JP5958098B2 - Dielectric constant measuring apparatus and dielectric constant measuring method - Google Patents

Description

  The present invention relates to a dielectric constant measuring apparatus and a dielectric constant measuring method.

  As a technique for measuring the dielectric constant (or relative dielectric constant) of a substance, a technique for arranging a pair of electrodes (counter electrodes) on a measurement target substance and measuring the dielectric constant of the substance based on the capacitance between the electrodes It has been known. 2. Description of the Related Art A technique is known in which snow or soil is used as a dielectric constant measurement target, the capacitance and dielectric constant of snow or soil are measured using electrodes, and the density of snow or the moisture content of the soil is obtained from the measured values.

No. 07-004599 Japanese Patent Laid-Open No. 06-288888 JP 2001-021518 A

  When measuring the dielectric constant, if the gap between the electrode parts (electrodes or sensor part including the electrodes) is filled with the substance to be measured without gaps, the capacitance and dielectric constant of the substance should be measured relatively easily. Can do. However, if there is a gap between the electrode portion and the substance to be measured, the capacitance decreases compared to the case where there is no gap, and there is a possibility that the appropriate dielectric constant of the substance cannot be obtained. For example, when the measurement object is snow, a gap may be formed between the electrode portion and the electrode due to melting snow during measurement. Moreover, when a measuring object is soil, it may happen that an electrode part cannot be arrange | positioned without a clearance gap by the form of the soil.

According to an aspect of the present invention, a first detection unit including a first electrode and a second electrode, a second detection unit including a third electrode and a fourth electrode, and a first detection unit between the first electrode and the second electrode. A first measurement mode for measuring a sum of one capacitance and a second capacitance between the third electrode and the fourth electrode; and a first measurement mode between the first detection unit and the second detection unit. A switching unit for switching between a second measurement mode for measuring three capacitances, a first signal corresponding to the sum of the first capacitance and the second capacitance, and a third capacitance. A storage unit in which information about the second signal is stored, and a sum of the first capacitance and the second capacitance , the third capacitance, and the information ; look including a calculator for calculating the dielectric constant of the analyte provided between the second detection unit, wherein the information, the first detection portion and said First data indicating the relationship between the first signal and the second signal when there is no gap between the two detection units and the measurement target substance, the first detection unit, the second detection unit, and the measurement Including a second data indicating a relationship between the first signal and the second signal when there is a gap between the target substance and the arithmetic unit, the first capacitance to be measured and the second data There is provided a dielectric constant measuring apparatus that compares the sum of the electrostatic capacity and the third electrostatic capacity with the first data and the second data, and calculates a dielectric constant of the substance to be measured. Furthermore, according to one aspect of the present invention, a first detection unit including a first electrode and a second electrode, a second detection unit including a third electrode and a fourth electrode, and between the first electrode and the second electrode. A first measurement mode for measuring the sum of the first capacitance and the second capacitance between the third electrode and the fourth electrode, and between the first detection unit and the second detection unit. A switching unit for switching to a second measurement mode for measuring the third capacitance of the first capacitance, a first signal corresponding to the sum of the first capacitance and the second capacitance, and the third capacitance A storage unit storing information related to the corresponding second signal, and the first detection using the sum of the first capacitance and the second capacitance, the third capacitance, and the information. And a calculation unit for calculating a dielectric constant of a measurement target substance provided between the first detection unit and the second detection unit. A first linear function indicating a relationship between the first signal and the second signal when there is no gap between the second detection unit and the measurement target substance; and the second signal and the measurement target substance A second linear function indicating a relationship with a dielectric constant, and a rate of change of the second signal and a rate of change of the first signal when the dielectric constant of the substance to be measured is constant and the thickness of the gap changes. The calculation unit includes a third linear function using the sum of the first capacitance and the second capacitance to be measured, the third capacitance, and the ratio. And obtaining the value of the second signal at the intersection of the third linear function and the first linear function, and using the value and the second linear function, the dielectric of the substance to be measured is obtained. A dielectric constant measurement device for calculating a ratio is provided.

  According to another aspect of the present invention, a dielectric constant measurement method using a dielectric constant measuring apparatus is provided.

  According to the disclosed technology, even when there is a gap between the detection unit and the measurement target substance, it is possible to correct the influence of the gap and measure the appropriate dielectric constant of the measurement target substance.

It is explanatory drawing of an example of a dielectric constant measurement. It is FIG. (1) which shows an example of a dielectric constant measuring apparatus. It is FIG. (2) which shows an example of a dielectric constant measuring apparatus. It is a figure which shows typically the mode of the electric field at the time of 1st measurement. It is a figure which shows typically the mode of the electric field at the time of 2nd measurement. It is a figure which shows an example of the relationship between a 1st signal and a 2nd signal. It is a figure which shows an example of a dielectric constant measurement flow. It is a figure which shows an example of the processing flow of a dielectric constant measuring apparatus. It is a figure which shows the model of the detection part of a dielectric constant measuring apparatus. It is a figure which shows the relationship between the 1st signal calculated | required by the finite element analysis using the model of FIG. 9, and a 2nd signal. It is explanatory drawing of an example of the method of calculating | requiring a dielectric constant. It is explanatory drawing of another example of the method of calculating | requiring a dielectric constant. It is a figure which shows an example of the relationship between a clearance gap and the calculated dielectric constant. It is a figure which shows an example of the detection part of a dielectric constant measuring apparatus. It is a figure which shows the structural example of the hardware of the computer used for a dielectric constant measuring apparatus.

  For example, soil or snow is used as a measurement target, and the dielectric constant (or relative dielectric constant) of such a measurement target substance is measured. Dielectric constant measurement of soil can be used to predict the risk of soil moisture management, landslides, etc. in the agricultural field, and snow permittivity measurement can be used to determine the weight of snow, It can be used for quantity prediction.

FIG. 1 is an explanatory diagram of an example of dielectric constant measurement.
The dielectric constant of the measurement target substance 100 such as soil or snow can be obtained from the capacitance between the pair of electrodes 101 and 102 placed in the measurement target substance 100. In the simplest case, the relationship between the capacitance and the dielectric constant of the measurement target substance 100 can be expressed by the following equation (1) for a pair of opposed parallel plate electrodes.

C = ε × S / d (1)
In Expression (1), C is the capacitance, ε is the dielectric constant of the measurement target substance 100, S is the area of the electrode 101 and the electrode 102, and d is the distance between the electrode 101 and the electrode 102.

  When the distance between the electrode 101 and the electrode 102 is large, etc., it may deviate from the relationship of the expression (1). However, by preparing calibration data, the capacitance is appropriately obtained and measured from the capacitance. An appropriate dielectric constant of the target substance 100 can be obtained. In addition, the electrodes are arranged in parallel on a plane without facing each other, and the dielectric constant is obtained from the capacitance between the electrodes arranged in parallel.

  As shown in FIG. 1, the pair of electrodes 101 and 102 are connected to the detection unit 103. When measuring the capacitance, the detection unit 103 is used, an AC voltage signal is applied to one of the electrodes 101 and 102 (application electrode), and the current value that flows to the other electrode (detection electrode). Is detected. Since the alternating current amplitude is proportional to the capacitance, the capacitance is obtained from the detected current value, and the dielectric constant is obtained from the capacitance.

  By the way, when obtaining the dielectric constant of the measurement target substance from the capacitance between the electrodes in this way, it is assumed that the measurement target substance is in close contact with the electrode or the sensor unit including the electrode. In the case of a sensor unit including an electrode, the fact that the electrode and the measurement target substance are not in close contact with each other because the electrode is covered with a resin or the like calibrates the relationship between the dielectric constant and the capacitance of the measurement target substance in advance. This can be dealt with. However, since the electrode or the sensor part containing the electrode and the measurement target substance do not adhere to each other and there is a gap between them that does not know the width (thickness), the capacitance decreases compared to the case where there is no gap. It may happen that the dielectric constant of the target substance cannot be measured properly.

  For example, when measuring the dielectric constant of a snow by placing an electrode or a sensor part including an electrode in snow, the temperature of the electrode or the sensor part is caused by energization or by heat conduction from a fixing member of the sensor part. May become higher than the snow, and the snow near the surface may melt, creating a gap. In addition, when the dielectric constant measurement is performed by embedding the electrode or the sensor unit including the electrode in the soil, it is difficult to arrange the electrode or the sensor unit so that there is no gap between the soil and the soil due to the form of the soil. There is.

Therefore, hereinafter, a technique capable of appropriately measuring the capacitance and dielectric constant of a measurement target substance such as snow or soil even in a state where such a gap may exist will be described.
2 and 3 are diagrams showing an example of a dielectric constant measuring apparatus.

  As shown in FIGS. 2 and 3, the dielectric constant measuring apparatus 10 includes a first detection unit 11, a second detection unit 12, an applied voltage signal source 13, a current detection circuit (detection unit) 14, and a measurement mode switching unit 15. Have. Furthermore, as shown in FIG. 3, the dielectric constant measuring apparatus 10 includes a control unit 16, a calculation unit 17, and a memory (storage unit) 18.

  The first detection unit 11 includes a first electrode 11a and a second electrode 11b. Here, a plurality (three as an example) of first electrodes 11a (electrode array) and a plurality (three as an example) of second electrodes 11b (electrode array) are provided, and the first electrode 11a and the second electrode 11b are provided. Exemplifies the first detectors 11 that are alternately spaced apart from each other. The first electrode 11a group is electrically connected to each other, and the second electrode 11b group is electrically connected to each other.

  The second detection unit 12 includes a third electrode 12a and a fourth electrode 12b. Here, a plurality (three as an example) of third electrodes 12a (electrode array) and a plurality (three as an example) of fourth electrodes 12b (electrode array) are provided, and the third electrode 12a and the fourth electrode 12b are provided. The second detectors 12 are illustrated as being alternately arranged apart from each other. The third electrode 12a group is electrically connected to each other, and the fourth electrode 12b group is electrically connected to each other.

  The applied voltage signal source 13 is an alternating current applied to the first electrode 11a group and the third electrode 12a group, or the first electrode 11a group and the second electrode 11b group, which are connected by the measurement mode switching unit 15 as will be described later. It is a signal source for voltage signals.

  The current detection circuit 14 detects a current value flowing through the second electrode 11b group and the fourth electrode 12b group, or the third electrode 12a group and the fourth electrode 12b group connected by the measurement mode switching unit 15 as described later. Circuit.

  The measurement mode switching unit 15 includes a switch 15a for switching the connection of the second electrode 11b group to the applied voltage signal source 13 or the current detection circuit 14, and the applied voltage signal source 13 or current detection circuit 14 of the third electrode 12a group. The switch 15b for switching the connection to the is provided.

  The control unit 16 controls switching of the switch 15a of the measurement mode switching unit 15 and switching of the switch 15b. The control unit 16 controls the operation of the applied voltage signal source 13 and the current detection circuit 14.

  The calculation unit 17 performs a process of calculating a capacitance, a dielectric constant, a relative dielectric constant, and the like using the current value detected by the current detection circuit 14. The calculation process of the calculation unit 17 is controlled by the control unit 16.

The memory 18 stores various data used for calculation processing in the calculation unit 17. The operation of the memory 18 is controlled by the control unit 16.
The dielectric constant measuring apparatus 10 uses the measurement mode switching unit 15 for the four electrode arrays as described above, that is, the first electrode 11a group, the second electrode 11b group, the third electrode 12a group, and the fourth electrode 12b group. Two types of measurements are made for capacitance. The first is a capacitance measurement between the first electrode 11a group and the second electrode 11b group of the first detection unit 11, and between the third electrode 12a group and the fourth electrode 12b group of the second detection unit 12. It is a measurement (1st measurement) including the electrostatic capacitance measurement. The second is measurement (second measurement) including capacitance measurement between the first detection unit 11 and the second detection unit 12.

First, the first measurement (first measurement mode) will be described.
In the first measurement, the capacitance between the first electrode 11a group and the second electrode 11b group and the capacitance between the third electrode 12a group and the fourth electrode 12b group are measured, and the two static electricity is measured. The sum of the capacitances is measured as the first signal.

  In the first measurement, the switch 15a of the measurement mode switching unit 15 is connected to the contact q in FIG. 2, and the switch 15b is connected to the contact r in FIG. As a result, the first electrode 11 a group and the third electrode 12 a group are connected to the applied voltage signal source 13, and the second electrode 11 b group and the fourth electrode 12 b group are connected to the current detection circuit 14. The current value detected by the current detection circuit 14 from this state is the electrostatic capacity between the first electrode 11a group and the second electrode 11b group, and the electrostatic capacity between the third electrode 12a group and the fourth electrode 12b group. The signal corresponds to the sum of the capacitance.

  In the arithmetic unit 17, a signal (current value) detected by the current detection circuit 14 is used, the capacitance between the first electrode 11a group and the second electrode 11b group, the third electrode 12a group, and the fourth electrode. A first signal indicating the sum of the capacitance between the groups 12b is calculated.

  In this way, the switch 15a and the switch 15b of the measurement mode switching unit 15 are switched, the first electrode 11a group and the third electrode 12a group are applied electrodes, the second electrode 11b group and the fourth electrode 12b group are detection electrodes, A measurement mode for measuring a signal is referred to as a first measurement mode.

Next, the second measurement (second measurement mode) will be described.
In the second measurement, the capacitance between the first detection unit 11 and the second detection unit 12 is measured as a second signal.

  In the second measurement, the switch 15a of the measurement mode switching unit 15 is connected to the contact p in FIG. 2, and the switch 15b is connected to the contact s in FIG. Thereby, the first electrode 11a group and the second electrode 11b group of the first detection unit 11 are connected to the applied voltage signal source 13, and the third electrode 12a group and the fourth electrode 12b group of the second detection unit 12 are detected by current. The circuit 14 is connected. The current value detected by the current detection circuit 14 from this state becomes a signal corresponding to the capacitance between the first detection unit 11 and the second detection unit 12.

In the calculation unit 17, a signal (current value) detected by the current detection circuit 14 is used, and a second signal indicating the capacitance between the first detection unit 11 and the second detection unit 12 is calculated.
There is a space of a certain distance D1 between the first electrode 11a and the second electrode 11b of the first detector 11 and between the third electrode 12a and the fourth electrode 12b of the second detector 12, but this space Is set to be smaller than the distance D <b> 2 between the first detector 11 and the second detector 12. For example, the distance D1 is set to a range of 20% to 30% of the distance D2. By doing in this way, the 1st detection part 11 and the 2nd detection part 12 behave like one big electrode, respectively, and it becomes possible to measure the electrostatic capacitance (2nd signal) between them. .

Thus, in 2nd measurement, the 1st detection part 11 and the 2nd detection part 12 are each considered as one electrode, and the electrostatic capacitance (2nd signal) between them is measured.
In this way, the switch 15a and the switch 15b of the measurement mode switching unit 15 are switched, the first electrode 11a group and the second electrode 11b group are applied electrodes, the third electrode 12a group and the fourth electrode 12b group are detection electrodes, and the second A measurement mode for measuring a signal is referred to as a second measurement mode.

  Relationship between the first electrode 11a group, the second electrode 11b group, the third electrode 12a group, and the fourth electrode 12b group as the application electrode or the detection electrode in the first measurement and the second measurement as described above Are summarized in Table 1.

The first measurement (first measurement mode) and the second measurement (second measurement mode) will be further described.
FIG. 4 is a diagram schematically showing the state of the electric field during the first measurement.
FIG. 4 illustrates a situation where the first detection unit 11 and the second detection unit 12 are arranged in the measurement target substance 20 having a dielectric constant (relative dielectric constant). The 1st detection part 11 contains the 1st electrode 11a group and the 2nd electrode 11b group in the main body 11c, and the 1st electrode 11a and the 2nd electrode 11b are mutually spaced apart and are arrange | positioned alternately. The 2nd detection part 12 contains the 3rd electrode 12a group and the 4th electrode 12b group in the main part 12c, and the 3rd electrode 12a and the 4th electrode 12b are mutually spaced apart and are arranged alternately.

  In the first measurement, for example, in the case of the first detection unit 11, the first electrode 11a group that is an application electrode and the second electrode 11b group that is a detection electrode are adjacent to each other. Therefore, as shown in FIG. 4, in the first detection unit 11, the electric field 31 spreads in the vicinity of the surface. Similarly, in the case of the 2nd detection part 12, the 3rd electrode 12a group which is an application electrode, and the 4th electrode 12b group which is a detection electrode are adjacent. Therefore, as shown in FIG. 4, in the 2nd detection part 12, the electric field 32 spreads in the surface vicinity.

  Since the electric field 31 spreads in the vicinity of the surface of the first detection unit 11 and the electric field 32 spreads in the vicinity of the surface of the second detection unit 12 in this way, the acquired signal (current value or first signal) is the first detection unit. 11 is greatly influenced by the state near the surface of 11 and the state near the surface of the second detector 12.

  As shown in FIG. 4, there is a gap 41 (for example, air) with a constant thickness from the surface of the first detection unit 11, and a gap 42 (for example, air) with a constant thickness from the surface of the second detection unit 12. Suppose it exists. When the gap 41 and the gap 42 exist, the obtained signal becomes smaller than when the gap 41 does not exist, and the obtained signal tends to become smaller as the existing gap 41 and gap 42 become larger. The dielectric constant measuring apparatus 10 corrects the influence of the gap 41 and the gap 42 on the capacitance between the first detection unit 11 and the second detection unit 12 from the signal acquired in the first measurement as described above. Used for.

  If the thickness of the gap 41 and the gap 42 becomes too large compared to the spread of the electric field 31 and the electric field 32, the obtained signal becomes almost constant regardless of the thickness, and the influence of the gap 41 and the gap 42 is corrected. It may not be possible. The spread of the electric field 31 and the electric field 32 is, for example, the distance between the first electrode 11a and the second electrode 11b adjacent to each other in the first detection unit 11, and the third electrode 12a and the fourth electrode adjacent to each other in the second detection unit 12. It is the same as or smaller than the distance between 12b. Therefore, it is desirable that the distance between the first electrode 11a and the second electrode 11b and the distance between the third electrode 12a and the fourth electrode 12b be larger than the thicknesses of the assumed gap 41 and gap 42. .

FIG. 5 is a diagram schematically showing the state of the electric field during the second measurement.
In the second measurement, the first electrode 11a group and the second electrode 11b group of the first detection unit 11 serve as application electrodes, and the third electrode 12a group and the fourth electrode 12b group of the second detection unit 12 serve as detection electrodes. Therefore, an electric field 33 is generated from the first detection unit 11 toward the second detection unit 12. In the second measurement, the capacitance between the first detection unit 11 and the second detection unit 12 is measured in the same manner as measuring the capacitance between the two electrodes.

  Now, as shown in FIG. 4 and FIG. 5 described above, if a gap 41 and a gap 42 (for example, air) are present on the surface of the first detector 11 and the surface of the second detector 12, respectively, the electric field 33 Crosses the gap 41 and the gap 42. Since the dielectric constants of the gap 41 and the gap 42 are smaller than the dielectric constant of the measurement target substance 20, the acquired signal (current value or second signal) is compared with the case where the gap 41 and the gap 42 do not exist. Decrease. The thickness of the gap 41 and the gap 42 is assumed to be smaller than the distance between the first detection unit 11 and the second detection unit 12, and the influence of the gap 41 and the gap 42 in the second measurement is as follows. Less than the effect in the first measurement.

  The second signal measured in the second measurement is a value reflecting the dielectric constant of the medium (here, the measurement target substance 20, the gap 41, and the gap 42) between the first detection unit 11 and the second detection unit 12. . The second signal is affected by the gap 41 and the gap 42 on the surfaces of the first detection unit 11 and the second detection unit 12, and the signal value decreases relatively gradually as the thickness of the gap 41 and the gap 42 increases. To do. On the other hand, the first signal measured in the first measurement is a value reflecting the dielectric constant of the medium on the surface of the first detection unit 11 and the second detection unit 12. The first signal is relatively sensitive to the effects of the gap 41 and the gap 42 on the surfaces of the first detection unit 11 and the second detection unit 12, and the signal values are compared as the thickness of the gap 41 and the gap 42 increases. Decrease sharply.

  Therefore, it is assumed that the first signal indicates the degree of the gap 41 and the gap 42, and the second signal is corrected by the first signal. Thereby, it becomes possible to correct | amend the influence of the clearance gap 41 and the clearance gap 42 about the measuring object substance 20 between the 1st detection part 11 and the 2nd detection part 12, and to obtain | require the dielectric constant appropriately.

FIG. 6 is a diagram illustrating an example of the relationship between the first signal and the second signal. The horizontal axis of FIG. 6 represents the value of the first signal, and the vertical axis represents the value of the second signal.
First, when the state without the gap 41 and the gap 42 is considered, in both the first measurement and the second measurement, the first signal and the second signal increase almost in proportion to the relative dielectric constant of the medium (the measurement target substance 20). For this reason, the first signal and the second signal have a relationship as indicated by a line 50 (dotted line) in FIG. On the line 50 in FIG. 6, the relative permittivity decreases in the direction of the thick arrow 51, and the relative permittivity increases in the direction of the thick arrow 52.

  In FIG. 6, the line 50 is displayed by subtracting the signal value obtained when the relative dielectric constant of the medium is 1 from the signal values acquired in the first measurement and the second measurement. In addition, the absolute value of the acquired signal is different between the first measurement and the second measurement. In FIG. 6, for convenience, the scaling of the vertical axis and the horizontal axis is adjusted so that the line 50 has an inclination of approximately 45 degrees. Yes.

  Here, the gap 41 and the gap 42 became larger while the signal value located on the line 50 in the state without the gap 41 and the gap 42 remained constant in the relative dielectric constant of the measurement target substance 20. Think about what will happen.

  As described above, the gap 41 and the gap 42 have a relatively small influence on the second signal acquired by the second measurement, but have a relatively large influence on the first signal acquired by the first measurement. . For this reason, the first signal and the second signal have a relationship like a left-down line 60 (60a, 60b, 60c) having a gentler slope than the line 50 as shown in FIG. As the gap 41 and the gap 42 become larger.

  When several values are selected as the relative dielectric constant of the measurement target substance 20 and the lines when the gap 41 and the gap 42 are increased are drawn, the lines 60a, 60b, and 60c in FIG. 6 are obtained. . Lines 60a, 60b, and 60c are lines indicating the relationship between the first signal and the second signal with a constant relative dielectric constant, respectively, and are generally parallel lines. The lines 60a, 60b, and 60c for each relative permittivity are so-called contour lines of the relative permittivity, and are data for obtaining the relative permittivity from the first signal and the second signal (relative permittivity distribution data, distribution). Figure).

  Such distribution data is obtained by modeling the electrode structures of the first detection unit 11 and the second detection unit 12 by finite element analysis, and changing the relative permittivity of the measurement target substance 20 and the thickness of the gap 41 and the gap 42 as conditions. However, it can be created by obtaining the first signal and the second signal. Of course, the distribution data can be created based on experiments, or can be created by other methods. The distribution data prepared in advance is stored in the memory 18 of the dielectric constant measuring apparatus 10.

  Using the first signal acquired in the first measurement and the second signal acquired in the second measurement, the value of each signal is compared with the distribution data as shown in FIG. The relative dielectric constant of the substance 20 can be obtained. Thus, the process which calculates | requires a dielectric constant using distribution data is performed in the calculating part 17 of the dielectric constant measuring apparatus 10. FIG.

An example of a dielectric constant (relative dielectric constant) measurement flow using the dielectric constant measuring apparatus 10 as described above is shown in FIG.
In the dielectric constant measurement using the dielectric constant measuring apparatus 10 having the configuration shown in FIGS. 2 and 3, first, the first detection unit 11 and the second detection unit 12 are disposed on the measurement target substance 20 (steps). S1).

  Next, the switch 15a and the switch 15b of the measurement mode switching unit 15 are connected to the contact q and the contact r, respectively, and the first measurement is performed (step S2), and the switch 15a and the switch 15b are connected to the contact p and the contact s, respectively. Then, the second measurement is performed (step S3).

  In the first measurement of step S2, an AC voltage signal is applied from the applied voltage signal source 13 to the first electrode 11a group and the third electrode 12a group, and the current detection circuit 14 applies the second electrode 11b group and the fourth electrode 12b group. A flowing current value is detected. Based on the current value (amplitude), the computing unit 17 calculates the capacitance as the first signal.

  In the second measurement of step S3, an AC voltage signal is applied from the applied voltage signal source 13 to the first electrode 11a group and the second electrode 11b group, and the current detection circuit 14 applies the third electrode 12a group and the fourth electrode 12b group. A flowing current value is detected. Based on the current value (amplitude), the computing unit 17 calculates the capacitance as the second signal.

  Then, the calculation unit 17 uses the obtained first signal and second signal to calculate the relative dielectric constant of the measurement target substance 20 (step S4). In the calculation unit 17, for example, distribution data 70 that is prepared in advance and stored in the memory 18 and having the relationship illustrated in FIG. 6 is used, and the ratio of the measurement target substance 20 is calculated from the first signal and the second signal. A dielectric constant is required.

  Thus, the surface of the 1st detection part 11 and the 2nd detection part 12 is measured about the measuring object substance 20 by performing the 1st measurement and the 2nd measurement, and using the 1st signal and the 2nd signal obtained by each measurement. Therefore, it is possible to obtain an appropriate relative dielectric constant in which the influence of the gap that may exist is corrected.

  Here, the case where the first measurement (step S2) is performed after the arrangement of the first detection unit 11 and the second detection unit 12 (step S1) and then the second measurement (step S3) is performed is illustrated. In addition, after the arrangement of the first detection unit 11 and the second detection unit 12, the second measurement can be performed and then the first measurement can be performed.

In the dielectric constant measurement as described above, the dielectric constant measuring apparatus 10 executes, for example, the following processing. An example of the processing flow of the dielectric constant measuring apparatus 10 is shown in FIG.
The dielectric constant measuring apparatus 10 connects the switch 15a and the switch 15b of the measurement mode switching unit 15 to the contact q and the contact r, respectively (step S11). As a result, the dielectric constant measuring apparatus 10 enters a state where the first measurement can be performed (first measurement mode). The dielectric constant measuring apparatus 10 applies an alternating voltage signal to the first electrode 11a group and the third electrode 12a group by the applied voltage signal source 13 (step S12), and the current flowing through the second electrode 11b group and the fourth electrode 12b group. The value is detected by the current detection circuit 14 (step S13). The dielectric constant measuring apparatus 10 uses the detected current value to calculate the capacitance as the first signal by the calculation unit 17 (step S14).

  Next, the dielectric constant measuring apparatus 10 connects the switch 15a and the switch 15b of the measurement mode switching unit 15 to the contact p and the contact s, respectively (step S15). As a result, the dielectric constant measuring apparatus 10 enters a state where the second measurement can be performed (second measurement mode). The dielectric constant measuring apparatus 10 applies an AC voltage signal to the first electrode 11a group and the second electrode 11b group by the applied voltage signal source 13 (step S16), and is output from the third electrode 12a group and the fourth electrode 12b group. Current value detected by the current detection circuit 14 (step S17). The dielectric constant measuring apparatus 10 uses the detected current value to calculate the capacitance as the second signal by the calculation unit 17 (step S18).

  Then, the dielectric constant measuring apparatus 10 uses the obtained first signal and second signal, and the arithmetic unit 17 causes the relative dielectric constant of the measurement target substance 20 between the first detection unit 11 and the second detection unit 12 to be measured. Is obtained (step S19). The computing unit 17 obtains the relative dielectric constant of the measurement target substance 20 from the first signal and the second signal using the distribution data 70 prepared in advance and stored in the memory 18.

  In such processing executed by the dielectric constant measuring apparatus 10, each processing operation of the measurement mode switching unit 15, the applied voltage signal source 13, the current detection circuit 14, the calculation unit 17, and the memory 18 is performed by the control unit 16. Controlled by.

Further, the order of the first measurement (steps S11 to S14) and the second measurement (steps S15 to S18) can be switched.
Subsequently, examples of the dielectric constant measurement as described above will be described.

FIG. 9 is a diagram showing a model of the detection unit of the dielectric constant measuring apparatus, and FIG. 10 is a diagram showing a relationship (distribution data) between the first signal and the second signal obtained by finite element analysis using the model of FIG. .
Here, a model 80 as shown in FIG. 9 is used as a model of the first detector 11 and the second detector 12 of the dielectric constant measuring apparatus 10. In the model 80, the distance D2 between the first detector 11 and the second detector 12 is 50 mm. In the model 80, the width D3 of each electrode of the first electrode 11a, the second electrode 11b, the third electrode 12a, and the fourth electrode 12b is 3 mm, and the distance (space) D1 between the electrodes is 12 mm. In addition, the model 80 is one side from the center C of the 1st detection part 11 and the 2nd detection part 12 from a viewpoint of the structural symmetry of the 1st detection part 11 and the 2nd detection part 12, simplification of a finite element analysis, etc. The part is set.

  FIG. 10 shows the relationship between the first signal and the second signal obtained by performing finite element analysis using such a model 80. FIG. 10 illustrates distribution data when the relative permittivity of the measurement target substance is about 3 or less. The relative permittivity of snow is about this level, and FIG. 10 is distribution data effective for use in measuring the permittivity of snow.

  FIG. 10 illustrates a line 50 (dotted line) when the relative dielectric constant is changed when there is no gap between the substances to be measured. Further, FIG. 10 shows a line 60 (line 60a) when the gap is changed while the relative dielectric constant is constant (the values of the relative dielectric constant k are k = 1.5, k = 2, k = 2.5). (K = 1.5), line 60b (k = 2), line 60c (k = 2.5)) are illustrated.

  FIG. 10 shows the same relationship as in FIG. 6 regarding the first signal, the second signal, and the relative dielectric constant. An electrode structure like the model 80 can be said to be a structure that can be used for measuring the relative dielectric constant of the measurement target substance. FIG. 10 shows the result of analysis up to a gap of 3 mm, and the design in which the space D1 between the electrodes shown in the model 80 is 12 mm can be said to be a structure suitable for correcting the gap up to about 3 mm.

  The distribution data as shown in FIG. 10 is prepared in advance, and the relative permittivity of the measurement target substance is obtained by comparing and collating the first signal and the second signal obtained by the measurement with the distribution data. Can do.

  In the distribution data of FIG. 10, if the data of the constant dielectric constant line 60 is prepared for the relative dielectric constants with sufficiently small intervals, the first signal and the second signal obtained by the measurement are simply By comparing with the distribution data, it is possible to obtain the relative dielectric constant of the substance to be measured. In addition, when data of the line 60 having a constant relative dielectric constant is prepared at a certain interval and the first signal and the second signal obtained by the measurement are between the prepared lines 60, an interpolation process is performed. It is also possible to obtain the relative dielectric constant of the substance to be measured.

FIG. 11 is an explanatory diagram of an example of a method for obtaining a relative dielectric constant.
In FIG. 11, data indicating the distribution data line 60a and data indicating the line 60b are prepared for the relative permittivity k1 and the relative permittivity k2, and the measured first signal Xm and second signal Ym are 2 Assume that there is between two lines 60a and 60b. In addition, the slope of the line 50 (dotted line) when there is no gap on the distribution data from the signals when the relative permittivity k1 and relative permittivity k2 when there is no gap is a.

  A line 55 (dotted line) having an inclination a passing through the point Pm (Xm, Ym) corresponding to the measured first signal Xm and second signal Ym is drawn, and this line 55 intersects a line 60a having a constant relative dielectric constant k1. A point P2 that intersects the point P1 and a line 60b with a constant relative dielectric constant k2 is obtained. The distance d1 between the point Pm and the point P1 and the distance d2 between the point Pm and the point P2 are obtained, and the relative dielectric constant k1 and the relative dielectric constant k2 are interpolated by this distance to obtain the relative dielectric constant k corresponding to the point Pm. . The relative dielectric constant k is obtained by the following equation (2).

k = (d2 × k1 + d1 × k2) / (d1 + d2) (2)
In the dielectric constant measuring apparatus 10, for example, the calculation unit 17 uses the first signal Xm and the second signal Ym that are measured and the distribution data stored in the memory 18 to perform such an interpolation process. The relative dielectric constant k of the substance to be measured is obtained.

As a method for obtaining the relative dielectric constant k of the substance to be measured using the first signal Xm, the second signal Ym, and the distribution data, the following method can also be used.
FIG. 12 is an explanatory diagram of another example of a method for obtaining a relative dielectric constant.

  Here, a method of approximating the relationship between predetermined parameters with a straight line (linear function) and using it to determine the relative dielectric constant of the substance to be measured will be described. As shown in FIG. 12, a line 56 (dotted line) indicating the relationship between the first signal X and the second signal Y when there is no gap is approximated by Y = aX + b (a and b are coefficients). A line 66 in the case where the relative permittivity is constant and the size of the gap changes is approximated by a straight line having a slope α (ratio of change rate of the second signal and change rate of the first signal). Further, the relationship between the second signal Y and the relative dielectric constant k when there is no gap is approximated by k = cY + d (c and d are coefficients).

  It is assumed that such information is prepared and the first signal Xm and the second signal Ym are obtained by measurement. In this case, a line 66 having an inclination α passing through the point Pm (Xm, Ym) corresponding to the measured first signal Xm and second signal Ym is drawn, and this line 66 intersects the line 56 when there is no gap. A point P ′ (X ′, Y ′) is obtained. Since the calculation for obtaining the point P 'is the intersection of the two straight lines 56 and 66, it can be obtained by simultaneous equations. Y ′ is expressed as the following equation (3).

Y ′ = a / (a−α) × (Ym−α × Xm) −b × α / (a−α) (3)
The relative dielectric constant k of the substance to be measured can be obtained from k = cY ′ + d using the value of this equation (3). As described above, if the values of the constants a, b, c, d, and α for expressing the distribution data are prepared, the relative dielectric constant is calculated from the measured first signal X and second signal Y. be able to.

  In the dielectric constant measuring apparatus 10, for example, the calculation unit 17 measures the first signal Xm and the second signal Ym measured and the values of constants a, b, c, d, and α stored in the memory 18. The calculation process is executed and the relative dielectric constant k of the measurement target substance is obtained.

  Note that the method using the approximate straight line using the constants a, b, c, d, and α as described above is a very effective method in a relatively narrow relative dielectric constant range. However, in general, the inclination α tends to increase as the relative permittivity increases, and therefore the error may increase when the same constant is used for a relatively wide range of relative permittivity. In that case, it is also possible to use a method in which the relative dielectric constant is divided into a plurality of ranges within a predetermined range, and constants a, b, c, d, and α are properly used for each divided range.

Next, the effect of the method using the approximate straight line using the distribution data shown in FIG. 10 will be described.
FIG. 10 shows lines 60a, 60b, and 60c corresponding to relative dielectric constants k = 1.5, k = 2, and k = 2.5, respectively, as lines 60 having a constant relative dielectric constant. When the respective lines 60a, 60b, and 60c are approximated by straight lines, the slope is 0.32 when k = 1.5, the slope is 0.38 when k = 2, and the slope is 0 when k = 2.5. .44. Further, the line 50 when there is no gap has an inclination a = 1.4. The slope of the constant relative permittivity line 60 varies depending on the relative permittivity k, but here, it is represented by one slope value α = 0.38. The representative value of this slope is the most suitable value when the relative dielectric constant k = 2, and deviates when the relative dielectric constant k = 1.5 and k = 2.5. Therefore, focusing on the case where the relative dielectric constant k = 1.5 as an example, it is examined whether or not the above method using the approximate straight line is effective when the representative value 0.38 is used as the inclination α.

FIG. 13 is a diagram showing an example of the relationship between the gap and the calculated relative dielectric constant.
In FIG. 13, the analysis result of the first signal Xm and the second signal Ym when the relative dielectric constant k = 1.5 is used, and the slope α is set to 0.38 by the method using the above approximate line. The graph 91 shows the result of obtaining the relative dielectric constant k. In FIG. 13, for comparison, a graph 92 shows the result obtained from the second signal Ym by k = cYm + d. This graph 92 corresponds to the calculation of the relative dielectric constant k by the same equation as when there is no gap without correcting the influence of the gap (without correcting the influence of the gap).

  Since a value obtained by finite element analysis under the condition of relative permittivity k = 1.5 is used, the relative permittivity k to be obtained is 1.5. From the graph 91 of FIG. 13, in the method using an approximate straight line, the relative dielectric constant k is obtained with a good accuracy of about 0.02 error. On the other hand, when the relative dielectric constant k is obtained without correcting the influence of the gap, the error of the relative dielectric constant k becomes as large as about 0.11 from the graph 92 in FIG. Thus, even the approximation using one value (representative value) as the slope α of the straight line has an effect of correcting the influence of the gap on the relative dielectric constant in a certain range.

  In the above description, an example is shown in which the first detection unit 11 and the second detection unit 12 of the dielectric constant measurement apparatus 10 are disposed so as to face each other so that the measurement target substance 20 is sandwiched therebetween. In addition, the first detection unit 11 and the second detection unit 12 are juxtaposed on the measurement target material, and the first measurement and the second measurement as described above are performed to obtain the relative dielectric constant of the measurement target material. It is also possible. Even when the first detection unit 11 and the second detection unit 12 are arranged in this way, it is possible to obtain an appropriate relative dielectric constant in which the influence of the gap between the first detection unit 11 and the second detection unit 12 is corrected. Moreover, the detection part of a form as shown in the following FIG. 14 can also be used.

FIG. 14 is a diagram illustrating an example of a detection unit of the dielectric constant measuring apparatus.
In the detection unit 200 shown in FIG. 14, the electrode 201 is disposed in the cylinder 202 and measures the dielectric constant (relative dielectric constant) of the measurement target substance existing around the cylinder 202. The first detection unit 211 and the second detection unit 212 are arranged separately in an upper part and a lower part of the cylinder 202, and each has a structure in which a plurality of line-shaped electrodes 201 are arranged around the cylinder 202. The electrode 201 of the first detection unit 211 includes a plurality of first electrodes 211a and second electrodes 211b that are alternately spaced apart from each other. The electrode 201 of the second detector 212 includes a plurality of third electrodes 212a and fourth electrodes 212b that are alternately spaced apart from each other. The electrical connection of the first electrode 211a group, the second electrode 211b group, the third electrode 212a group, and the fourth electrode 212b group in the dielectric constant measuring apparatus 10 is performed by the first electrode 11a group and the second electrode 11b group described above. The third electrode 12a group and the fourth electrode 12b group can be the same.

  Using the detection unit 200 as described above, similarly to the above, the first measurement for measuring the capacitance of each of the first detection unit 211 and the second detection unit 212, and between the first detection unit 211 and the second detection unit 212. A second measurement is performed to measure the electrostatic capacity of. The dielectric constant of the measurement target substance existing in the vicinity of the gap between the first detection unit 211 and the second detection unit 212 is corrected for the influence of the gap that may exist in the vicinity of the surfaces of the first detection unit 211 and the second detection unit 212. Thus, it can be measured appropriately.

  The processing function of the dielectric constant measuring apparatus 10 as described above can be realized using a computer. Examples of the processing function include application of an alternating voltage signal from the applied voltage signal source 13, detection of a current value by the current detection circuit 14, switching of the switch 15a and the switch 15b of the measurement mode switching unit 15. In addition, calculation processing such as relative permittivity by the calculation unit 17 using the detected current value and data stored in the memory 18 (distribution data, constants, division conditions of the relative permittivity range, etc.), writing to the memory 18 Or read-out etc. are mentioned.

FIG. 15 is a diagram illustrating a configuration example of computer hardware used in the dielectric constant measuring apparatus.
The computer 500 used in the dielectric constant measuring apparatus 10 is controlled by the processor 501 as a whole. The processor 501 is connected to a RAM (Random Access Memory) 502 and a plurality of peripheral devices via a bus 509. The processor 501 may be a multiprocessor. The processor 501 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a programmable logic device (PLD). The processor 501 may be a combination of two or more of CPU, MPU, DSP, ASIC, and PLD.

  The RAM 502 is used as a main storage device of the computer 500. The RAM 502 temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the processor 501. The RAM 502 stores various data necessary for processing by the processor 501.

  Peripheral devices connected to the bus 509 include an HDD (Hard Disk Drive) 503, a graphic processing device 504, an input interface 505, an optical drive device 506, a device connection interface 507, and a network interface 508.

  The HDD 503 is used as an auxiliary storage device of the computer 500. The HDD 503 stores an OS program, application programs, and various data. A semiconductor storage device such as a flash memory can be used as the auxiliary storage device.

  A monitor 511 such as a display device using a CRT (Cathode Ray Tube) or a liquid crystal display device is connected to the graphic processing device 504. The graphic processing device 504 displays an image on the screen of the monitor 511 in accordance with an instruction from the processor 501.

  A keyboard 512 and a mouse 513 are connected to the input interface 505. The input interface 505 transmits a signal transmitted from the keyboard 512 or the mouse 513 to the processor 501. Note that the mouse 513 is an example of a pointing device, and other pointing devices can also be used. Examples of other pointing devices include a touch panel, a tablet, a touch pad, and a trackball.

  The optical drive device 506 reads data recorded on the optical disk 514 using laser light or the like. The optical disk 514 is a portable recording medium on which data is recorded so that it can be read by reflection of light. The optical disk 514 includes a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc Read Only Memory), a CD-R (Recordable) / RW (ReWritable), and the like.

  The device connection interface 507 is a communication interface for connecting peripheral devices to the computer 500. For example, a memory device 515 or a memory reader / writer 516 can be connected to the device connection interface 507. The memory device 515 is a recording medium equipped with a communication function with the device connection interface 507. The memory reader / writer 516 is a device that writes data to the memory card 517 or reads data from the memory card 517. The memory card 517 is a card type recording medium.

  The network interface 508 is connected to the network 510. The network interface 508 transmits and receives data to and from other computers or communication devices via the network 510.

With the hardware configuration as described above, the processing function of the dielectric constant measuring apparatus 10 can be realized.
The computer 500 implements the processing function of the dielectric constant measuring apparatus 10 by executing a program recorded on a computer-readable recording medium, for example. A program describing the processing contents to be executed by the computer 500 can be recorded in various recording media. For example, a program to be executed by the computer 500 can be stored in the HDD 503. The processor 501 loads at least a part of the program in the HDD 503 into the RAM 502 and executes the program. In addition, a program to be executed by the computer 500 can be recorded on a portable recording medium such as the optical disk 514, the memory device 515, and the memory card 517. The program stored in the portable recording medium can be executed after being installed in the HDD 503 under the control of the processor 501, for example. Further, the processor 501 can also read and execute the program directly from the portable recording medium.

Regarding the embodiment described above, the following additional notes are further disclosed.
(Supplementary Note 1) a first detection unit including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A dielectric constant measurement apparatus comprising: a switching unit that switches between a second measurement mode for measuring a third capacitance between the first detection unit and the second detection unit.

(Supplementary Note 2) In the first measurement mode, the first static mode is based on a first current value detected from the second electrode and the fourth electrode by applying a voltage to the first electrode and the third electrode. A measurement mode for measuring a sum of a capacitance and the second capacitance,
In the second measurement mode, the third capacitance is measured based on a second current value detected from the third electrode and the fourth electrode by applying a voltage to the first electrode and the second electrode. The dielectric constant measuring apparatus according to appendix 1, wherein the dielectric constant measuring apparatus is in a measurement mode.

(Supplementary Note 3) A detection unit that detects the first current value and the second current value;
The sum of the first capacitance and the second capacitance is calculated based on the detected first current value, and the third capacitance is calculated based on the detected second current value The dielectric constant measuring device according to claim 2, further comprising:

  (Additional remark 4) The said calculating part uses the sum of the said 1st electrostatic capacitance measured and the said 2nd electrostatic capacitance, and the said 3rd electrostatic capacitance, and the said 1st detection part and the said 2nd detection part The dielectric constant measuring apparatus according to supplementary note 3, wherein the dielectric constant of a measurement target substance is calculated.

(Additional remark 5) The storage part in which the information regarding the 1st signal corresponding to the sum of the said 1st electrostatic capacitance and the said 2nd electrostatic capacitance and the 2nd signal corresponding to the said 3rd electrostatic capacitance was stored was included. ,
The dielectric constant measuring apparatus according to appendix 4, wherein the computing unit computes a dielectric constant of the measurement target substance using the information.

(Additional remark 6) The said information is 1st data which shows the relationship between the said 1st signal and the said 2nd signal when there is no clearance gap between the said 1st detection part and the said 2nd detection part, and the said measurement object substance. And second data indicating a relationship between the first signal and the second signal when there is a gap between the first detection unit and the second detection unit and the measurement target substance,
The calculation unit compares the measured first capacitance and the second capacitance and the third capacitance with the first data and the second data, and the measurement target substance. The dielectric constant measuring apparatus according to appendix 5, wherein the dielectric constant is calculated.

(Appendix 7) The information is
A first linear function indicating a relationship between the first signal and the second signal when there is no gap between the first detection unit and the second detection unit and the measurement target substance;
A second linear function indicating the relationship between the second signal and the dielectric constant of the substance to be measured;
A ratio of a rate of change of the second signal and a rate of change of the first signal when the dielectric constant of the measurement target substance is constant and the thickness of the gap changes,
The computing unit is
Obtaining a third linear function using the sum of the first capacitance and the second capacitance to be measured, the third capacitance, and the ratio;
Obtaining a value of the second signal at the intersection of the third linear function and the first linear function;
The dielectric constant measuring apparatus according to claim 5, further comprising: calculating a dielectric constant of the measurement target substance using the value and the second linear function.

(Additional remark 8) The distance between the said 1st electrode and the said 2nd electrode, and the distance between the said 3rd electrode and the said 4th electrode are the distance between the said 1st detection part and the said 2nd detection part. The first electrode and the second electrode are arranged in parallel, and the third electrode and the fourth electrode are arranged in parallel, so that the first electrode and the second electrode are arranged in parallel. Dielectric constant measuring device.

(Supplementary Note 9) a first detection unit including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A dielectric constant measuring method using a dielectric constant measuring apparatus including: a switching unit that switches between a first measurement unit and a second measurement mode for measuring a third capacitance between the second detection unit,
Arranging the first detection unit and the second detection unit across a substance to be measured; and
Switching to the first measurement mode by the switching unit and measuring the sum of the first capacitance and the second capacitance;
And a step of setting the second measurement mode by the switching unit and measuring the third capacitance.

(Additional remark 10) The process of calculating the dielectric constant of the said measuring object substance by the said dielectric constant measuring apparatus using the sum of said 1st electrostatic capacitance and said 2nd electrostatic capacitance, and said 3rd electrostatic capacitance. The dielectric constant measuring method according to appendix 9, characterized by comprising:

(Additional remark 11) The 1st detection part containing a 1st electrode and a 2nd electrode,
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A dielectric constant measurement program for measuring a dielectric constant using a dielectric constant measurement device including a switching unit that switches between a first measurement unit and a second measurement mode for measuring a third capacitance between the second detection unit and a second measurement mode. And
On the computer,
The first electrostatic mode between the first electrode and the second electrode of the first detection unit and the second detection unit, which are arranged in the first measurement mode by the switching unit and sandwich the substance to be measured. Measuring the sum of the capacitance and the second capacitance between the third electrode and the fourth electrode;
The second measurement mode is set by the switching unit, and the process of measuring the third capacitance between the first detection unit and the second detection unit arranged with the measurement target substance interposed therebetween is executed. Characteristic permittivity measurement program.

  (Additional remark 12) Let the said computer perform the process which calculates the dielectric constant of the said measuring object substance using the sum of said 1st electrostatic capacitance and said 2nd electrostatic capacitance, and said 3rd electrostatic capacitance. The dielectric constant measurement program according to appendix 11, characterized by:

DESCRIPTION OF SYMBOLS 10 Dielectric constant measuring apparatus 11, 211 1st detection part 11a, 211a 1st electrode 11b, 211b 2nd electrode 11c, 12c Main body 12,212 2nd detection part 12a, 212a 3rd electrode 12b, 212b 4th electrode 13 Applied voltage Signal source 14 Current detection circuit 15 Measurement mode switching unit 15a, 15b Switch 16 Control unit 17 Calculation unit 18 Memory 20, 100 Measurement target substance 31, 32, 33 Electric field 41, 42 Gap 70 Distribution data 80 Model 101, 102, 201 Electrode DESCRIPTION OF SYMBOLS 103 Detection unit 200 Detection part 202 Cylinder 500 Computer 501 Processor 502 RAM
503 HDD
504 Graphic processing device 505 Input interface 506 Optical drive device 507 Device connection interface 508 Network interface 509 Bus 510 Network 511 Monitor 512 Keyboard 513 Mouse 514 Optical disk 515 Memory device 516 Memory reader / writer 517 Memory card

Claims (8)

A first detector including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A switching unit for switching between a second measurement mode for measuring a third capacitance between the first detection unit and the second detection unit;
A storage unit storing information related to a first signal corresponding to a sum of the first capacitance and the second capacitance, and a second signal corresponding to the third capacitance;
Using the sum of the first capacitance and the second capacitance , the third capacitance, and the information, the measurement target substance provided between the first detection unit and the second detection unit only contains a calculator for calculating the dielectric constant,
The information includes first data indicating a relationship between the first signal and the second signal when there is no gap between the first detection unit and the second detection unit and the measurement target substance, and the first data Including second data indicating a relationship between the first signal and the second signal when there is a gap between the first detection unit and the second detection unit and the measurement target substance,
The calculation unit compares the measured first capacitance and the second capacitance and the third capacitance with the first data and the second data, and the measurement target substance. A dielectric constant measuring apparatus for calculating a dielectric constant of a dielectric constant. A first detector including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A switching unit for switching between a second measurement mode for measuring a third capacitance between the first detection unit and the second detection unit;
A storage unit storing information related to a first signal corresponding to a sum of the first capacitance and the second capacitance, and a second signal corresponding to the third capacitance;
Using the sum of the first capacitance and the second capacitance , the third capacitance, and the information, the measurement target substance provided between the first detection unit and the second detection unit only contains a calculator for calculating the dielectric constant,
The information is
A first linear function indicating a relationship between the first signal and the second signal when there is no gap between the first detection unit and the second detection unit and the measurement target substance;
A second linear function indicating the relationship between the second signal and the dielectric constant of the substance to be measured;
The ratio of the change rate of the second signal and the change rate of the first signal when the dielectric constant of the measurement target substance is constant and the thickness of the gap changes.
Including
The computing unit is
Using the sum of the first capacitance and the second capacitance to be measured, the third capacitance, and the ratio, obtain a third linear function,
Obtaining the value of the second signal at the intersection of the third linear function and the first linear function;
A dielectric constant measuring apparatus that calculates a dielectric constant of the substance to be measured using the value and the second linear function . In the first measurement mode, based on a first current value detected from the second electrode and the fourth electrode by applying a voltage to the first electrode and the third electrode, the first capacitance and the third electrode It is a measurement mode for measuring the sum with the second capacitance,
In the second measurement mode, the third capacitance is measured based on a second current value detected from the third electrode and the fourth electrode by applying a voltage to the first electrode and the second electrode. it is a measurement mode for the dielectric constant measuring apparatus according to claim 1 or 2, characterized in. A detector for detecting the first current value and the second current value;
The calculation unit calculates a sum of the first capacitance and the second capacitance based on the first current value detected by the detection unit, and the second detection unit detects the second capacitance detected by the detection unit. The dielectric constant measuring apparatus according to claim 3 , wherein the third capacitance is calculated based on a current value. The first detection unit includes a plurality of first electrodes and a plurality of second electrodes arranged alternately,
The second detecting unit has a dielectric constant measuring apparatus according to any one of claims 1 to 4, characterized in that it comprises a plurality of the third electrodes and the plurality of the fourth electrodes alternately arranged. A first detector including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A switching unit for switching between a second measurement mode for measuring a third capacitance between the first detection unit and the second detection unit;
A storage unit storing information related to a first signal corresponding to a sum of the first capacitance and the second capacitance, and a second signal corresponding to the third capacitance;
Using the sum of the first capacitance and the second capacitance, the third capacitance, and the information, the measurement target substance provided between the first detection unit and the second detection unit only contains a calculator for calculating the dielectric constant,
The information includes first data indicating a relationship between the first signal and the second signal when there is no gap between the first detection unit and the second detection unit and the measurement target substance, and the first data A dielectric constant measuring apparatus including a first data and a second data indicating a relationship between the first signal and the second signal when there is a gap between the first detection unit and the second detection unit and the measurement target substance is used. A dielectric constant measurement method,
Arranging the first detection unit and the second detection unit so that the substance to be measured is provided between the first detection unit and the second detection unit;
Switching to the first measurement mode by the switching unit and measuring the sum of the first capacitance and the second capacitance;
Setting the second measurement mode by the switching unit and measuring the third capacitance;
The measuring unit compares the sum of the first capacitance and the second capacitance measured by the calculation unit and the third capacitance with the first data and the second data. A method for measuring a dielectric constant, comprising: calculating a dielectric constant of the dielectric constant. A first detector including a first electrode and a second electrode;
A second detector including a third electrode and a fourth electrode;
A first measurement mode for measuring a sum of a first capacitance between the first electrode and the second electrode and a second capacitance between the third electrode and the fourth electrode; A switching unit for switching between a second measurement mode for measuring a third capacitance between the first detection unit and the second detection unit;
A storage unit storing information related to a first signal corresponding to a sum of the first capacitance and the second capacitance, and a second signal corresponding to the third capacitance;
Using the sum of the first capacitance and the second capacitance, the third capacitance, and the information, the measurement target substance provided between the first detection unit and the second detection unit only contains a calculator for calculating the dielectric constant,
The information is
A first linear function indicating a relationship between the first signal and the second signal when there is no gap between the first detection unit and the second detection unit and the measurement target substance;
A second linear function indicating the relationship between the second signal and the dielectric constant of the substance to be measured;
Dielectric constant measurement using a dielectric constant measuring apparatus including a ratio of a change rate of the second signal and a change rate of the first signal when the dielectric constant of the measurement target substance is constant and the thickness of the gap changes. A method,
Arranging the first detection unit and the second detection unit so that the substance to be measured is provided between the first detection unit and the second detection unit;
Switching to the first measurement mode by the switching unit and measuring the sum of the first capacitance and the second capacitance;
Setting the second measurement mode by the switching unit and measuring the third capacitance;
Obtaining a third linear function by using the sum of the first capacitance and the second capacitance measured, the third capacitance, and the ratio by the arithmetic unit; ,
Obtaining a value of the second signal at the intersection of the third linear function and the first linear function by the arithmetic unit;
A dielectric constant measurement method comprising: calculating a dielectric constant of the measurement target substance by using the value and the second linear function by the calculation unit . The first detection unit includes a plurality of first electrodes and a plurality of second electrodes arranged alternately,
The dielectric constant measurement method according to claim 6 or 7 , wherein the second detection unit includes a plurality of the third electrodes and a plurality of the fourth electrodes arranged alternately.

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