurement by connecting the sample S in the middle of a circular pipe or a joint for transporting the sample S, thereby improving the efficiency of the measurement operation. Can be.

That is, for example, when moisture is continuously measured, a pair of electrodes formed in concentric circles is often used, but the inner electrode (internal electrode) passes through the sample S. This causes a bridging phenomenon in the powder and the like, which causes clogging. However, by providing the pair of electrodes 6 and 7 on the outer surface of the cylindrical receiving portion 15 as described above, such an inner electrode (internal electrode) becomes unnecessary, and therefore, the sample S is supplied to the receiving portion 15. Without blocking the passage at
Good continuous measurement can be performed on a powdery material without causing a bridging phenomenon.

In this moisture measuring apparatus 1, the moisture content was measured from capacitance and dielectric loss as dielectric properties and temperature, but in the present invention, a basic configuration of the apparatus is a pair of electrodes and an oscillator. (E.g., AC power supply) and sensing means (e.g., ammeter or voltmeter)
The dielectric property is not limited to the above-described moisture measuring device 1 as long as it measures at least capacitance and / or dielectric loss.

Further, the shape of the receiving portion 15 is not limited to the above-mentioned cylindrical shape, but may be formed into a shape such as a square shape according to the purpose and application, and the pair of electrodes 6 and 7 may also be formed. May be arranged corresponding to the shape. For example, in the above embodiment, the pair of electrodes 6 and 7 are curvedly opposed to each other, but may be arranged in a C shape so that one is wider and the other is narrower. Also, the shape of the pair of electrodes 6 and 7 may be other than a substantially rectangular thin plate shape such as a substantially circular thin film shape.

In the above embodiment, the cylindrical shape includes various shapes having a curved surface without an angle such as an ellipse.

[0042]

As described above, according to the first aspect of the present invention, even if the sample contains a conductive substance or an electrolytic substance, the dielectric properties of the sample can be measured well. be able to. In addition, the sample can be well received, and simple and reliable measurement can be achieved.

According to the second aspect of the present invention, each electrode can be formed in an appropriate shape and arrangement according to the configuration, purpose and application of the device, and the degree of freedom in design and arrangement is improved. be able to.

According to the third aspect of the present invention, continuous measurement can be carried out by connecting the sample to the middle of a circular pipe or joint for transporting the sample. It can be connected to the end of the pipe or joint, and can be measured by sampling the sample every time, and the efficiency of the measurement operation can be improved.

According to the fourth aspect of the present invention, the device can be simply and reliably constructed simply by sticking the electrode to the outer surface of the receiving portion.

According to the fifth aspect of the present invention, each electrode can be formed in an appropriate shape and arrangement according to the configuration, purpose and application of the device, and the degree of freedom in design and arrangement is improved. be able to.

According to the invention described in claim 6, for example, a conductive substance or an electrolytic substance is contained, such as a food containing an electrolyte such as a salt or a plastic product containing a conductive carbon. It can measure the water content of industrial products well, and accept samples well,
Since simple and reliable moisture measurement can be achieved,
The range of application can be further expanded.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a moisture measuring device as a dielectric property measuring device of the present invention.

FIG. 2 is a schematic configuration perspective view showing a sensor unit.

FIG. 3 is a side sectional view of FIG. 2;

FIG. 4 is a plan sectional view of FIG. 2;

FIG. 5 is a side sectional view corresponding to FIG. 3, showing a sensor unit of an embodiment different from that of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moisture measuring device 6 Electrode plate 7 Electrode plate 15 Receiving part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Fujioka 501-17 Fukushima Miyano-mae, Mita City, Hyogo Prefecture Inside the Kawata Mita Plant (72) Inventor Tadashi Ishikawa 501-17 Fukushima Miyano-mae, Mita City, Hyogo Prefecture Co., Ltd. F-term in Kawata-Mita factory (reference) 2G060 AA11 AA12 AA14 AC01 AF11 AG11 AG15 HA02 HC13

Claims (6)

[Claims] 1. An apparatus for measuring dielectric properties, comprising: a receiving part having electrical insulation and receiving a sample; and at least two electrodes provided on an outer surface of the receiving part. 2. The dielectric property measuring apparatus according to claim 1, wherein each of the electrodes is configured such that a closer portion and a farther portion are formed at a distance from each other. 3. The dielectric property measuring device according to claim 1, wherein the receiving portion has a cylindrical shape. 4. The dielectric property measuring device according to claim 1, wherein the electrode is attached to an outer surface of the receiving portion. 5. An apparatus for measuring dielectric properties, comprising at least two electrodes, wherein each of said electrodes is formed such that a portion closer to and farther away from each other is formed. 6. The dielectric property measuring device according to claim 1, wherein the device is used as a moisture measuring device.