Measurement method, measurement system, and program

Abstract

Impedance is measured by applying a predetermined voltage to an object to be measured via a measurement unit that includes an electrode having a predetermined shape and a substrate on the surface of which the electrode is formed, and the measurement result is input to a predetermined calculation formula defined on the basis of an equivalent circuit corresponding to the configuration of the measurement unit and the object to be measured. The equivalent circuit corresponds to an electric field between the electrodes in the measurement unit, an electric field on the substrate side of the electrodes, and an electric field on the measurement target side of the electrodes, and the predetermined calculation formula includes parameters based on a measurement result of the standard sample and a measurement result of the background sample by the measurement unit.

Description

Technical Field

[0001] The present invention relates to a measuring method, a measuring system and a program. Background Art

[0002] In the past, in mechanical devices such as bearing devices and sliding devices, it is widely used to lubricate the contact surfaces between components using lubricants (such as lubricating oil and grease). On the other hand, for such mechanical devices, by monitoring the lubrication status, damage and wear can be detected in advance to suppress the occurrence of failures of rotating components.

[0003] In a mechanical device using a lubricant, in order to measure its lubrication state, it is required to appropriately measure the internal state. As one of the methods for detecting the state of the lubricant, there is a method using impedance analysis based on an AC power supply. By using impedance analysis, the electrical properties of the material can be derived. For example, Patent Document 1 discloses a method that can easily diagnose the state of the lubricant without destroying the object of diagnosis.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 7136378 Summary of the invention

[0007] Technical problem that the invention aims to solve

[0008] Patent document 1 shows a structure using impedance analysis using parallel plate electrodes. On the other hand, depending on the location where the lubrication state is monitored, it is sometimes different from the state of the parallel plate. In addition, it is also assumed that the sample of the object of the measurement state is a very small amount. Therefore, a measurement method for samples that can also cope with such conditions is sought.

[0009] In view of the above problems, an object of the present invention is to provide a method capable of measuring the state of a trace amount of a sample with high accuracy.

[0010] Technical solutions to the problem

[0011] In order to solve the above problems, the present invention has the following structure. That is, a determination method, comprising:

[0012] a measuring step of measuring impedance by applying a predetermined voltage to the object to be measured via a measuring unit, the measuring unit including an electrode of a predetermined shape and a substrate having the electrode formed on a surface thereof; and

[0013] a deriving step of inputting the measurement result of the measuring step into a predetermined calculation formula defined based on an equivalent circuit corresponding to the structure of the measuring section and the measurement object, thereby deriving the complex dielectric constant of the measurement object,

[0014] The equivalent circuit is defined to correspond to the electric field between the electrodes in the measurement unit, the electric field on the substrate side of the electrodes, and the electric field on the measurement object side of the electrodes.

[0015] The defined calculation formula is defined to include parameters based on the measurement results of the standard specimen and the background specimen by the measurement unit.

[0016] In addition, another aspect of the present invention has the following structure. That is, a measurement system includes:

[0017] A measurement unit including electrodes having a specified shape and a substrate on the surface of which the electrodes are formed;

[0018] A power supply unit that supplies a specified voltage;

[0019] A measurement unit that applies a specified voltage from the power supply unit to a measurement object via the measurement unit to measure impedance; and

[0020] A derivation unit that inputs the measurement result of the measurement unit into a specified calculation formula defined based on an equivalent circuit corresponding to the structure of the measurement unit and the measurement object, thereby deriving the complex dielectric constant of the measurement object.

[0021] The equivalent circuit is defined to correspond to the electric field between the electrodes in the measurement unit, the electric field on the substrate side of the electrodes, and the electric field on the measurement object side of the electrodes.

[0022] The defined calculation formula is defined to include parameters based on the measurement results of the standard specimen and the background specimen by the measurement unit.

[0023] In addition, another aspect of the present invention has the following structure. That is, a program characterized in that

[0024] Causes a computer to execute the following steps:

[0025] A measurement step of applying a specified voltage to a measurement object via a measurement unit to measure impedance, the measurement unit including electrodes having a specified shape and a substrate on the surface of which the electrodes are formed; and

[0026] A derivation step of inputting the measurement result of the measurement step into a specified calculation formula defined based on an equivalent circuit corresponding to the structure of the measurement unit and the measurement object, thereby deriving the complex dielectric constant of the measurement object.

[0027] The equivalent circuit is defined to correspond to the electric field between the electrodes in the measurement unit, the electric field on the substrate side of the electrodes, and the electric field on the measurement object side of the electrodes.

[0028] The specified calculation formula is specified to include parameters based on the measurement results of the standard specimen and the measurement results of the background specimen by the measurement unit.

[0029] Advantages of the Invention

[0030] According to the present invention, a method capable of accurately measuring the state of a trace specimen can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram showing a structural example of an electrode portion composed of a parallel plate electrode and a comb-shaped electrode.

[0032] Figure 2 It is a schematic diagram showing a configuration example of an electrode portion according to an embodiment of the present invention.

[0033] Figure 3 It is a diagram for explaining an equivalent circuit of an electrode portion according to an embodiment of the present invention.

[0034] Figure 4 It is a diagram showing an example of measurement results of an electrode portion based on a parallel plate electrode and a comb-shaped electrode (before improvement).

[0035] Figure 5 It is a diagram for explaining an equivalent circuit of an electrode portion according to an embodiment of the present invention.

[0036] Figure 6 It is a diagram for explaining an equivalent circuit of an electrode portion according to an embodiment of the present invention.

[0037] Figure 7 It is a diagram showing an example of measurement results of an electrode portion based on a parallel plate electrode and a comb-shaped electrode (after improvement).

[0038] Figure 8 It is a diagram showing an example of measurement results of an electrode portion of a comb-shaped electrode (after improvement) of the present invention.

[0039] Figure 9 It is a diagram showing an application example of a measurement device of a comb-shaped electrode of the present invention.

[0040] Figure 10 It is a flowchart of a measurement process according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, the mode for implementing the present invention will be described with reference to the accompanying drawings and the like. In addition, the embodiment described below is used to illustrate one embodiment of the present invention and is not intended to limit the interpretation of the present invention. In addition, all structures described in each embodiment are not limited to structures necessary to solve the problems of the present invention. In addition, in each of the drawings, the same constituent elements are indicated by marking the same reference numerals to indicate the corresponding relationship.

[0042] <First Embodiment>

[0043] Hereinafter, a first embodiment of the present invention will be described.

[0044] [Example of electrode structure]

[0045] First, the electrode configuration used for measuring the lubrication state of the lubricant according to the present embodiment will be described. In the present embodiment, the lubricant as an example of a sample to be measured includes lubricating oil, grease, etc., but is not particularly limited.

[0046] Figure 1 This is a schematic diagram showing the configuration of an electrode unit and an AC power source when evaluating (measuring) the electrical characteristics of a lubricant. Figure 1 (a) shows a schematic structure of an electrode unit 100 (hereinafter also referred to as a "parallel plate electrode") using a parallel plate in a conventional structure during measurement. The electrode unit 100 applies power to a lubricant 103 (e.g., block grease) filled between parallel plate electrodes 101 and 102 through an AC power supply 200. The distance between the parallel plate electrodes 101 and 102 can be configured to be, for example, mm-level.

[0047] on the other hand, Figure 1 (b) shows a schematic structure of the measurement using the measurement unit 300 of this embodiment. In the measurement unit 300, two comb-shaped electrodes 301 and 302 are formed on a substrate 303, and power is applied to them by an AC power supply 200. The teeth of the two comb-shaped electrodes 301 and 302 are configured to mesh with each other, and a more specific structural example of the comb-shaped electrodes will be described later.

[0048] Figure 2 FIG. 2 is a schematic diagram showing an enlarged view of the periphery of the teeth 301a and 302a of the comb-shaped electrodes 301 and 302 in the measuring unit 300 of the present embodiment. Figure 1 As shown in (b), the comb-shaped electrode 301 and the comb-shaped electrode 302 are configured to mesh with each other so that the teeth 301a and the teeth 302a are alternately arranged. Figure 2As shown in (a) of [reference], the comb-shaped electrodes 301 and 302 can be made of, for example, Au (gold), and the substrate 303 can be made of SiO2 (silicon dioxide). In addition, the comb-shaped electrodes 301 and 302 each include a plurality of teeth, and for example, the number thereof can be 66 each, that is, a total of 132 teeth. Further, the size of the teeth can be set such that the height is 0.1 μm and the length is 4.0 mm. In addition, the teeth 301a of the comb-shaped electrode 301 and the teeth 302a of the comb-shaped electrode 302 can be arranged parallel to each other along Figure 2 the depth direction in [reference], and the interval can be 5.0 μm. In addition, the size of the above-described measurement unit 300 is an example and is not limited thereto.

[0049] Figure 2 (b) of [reference] shows a state in which the lubricant 400 to be measured is dropped onto the measurement unit 300. In the present embodiment, it is assumed that a case where the amount of the lubricant 400 is less than 10 mg can be dealt with, which is about 1 / 1000 of the amount measured by the measurement device having the electrode unit 100 of the parallel plate as shown in (a) of [reference]. Figure 1 (a) of [reference] shows a schematic diagram of the measurement unit 300 shown in (a) of [reference] simplified, in which the teeth of the comb-shaped electrodes 301 and 302 are respectively aggregated into one. In (a) of [reference], the dotted line indicates the electric field when an alternating current is applied. In addition,

[0050] Figure 3 (a) of [reference] is a schematic diagram of the figure simplifying the measurement unit 300 shown in (a) of [reference], in which the teeth of the comb-shaped electrodes 301 and 302 are respectively aggregated into one. In Figure 2 (a) of [reference], the dotted line indicates the electric field when an alternating current is applied. In addition, Figure 3 (b) of [reference] shows an equivalent circuit electrically equivalent to the structure shown in (a) of [reference]. Figure 3 (b) of [reference] shows an equivalent circuit electrically equivalent to the structure shown in (a) of [reference]. Figure 3 (a) of [reference].

[0051] Figure 3 (b) of [reference] shows an equivalent circuit having a structure in which a capacitor C made of a lubricant and a resistor R caused by elements around it are connected in parallel. In addition, the impedance of the circuit E is represented by Z. Here, the alternating voltage V applied to the circuit E, the current I flowing through the circuit E, and the complex impedance Z of the entire circuit E are represented by the following formulas (1) to (3).

[0052] V = |V|exp(jωt)…(1)

[0053] I = |I|exp(j(ωt - θ))…(2)

[0054] Z = V / I = |V / I|exp(jθ) = |Z|exp(jθ)…(3)

[0055] j: imaginary number

[0056] ω: angular frequency of the voltage

[0057] t: time

[0058] θ: Phase angle (offset between the phases of voltage and current)

[0059] Moreover, in the equivalent circuit, the complex dielectric constant (ε r ’ and ε r ”) can be derived from the distance and electrode area between the comb-shaped electrodes 301 and 302.

[0060] [Pre-verification]

[0061] Next, on the premise of the equivalent circuit shown in Figure 3 , the inventors of the present application conducted pre-verification on a measurement device using parallel plate electrodes and a measurement device using comb-shaped electrodes as conventional structures, and presented the verification results. In addition, for example, the measurement device using parallel plate electrodes shown in Patent Document 1 can achieve high measurement accuracy.

[0062] Figure 4 Represents the complex dielectric constant (ε r ’, ε r ”) obtained from the measurement results of a measurement device using parallel plate electrodes as an existing structure and a measurement device using comb-shaped electrodes. In Figure 4 (a), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis is a semi-logarithmic curve representing the real part ε r ’ of the complex dielectric constant. Plot 401 represents the measurement result of the measurement device using comb-shaped electrodes, and plot 402 represents the measurement result of the measurement device using parallel plate electrodes.

[0063] In addition, in Figure 4 (b), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis is a semi-logarithmic curve representing the imaginary part ε r ” of the complex dielectric constant. Plot 411 represents the measurement result of the measurement device using comb-shaped electrodes, and plot 412 represents the measurement result of the measurement device using parallel plate electrodes.

[0064] As shown in Figure 4 (a) and (b), there is a deviation between the measurement results of the measurement device using parallel plate electrodes and the measurement device using comb-shaped electrodes. That is, it is determined that the measurement accuracy of the measurement device using comb-shaped electrodes is lower than that of the measurement device using parallel plate electrodes. The inventors of the present application conducted experiments and research on the main reasons, and as a result, it was determined that the main reason lies in the derivation of the complex dielectric constant (ε Figure 3 ’ and ε r ’, ε r ”) based on the equivalent circuit shown in

[0065] [Equivalent circuit]

[0066] Hereinafter, the derivation of the complex dielectric constant by using the measurement apparatus with the comb-shaped electrodes of the present embodiment will be described. In Figure 3 the example of (a) of

[0067] Figure 5 only the direct electric field is assumed between the teeth of the comb-shaped electrodes. On the other hand, in the measurement apparatus using the comb-shaped electrodes of the present embodiment, the electric field surrounding the electrodes is further considered. That is, focusing on the case where the distance between the electrodes is long relative to the electrode area (thickness of the gold evaporation film) of the comb-shaped electrodes, the surrounding of this electric field is considered. Figure 2 Figure (a) of Figure 5 is a schematic diagram in which the teeth of the comb-shaped electrodes 301 and 302 are respectively aggregated into one by simplifying the diagram of the measurement unit 300 shown in (a) of

[0068] In addition, Figure 5 Figure (b) of Figure 5 represents an equivalent circuit of an improved electrical equivalence based on the structure shown in (a) of

[0069] Figure 5 The equivalent circuit shown in (b) of

[0070] has a structure of a circuit in which parallel circuits each formed by connecting a capacitor C and a resistor R corresponding to the above three electric fields (regions) in parallel are connected in parallel. An alternating current of an alternating power supply is applied to this equivalent circuit. Figure 5 Furthermore, in the present embodiment, based on the structure shown in tol a calculation formula for deriving the complex dielectric constant is defined. In order to derive the dielectric constant ε of the lubricant (specimen) to be measured, in the present embodiment, the dielectric constant ε air of the standard specimen (here, toluene) and the dielectric constant ε

[0071] Figure 6 Figure (a) of Figure 5 represents the state where the specimen 601 is disposed in the measurement unit 300 in the schematic structure shown in (a) of

[0072] Figure 6 In (b), it is equivalent to the state where the specimen 601 is not disposed in the measurement unit 300 in the schematic structure shown in (a) of Figure 5 , that is, the state where the air 602 of the specimen as the background (hereinafter also referred to as "background specimen") exists at the measurement position. At this time, the dielectric constant ε of the air 602 air is known.

[0073] Figure 6 (c) represents the state where the standard specimen 603 is disposed in the measurement unit 300 in the schematic structure shown in (a) of Figure 5 . At this time, the dielectric constant ε of the standard specimen 603 tol and the conductivity σ tol are known.

[0074] First, Figure 6 the complex admittance Y of the entire equivalent circuit shown in (b) of * can be expressed as in the following formula (4).

[0075] [Equation 1]

[0076] Y * = Y e * + Y i * + Y b * …(4)

[0077] Y * : The complex admittance of the entire equivalent circuit of the comb-shaped electrode

[0078] Y e * : The complex admittance of the equivalent circuit corresponding to the upper-side electric field

[0079] Y i * : The complex admittance of the equivalent circuit corresponding to the inter-electrode electric field

[0080] Y b * : The complex admittance of the equivalent circuit corresponding to the substrate-side electric field

[0081] The complex admittance Y e * 、Y i * 、Y b * can be respectively expressed as in the following formulas (5) to (7) using the imaginary unit j.

[0082] In addition, S in the following formulas b / d b 、Si / d i 、S e / d e are the reciprocals of the equivalent unit constants of the substrate, between the electrodes, and above the electrodes, respectively, and they are equivalent to Figure 1 the electrode area / electrode distance in the case of the parallel plate electrodes shown in (a) of

[0083] [Number 2]

[0084]

[0085] j: imaginary number

[0086] ω: angular frequency of the voltage

[0087] R e : resistance of the substance existing above the electrodes

[0088] R i : resistance of the substance existing between the electrodes

[0089] R b : resistance of the substrate

[0090] C e : capacitance of the substance existing above the electrodes

[0091] C i : capacitance of the substance existing between the electrodes

[0092] C b : capacitance of the substrate

[0093] S e : electrode area corresponding to the upper side electric field

[0094] S i : electrode area corresponding to the electric field between the electrodes

[0095] S b : electrode area corresponding to the substrate side electric field

[0096] d e : distance between the electrodes corresponding to the upper side electric field

[0097] d i : distance between the electrodes corresponding to the electric field between the electrodes

[0098] d b : distance between the electrodes corresponding to the substrate side electric field

[0099] σ e : conductivity existing above the electrodes

[0100] σ i: Conductivity of the substance existing between the electrodes

[0101] σ b : Conductivity of the substrate

[0102] ε e : Dielectric constant of the substance existing above the electrodes

[0103] ε i : Dielectric constant of the substance existing between the electrodes

[0104] ε b : Dielectric constant of the substrate

[0105] Based on Equations (4) to (7), the complex admittance Y of the entire equivalent circuit of the comb-shaped electrodes * is represented by the following Equation (8).

[0106] [Equation 3]

[0107]

[0108] Here, the complex admittance Y of the entire equivalent circuit of the comb-shaped electrodes * is defined by the following Expression (9).

[0109] [Equation 4]

[0110] Y * = Y'+ jY"…(9)

[0111] Then, by comparing the real and imaginary parts shown in Equation (8) and Equation (9), the following Equation (10) and Equation (11) are obtained.

[0112] [Equation 5]

[0113]

[0114] In Figure 6 the measurement condition shown in (a), the imaginary part Y" of the complex admittance during the measurement of the specimen 601 SPL According to the relationship of ε i = ε e = ε, ε b = ε SiO2 and the above (11), is represented by the following Equation (12).

[0115] [Equation 6]

[0116]

[0117] Y" SPL : Imaginary part of the complex admittance of the specimen

[0118] ε SiO2 : Dielectric constant of the substrate (SiO2)

[0119] Here, ε shown in formula (12), SiO2 , S b / d b , (S i / d i +S e / d e ) are values that vary according to the manufacturing precision of the electrodes. Therefore, in the present embodiment, they are eliminated. In the Figure 6 measurement (background: air) shown in (b), the imaginary part Y" of the complex admittance of the background sample, i.e., air BK According to the relationship of ε i = ε e = ε air , ε b = ε SiO2 and the above (11), it is expressed by the following formula (13).

[0120] [Equation 7]

[0121]

[0122] Y" BK : Imaginary part of the complex admittance of the background sample (air)

[0123] ε air : Dielectric constant of the background sample (air)

[0124] In addition, in the case of the measurement (standard sample: toluene) shown in Figure 6 (c), the imaginary part Y" of the complex admittance of the standard sample, i.e., toluene STD , according to the relationship of ε i = ε e = ε tol and ε b = ε SiO2 and the above (11), it is expressed by the following formula (14).

[0125] [Equation 8]

[0126]

[0127] Y" STD : Imaginary part of the complex admittance of the standard sample (toluene)

[0128] ε tol : Dielectric constant of the standard sample (toluene)

[0129] Then, based on formulas (12) to (14), calculations are performed as shown in the following formulas (15) to (17). If sorted by ε, it can be expressed as formula (18).

[0130] [Number 9]

[0131]

[0132] [Number 10]

[0133]

[0134] In addition, ε used in the above formula (18) is equivalent to the real part component ε’ of the complex dielectric constant ε, and thus the following formula (19) is obtained. * of the complex dielectric constant ε, and thus the following formula (19) is obtained.

[0135] [Number 11]

[0136]

[0137] ε’: the real part component of the complex dielectric constant ε * of the complex dielectric constant ε

[0138] Similarly, in the measurement situation shown in (a) of Figure 6 the real part Y’ of the complex admittance during the measurement of the specimen 601 SPL is represented by the following formula (20) through the relationship of σ i = σ e = σ, σ b = σ SiO2 and the above formula (10).

[0139] [Number 12]

[0140]

[0141] Y’ SPL : the real part of the complex admittance of the specimen

[0142] σ SiO2 : the conductivity of the substrate (SiO2)

[0143] In Figure 6 the measurement situation shown in (b) of BK (background: air), the real part Y’ of the complex admittance of the background, i.e., air i is represented by the following formula (21) through the relationship of σ e = σ air , σ b = σ SiO2 and the above formula (10).

[0144] [Number 13]

[0145]

[0146] Y’ BK : the real part of the complex admittance of the background (air)

[0147] σ air : Conductivity of the background (air)

[0148] In addition, in the case of the measurement as shown in Figure 6 (c) (Standard sample: toluene), the real part Y' of the complex admittance of the standard sample, i.e., toluene STD , through σ i = σ e = σ tol and σ b = σ SiO2 and the above expression (10), is represented by the following expression (22).

[0149] [Equation 14]

[0150]

[0151] Y' STD : Real part of the complex admittance of the standard sample (toluene)

[0152] σ tol : Conductivity of the standard sample (toluene)

[0153] Moreover, if calculated as in the following equations (23) and (24) based on equations (15), (20) - (22) and arranged in terms of σ / ω, it can be expressed as in equation (25).

[0154] [Equation 15]

[0155]

[0156] [Equation 16]

[0157]

[0158] In addition, σ / ω used in the above equation (25) corresponds to the imaginary part component ε * '' of the complex dielectric constant ε, so the following equation (26) is obtained.

[0159] [Equation 17]

[0160]

[0161] ε'': Imaginary part component of the complex dielectric constant ε *

[0162] When performing these measurements using an LCR meter, the following relationships shown in equations (27) and (28) are defined among the magnitude |Z| (|| represents absolute value) of the impedance as the measurement output value, the phase angle θ, Y', and Y''. ​

[0163] [Number 18]

[0164]

[0165] That is, in Y' in Formula (19) and Formula (26) SPL , Y' STD , Y' BK , the input is measured through a sample ( Figure 6 of (a)), background measurement ( Figure 6 of (b)), and standard sample measurement ( Figure 6 (c)) to obtain the value of cosθ / |Z|. On the other hand, in Y'' in Formula (19) and Formula (26) SPL , Y'' STD , Y'' BK , the input is measured through a sample ( Figure 6 of (a)), background measurement ( Figure 6 of (b)), and standard sample measurement ( Figure 6 (c)) to obtain the value of -sinθ / |Z|. Thus, the dielectric constant ε and conductivity σ for an unknown sample can be derived.

[0166] That is, by performing three measurements, electric field analysis is not required. In addition, in the above example, the examples of using air and toluene in background measurement and standard sample measurement are illustrated, but it is not limited thereto. As long as the values of the dielectric constant and conductivity of the background measurement and standard sample can be determined in advance, the parameters of other materials can be used.

[0167] [Measurement Results]

[0168] Figure 7 and Figure 8 are diagrams showing examples of the measurement results of this embodiment.

[0169] Figure 7 Shows the complex dielectric constant (ε r ', ε r ") obtained from the measurement results of the measurement device using parallel plate electrodes as the existing structure and the measurement device using the comb-shaped electrodes of this embodiment. In Figure 7 of (a), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis is a semi-logarithmic curve representing the real part ε r ' of the complex dielectric constant. Plot 701 shows the measurement results of the measurement device using comb-shaped electrodes, and plot 402 shows the measurement results of the measurement device using parallel plate electrodes in the same way as Figure 4 of (a).

[0170] In addition, in Figure 7In (b), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis represents the imaginary part ε of the complex dielectric constant. r The semi-logarithmic curve of ". Plot 702 shows the measurement results of the measurement device using the comb-shaped electrode of the present embodiment, and Plot 412 is the same as Figure 4 The measurement results of the measurement device using the parallel plate electrode are shown in the same way as (b).

[0171] As Figure 7 As shown in (a) and (b), the measurement results of the measurement device using the parallel plate electrode and the measurement device using the comb-shaped electrode are approximately the same. That is, the measurement device using the comb-shaped electrode of the present embodiment can obtain the same accuracy as the measurement device using the parallel plate electrode.

[0172] Figure 8 It shows the complex dielectric constant ε obtained based on the measurement results of the new lubricant and the deteriorated lubricant in the measurement device using the comb-shaped electrode of the present embodiment. r ’, ε r ”. In Figure 8 In (a), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis represents the real part ε of the complex dielectric constant. r The semi-logarithmic curve of ’. Similar to Figure 7 In (a), Plot 701 shows the measurement results (new lubricant) of the measurement device using the comb-shaped electrode, and Plot 801 shows the measurement results (deteriorated lubricant) of the measurement device using the comb-shaped electrode.

[0173] In addition, in Figure 8 In (b), the horizontal axis represents the logarithm of the scanning frequency [Hz] of the AC power supply, and the vertical axis represents the imaginary part ε of the complex dielectric constant. r The semi-logarithmic curve of ”. Similar to Figure 7 In (b), Plot 702 shows the measurement results (new lubricant) of the measurement device using the comb-shaped electrode of the present embodiment, and Plot 802 shows the measurement results (deteriorated lubricant) of the measurement device using the comb-shaped electrode.

[0174] As Figure 8 As shown in (a) and (b), by the method of the present embodiment, in the measurement device using the comb-shaped electrode, the deterioration state of the lubricant can be determined.

[0175] As described above, in the measurement device using the comb-shaped electrode of the present embodiment, the same measurement results as those of the measurement device using the parallel plate electrode can be obtained. At this time, as described above, in the comb-shaped electrode, compared with the parallel plate electrode, a very small amount of sample (such as lubricant) can be used for measurement, and its practicality is higher than that of the parallel plate electrode.

[0176] [Application Example]

[0177] Figure 9 This is a schematic diagram showing an application example of the measurement method using the comb electrodes of the present embodiment. For example, as a measurement object, a rolling bearing lubricated with a lubricant can be cited. Also, a seal 900 that can be attached to a position inside the rolling bearing and can come into contact with the lubricant is used. As shown in (a) of Figure 9 , the comb electrodes 301 and 302 of the measurement unit 300 having the comb electrodes shown in (b) of Figure 1 are printed on the seal 900. In a state where the seal 900 is attached to the rolling bearing, the impedance is measured by applying a voltage to the comb electrodes. By inputting the detection result into the calculation formulas shown in the above formulas (19) and (26), the parameters of the rolling bearing can be obtained. Additionally, the parameters of the background measurement and the standard sample measurement can be measured in advance.

[0178] Figure 9 (b) of Figure 9 is an overall schematic diagram of a measurement system including a measurement device 920 and a measurement unit 300. In (b) of

[0179] , the lubricant 902 inside the rolling bearing 901 can be used as a measurement object, and the seal 900 printed with the measurement unit 300 can be provided. Figure 9 Also, as shown in (b) of

[0180] The measurement device 920 can be implemented, for example, by an information processing device configured to include a control device, a storage device, and an output device (not shown). The control device can be composed of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), or a dedicated circuit, etc. The storage device is composed of volatile and non-volatile storage media such as an HDD (Hard Disk Drive), a ROM (ReadOnly Memory), and a RAM (Random Access Memory), and can input and output various information according to instructions from the control device. The output device is composed of a display device such as a speaker, a lamp, or a liquid crystal display, etc., and reports to the operator according to instructions from the control device. The output method of the output device is not particularly limited. In addition, the output device can be a network interface with a communication function, or can perform an output operation by sending data to an external device (not shown) via a network (not shown).

[0181] The measurement device 920 instructs the input value of the power for applying an AC voltage V with an angular frequency ω of the AC power supply 200 to the measurement unit 300 having comb-shaped electrodes, and acquires the impedance Z and the phase angle θ as corresponding outputs (measurement values). Then, after the measurement device 920 derives a parameter representing the electrical characteristics related to the measurement object using these values, it performs an output.

[0182] [Processing flow]

[0183] Figure 10 This is a flowchart of the measurement process of the present embodiment using the above method. This process is executed by the measurement device 920, and can be implemented, for example, by a control device (not shown) provided in the measurement device 920 reading a program for implementing the process of the present embodiment from a storage device (not shown) and executing it. In addition, the derivation of parameters in the following processes can be configured to use the functions of general software to implement a part of it. In addition, when the processing flow starts, the comb-shaped electrodes of the measurement unit 300 are set at the measurement position, and for example, are in the state shown in (b) of Figure 2 as shown below.

[0184] In S1001, the measurement device 920 controls an LCR meter (not shown) so that the AC power supply 200 provided in the LCR meter supplies power of an AC voltage V with an angular frequency ω to the measurement object via the comb-shaped electrodes of the measurement unit 300. Thereby, an AC voltage V with an angular frequency ω is applied to the specimen (for example, the lubricant in a rolling bearing).

[0185] In S1002, the measurement device 920 obtains the impedance Z and the phase angle θ as the output for the input indicated in S1001. That is, the LCR meter takes the impedance Z and the phase angle θ as the measurement results of the sample for the AC voltage V with respect to the angular frequency ω as the input, and outputs them to the measurement device 920.

[0186] In S1003, the measurement device 920 obtains the measurement results of the previously performed background measurement ( Figure 6 (b)) and various parameters of the background (air in the above example). This information is previously input through measurement or the like and registered so as to be available in the measurement device 920. Alternatively, it may be configured such that the user of the measurement device 920 designates various parameters related to the background.

[0187] In S1004, the measurement device 920 obtains the measurement results of the previously performed standard sample measurement ( Figure 6 (c)) and various parameters of the standard sample (toluene in the above example). This information is previously input through measurement or the like and registered so as to be available in the measurement device 920. Alternatively, it may be configured such that the user of the measurement device 920 designates various parameters of the standard sample.

[0188] In S1005, the measurement device 920 substitutes the measurement results of the sample obtained in S1002 and the various parameters obtained in S1003 and S1004 into the above formulas (19) and (26), thereby deriving the complex dielectric constant of the sample. Then, based on the derived complex dielectric constant, the measurement device 920 derives the dielectric constant ε and the conductivity σ of the sample through the above calculation formulas.

[0189] In S1006, the measurement device 920 outputs the value obtained in S1005 as the measurement result. Then, this processing flow ends.

[0190] As described above, according to the present embodiment, it is possible to accurately measure the state of a trace amount of sample.

[0191] <Other Embodiments>

[0192] In addition, the structure of the measurement unit having the comb-shaped electrode of the present invention is not limited to the measurement of lubricants, and can be used for measuring various samples. For example, it can also be used to detect the degree of deterioration of the sample and the mixing of multiple substances as described above. In addition, it is not limited to mechanical devices only. For example, it can also be used to measure samples such as liquids collected from humans or other organisms.

[0193] In addition, in the above-described embodiments, an example is shown in which the shape of the comb-shaped electrodes, that is, the teeth of the comb-shaped electrodes are arranged opposite to each other in an engaged manner, but it is not limited thereto. For example, spiral electrodes may also be used.

[0194] In addition, in the above-described embodiments, an example is shown in which an alternating voltage is used as the applied voltage. However, it is not limited thereto, and a pulse input or a prescribed rectangular voltage may also be used. Therefore, as long as it is possible to compare with the measurement results of background measurement, standard specimen measurement, etc., the structure of the applied voltage is not particularly limited.

[0195] In addition, in the present invention, it is also possible to supply a program or application program for realizing the functions of the above-described one or more embodiments to a system or device by using a network or a storage medium, etc., and one or more processors in the computer of the system or device read and execute the processing of the program.

[0196] In addition, it may also be realized by a circuit (for example, ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array)) that realizes one or more functions.

[0197] Thus, the present invention is not limited to the above-described embodiments, and it is also the intended content of the present invention to combine the respective structures of the embodiments, and for those skilled in the art to make changes and applications based on the description in the specification and well-known techniques, which are included within the scope of the claims.

[0198] As described above, the following matters are disclosed in the present specification.

[0199] (1) A measurement method, characterized by comprising:

[0200] a measurement step (for example, S1001, S1002) of measuring an impedance by applying a prescribed voltage to a measurement object (for example, 400) via a measurement unit (for example, 300), the measurement unit including electrodes (for example, 301, 302) having a prescribed shape and a substrate (for example, 303) on which the electrodes are formed on the surface; and

[0201] a derivation step (for example, S1003, S1004, S1005) of inputting the measurement result of the measurement step into a prescribed calculation formula defined based on an equivalent circuit (for example Figure 5 of (b)) corresponding to the structure of the measurement unit and the measurement object, thereby deriving the complex dielectric constant of the measurement object,

[0202] The equivalent circuit is defined corresponding to the electric field between the electrodes (e.g., 501), the electric field on the substrate side of the electrodes (e.g., 503), and the electric field on the measurement object side of the electrodes (e.g., 502) in the measurement unit.

[0203] The defined calculation formula is defined to include parameters based on the measurement results of the standard specimen (e.g., 603) and the background specimen (e.g., 602) by the measurement unit.

[0204] With this structure, it is possible to accurately measure the state of a trace amount of specimen. In particular, it is possible to achieve the same measurement accuracy as that of parallel plate electrodes with a smaller amount.

[0205] (2) According to the measurement method described in (1), wherein

[0206] The defined calculation formula is defined as follows:

[0207] [Equation 19]

[0208]

[0209] ε’: The real part component of the complex dielectric constant ε *

[0210] ε”: The imaginary part component of the complex dielectric constant ε *

[0211] Y’ STD : The real part of the complex admittance of the standard specimen

[0212] Y" STD : The imaginary part of the complex admittance of the standard specimen

[0213] Y″ BK : The imaginary part of the background complex admittance

[0214] Y’ SPL : The real part of the complex admittance of the specimen

[0215] Y” SPL : The imaginary part of the complex admittance of the specimen

[0216] ω: The angular frequency of the voltage

[0217] σ tol : The conductivity of the standard specimen

[0218] ε air : The dielectric constant of the background specimen

[0219] ε tol : The dielectric constant of the standard specimen

[0220] ​​According to this structure, electric field analysis is not required, and it is possible to measure the electric field considering the space between the electrodes and the electric field surrounding the electrodes.

[0221] According to the measuring method described in (1), wherein,

[0222] The specified shape is a comb shape,

[0223] On the surface of the substrate, they are arranged in such a way that two comb-shaped electrodes face each other and the teeth of the combs mesh with each other.

[0224] According to this structure, by expanding the contact area with the specimen in the comb-shaped electrodes, high-precision measurement can be performed.

[0225] (4) According to the measuring method described in (1), wherein,

[0226] The measuring part is provided in a rolling bearing (for example, 901),

[0227] The object to be measured is the lubricant (for example, 902) inside the rolling bearing.

[0228] According to this structure, it is possible to use the lubricant inside the rolling bearing as the object to be measured and perform high-precision measurement with a small amount of specimen.

[0229] (5) A measuring system, characterized by comprising:

[0230] A measuring part (for example, 300), which includes electrodes (for example, 301, 302) having a specified shape and a substrate (for example, 303) on the surface of which the electrodes are formed;

[0231] A power supply part (for example, 200), which supplies a specified voltage;

[0232] A measuring unit (for example, 920), which measures the impedance by applying a specified voltage from the power supply part to the object to be measured via the measuring part; and

[0233] A derivation unit (for example, 920), which derives the complex dielectric constant of the object to be measured by inputting the measurement result of the measuring unit into a specified calculation formula defined based on an equivalent circuit (for example Figure 5 of (b)) corresponding to the structure of the measuring part and the object to be measured,

[0234] The equivalent circuit is defined to correspond to the electric field between the electrodes (for example, 501), the electric field on the substrate side of the electrodes (for example, 503), and the electric field on the object-to-be-measured side of the electrodes (for example, 502) in the measuring part,

[0235] The specified calculation formula is specified to include parameters representing the measurement results of the measurement unit for a standard sample (e.g., 603) and the measurement results for a background sample (e.g., 602).

[0236] According to this structure, the state of a trace amount of sample can be measured with high precision. In particular, the same measurement accuracy as that of parallel plate electrodes can be achieved with a smaller amount.

[0237] (6) A program

[0238] causes a computer (e.g., 920) to execute the following processes:

[0239] A measurement process (e.g., S1001, S1002), in which a specified voltage is applied to a measurement object (e.g., 400) via a measurement unit (e.g., 300) to measure impedance, the measurement unit including electrodes (e.g., 301, 302) having a specified shape and a substrate (e.g., 303) on which the electrodes are formed on the surface; and

[0240] A derivation process (e.g., S1003, S1004, S1005), in which the measurement result of the measurement process is input into a calculation formula specified based on an equivalent circuit (e.g., Figure 5 of (b)) corresponding to the structure of the measurement unit and the measurement object, thereby deriving the complex dielectric constant of the measurement object.

[0241] The equivalent circuit is specified to correspond to the electric field between the electrodes (e.g., 501) in the measurement unit, the electric field on the substrate side of the electrodes (e.g., 503), and the electric field on the measurement object side of the electrodes (e.g., 502).

[0242] The specified calculation formula is specified to include parameters based on the measurement results of the measurement unit for a standard sample (e.g., 603) and the measurement results for a background sample (e.g., 602).

[0243] According to this structure, the state of a trace amount of sample can be measured with high precision. In particular, the same measurement accuracy as that of parallel plate electrodes can be achieved with a smaller amount.

[0244] As described above, various embodiments have been described with reference to the drawings, but the present invention is of course not limited to this example. It is obvious that various modification examples or correction examples can be conceived by those skilled in the art within the scope described in the claims, and these modification examples or correction examples also of course belong to the technical scope of the present invention. In addition, within the scope not departing from the gist of the invention, the constituent elements in the above-described embodiments can be arbitrarily combined.

[0245] The above describes various embodiments, but the present invention is of course not limited to this example. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and these modification examples or correction examples of course also belong to the technical scope of the present invention. In addition, within the scope not departing from the gist of the invention, the constituent elements in the above embodiments can be arbitrarily combined.

[0246] In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2022-178451) filed on November 7, 2022, the content of which is incorporated herein by reference.

[0247] Explanation of Reference Numerals

[0248] 200 AC power supply

[0249] 300 Measuring unit

[0250] 301, 302 Comb electrodes

[0251] 303 Substrate

[0252] 900 Seal

[0253] 901 Rolling bearing

[0254] 902 Lubricant

[0255] 920 Measuring device

Claims

1. A measurement method, characterized in that, comprising: a measurement step of measuring impedance by applying a prescribed voltage to a measurement object via a measurement unit, the measurement unit including an electrode having a prescribed shape and a substrate on which the electrode is formed on a surface; and a derivation step of inputting the measurement result of the measurement step into a prescribed calculation formula defined based on an equivalent circuit corresponding to the structure of the measurement unit and the measurement object, thereby deriving a complex dielectric constant of the measurement object, wherein the equivalent circuit is defined to correspond to an electric field between the electrodes in the measurement unit, an electric field on the substrate side of the electrode, and an electric field on the measurement object side of the electrode, and the prescribed calculation formula is defined to include parameters based on measurement results of a standard specimen and a background specimen by the measurement unit.

2. The measurement method according to claim 1, characterized in that, The prescribed calculation formula is defined by the following: ε’: The real part component of the complex permittivity ε * ​ ε”:Imaginary part component of the complex permittivity ε * ​ Y’ STD : Real part of the complex admittance of the standard specimen Y" STD : Imaginary part of the complex admittance of the standard specimen Y″ BK : Imaginary part of the complex admittance of the background Y’ SPL : Real part of the complex admittance of the specimen Y” SPL : Imaginary part of the complex admittance of the specimen ω: angular frequency of the voltage σ tol : Conductivity of the standard specimen ε air : Dielectric constant of the background specimen ε tol : Dielectric constant of the standard specimen.

3. The measurement method according to claim 1, characterized in that, The prescribed shape is a comb shape, on the surface of the substrate, two comb-shaped electrodes are opposed to each other, and the comb teeth are arranged in a meshing manner with each other.

4. The measurement method according to claim 1, characterized in that, The measurement unit is provided in a rolling bearing, and the measurement object is a lubricant inside the rolling bearing.

5. A measurement device, characterized in that, comprising: a measurement unit including an electrode having a prescribed shape and a substrate on which the electrode is formed on a surface; a power supply unit that supplies a prescribed voltage; a measurement unit that applies a prescribed voltage from the power supply unit to a measurement object via the measurement unit, thereby measuring impedance; and a derivation unit that inputs the measurement result of the measurement unit into a prescribed calculation formula defined based on an equivalent circuit corresponding to the structure of the measurement unit and the measurement object, thereby deriving a complex dielectric constant of the measurement object, wherein the equivalent circuit is defined to correspond to an electric field between the electrodes in the measurement unit, an electric field on the substrate side of the electrode, and an electric field on the measurement object side of the electrode, and the prescribed calculation formula is defined to include parameters based on measurement results of a standard specimen and a background specimen by the measurement unit.

6. A program, characterized in that, causing a computer to execute the following steps: a measurement step of measuring impedance by applying a prescribed voltage to a measurement object via a measurement unit, the measurement unit including an electrode having a prescribed shape and a substrate on which the electrode is formed on a surface; and a derivation step of inputting the measurement result of the measurement step into a prescribed calculation formula defined based on an equivalent circuit corresponding to the structure of the measurement unit and the measurement object, thereby deriving a complex dielectric constant of the measurement object, wherein the equivalent circuit is defined to correspond to an electric field between the electrodes in the measurement unit, an electric field on the substrate side of the electrode, and an electric field on the measurement object side of the electrode, and the prescribed calculation formula is defined to include parameters based on measurement results of a standard specimen and a background specimen by the measurement unit.

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