Electrical signal measurement electrode device and electrical signal measurement system

Abstract

Provided is a device for inspecting an object with high efficiency, low cost, and high accuracy. An electrical signal measurement electrode device (electrode device 10) is connected to an electrical signal measurement unit (overall current measurement unit 22) that measures current flowing through an object T by applying an electrical signal to the object T. The electrical signal measurement electrode device comprises: a plurality of probe pins (unit probe pins 111) that can extend and contract along the axial direction; and a conductive sheet 12 that is attached to the tips of the plurality of probe pins and forms a contact surface with respect to the object T. The shape of the contact surface changes in a manner following the surface shape of the object T.

Description

Electrode device for measuring electrical signals and electrical signal measuring system

[0001] The present disclosure relates to an electrode device for measuring an electrical signal and an electrical signal measurement system.

[0002] Reinforced concrete, often used in infrastructure such as bridges and roads, as well as large-scale buildings, possesses high toughness when first manufactured or laid. However, changes in concrete properties over time, moisture penetration, and other factors cause corrosion of the internal reinforcing bars, significantly degrading its strength. In recent years, against the backdrop of environmental and energy issues, composite fiber-reinforced plastics such as carbon fiber reinforced plastics (CFRP) have increasingly been used as structural materials for the bodies of mobile objects such as aircraft and automobiles, as well as for relatively large facilities and buildings. While these composite materials offer superior characteristics of light weight and high strength compared to metals, the presence of minute voids or internal delamination during manufacturing can lead to severe damage and fracture due to aging. Therefore, nondestructive testing is being implemented to efficiently evaluate and ensure the safety and reliability of these infrastructures, large-scale buildings, mobile objects, and other such structures. Recently, due to increased consumer awareness of product safety and the resulting tightening of regulations, there has been a growing social trend toward high safety standards for consumer goods, including food products. This necessitates a need for nondestructive testing methods that can easily evaluate their quality.

[0003] Electromagnetic methods have been proposed and put into practical use as efficient, quantitative non-destructive testing methods for large or wide-area objects. Representative electromagnetic methods include impedance testing and eddy current testing. These methods involve placing electrodes on the surface of an object, applying an electric field or current to the electrodes, and measuring the electrical or magnetic properties of the object to determine its internal structure and / or properties (see, for example, Patent Documents 1 to 3).

[0004] JP 62-3654 A JP 2007-027022 A JP 2022-72806 A

[0005] In electromagnetic methods, it is necessary to ensure contact of the electrodes with the object in order to perform highly accurate testing. For this reason, conventional electromagnetic methods for non-destructive testing have involved forming a film of electrodes on the object or attaching the electrodes to the object with tape, but this has problems such as prolonged testing time, reduced efficiency, and high costs.

[0006] An object of the present disclosure is to provide an electrode device for measuring electrical signals and an electrical signal measuring system that are capable of performing testing with high efficiency, low cost, and high accuracy.

[0007] In order to solve the above problem, an electrode device for measuring an electric signal is connected to an electric signal measuring unit that measures the current flowing through an object by applying an electric signal to the object, and comprises a plurality of probe pins that are extendable and contractible along the axial direction, and a conductive sheet that is attached to the tips of the plurality of probe pins and forms a contact surface with the object, and the shape of the contact surface changes to follow the surface shape of the object.

[0008] In the electrode device for measuring an electric signal, the probe pins have a length that is not affected by noise due to surrounding radio waves and are arranged in a matrix.

[0009] In the electrode device for measuring an electric signal, the conductive sheet is formed of a flexible material.

[0010] The electrode device for measuring an electrical signal also includes a metal plate that covers the periphery of the probe pin and is expandable and contractible along the axial direction according to the surface shape of the object, and the metal plate is grounded.

[0011] Furthermore, an electrical signal measurement system includes at least one of the above-mentioned electrode devices for measuring electrical signals and the electrical signal measurement unit, wherein the electrical signal is any one of a DC signal, an AC signal, and a transient signal, and the electrical signal measurement unit measures the current flowing through the object between a plurality of electrodes including the electrode device for measuring electrical signals.

[0012] The electrical signal measurement system also includes a correction unit that corrects the measurement results by removing signals due to the contact resistance of the electrical signal measurement electrode device from the measurement results of the electrical signal measurement unit through equivalent circuit analysis.

[0013] The electrical signal measurement system also includes a pressing pressure measurement unit that measures the pressing pressure of the probe pin for each probe pin or for each row of probe pins, and / or a unit measurement unit that measures the current flowing through the object for each probe pin or for each row of probe pins, and the electrical signal measurement unit aggregates the measurement results of the unit measurement units.

[0014] The electrical signal measurement system further comprises wiring connected to the indentation pressure measurement unit and / or the unit measurement unit for each of the probe pins or for each row of the probe pins, and the wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit.

[0015] The electrical signal measurement system also includes a correction unit that calculates the distribution of the indentation pressure on the contact surface based on the measurement results of the indentation pressure measurement unit and / or calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit, and corrects the measurement results of the electrical signal measurement unit based on the distribution of the indentation pressure and / or the area of ​​the contact surface.

[0016] The electrical signal measurement system also includes a pressing depth measurement unit that measures the pressing depth of the probe pin for each probe pin or for each row of the probe pins, and / or a unit measurement unit that measures the current flowing through the object for each probe pin or for each row of the probe pins, and the electrical signal measurement unit aggregates the measurement results of the unit measurement units.

[0017] The electrical signal measurement system further comprises wiring connected to the indentation depth measurement unit and / or the unit measurement unit for each of the probe pins or for each row of the probe pins, and the wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit.

[0018] The electrical signal measurement system also includes a correction unit that calculates the distribution of the indentation depth on the contact surface based on the measurement results of the indentation depth measurement unit and / or calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit, and corrects the measurement results of the electrical signal measurement unit based on the distribution of the indentation depth and / or the area of ​​the contact surface.

[0019] According to the present disclosure, highly efficient, low-cost, and highly accurate inspection is possible.

[0020] 1 is a diagram illustrating an outline of the overall configuration of an electrical signal measurement system according to a first embodiment of the present disclosure. FIG. 2 is a diagram illustrating a measurement region of the electrical signal measurement system according to the first embodiment of the present disclosure. FIG. 3 is a block diagram illustrating a functional configuration of the electrical signal measurement system according to the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating a configuration of a unit probe pin. FIG. 5 is a diagram illustrating a configuration of a unit probe pin. FIG. 6 is a diagram illustrating a tip shape of a unit probe pin. FIG. 7 is a diagram illustrating a tip shape of a unit probe pin. FIG. 8 is a diagram illustrating a metal plate covering the periphery of a unit probe pin. FIG. 9 is a diagram illustrating a frequency characteristic of a phase difference measured without a conductive sheet. FIG. 10 is a diagram illustrating a frequency characteristic of a phase difference measured with a conductive sheet. FIG. 11 is a diagram illustrating a frequency characteristic of an impedance measured without a conductive sheet and a frequency characteristic of an impedance measured with a conductive sheet. FIG. 12 is a diagram illustrating a state in which a metal plate serving as an electrode is placed on an object via a thick-film conductive sheet. FIG. 13 is a diagram illustrating a state in which a probe pin is placed on an object via a thin-film conductive sheet. FIG. 14 is a diagram illustrating a frequency characteristic of an impedance measured when the contact resistance between the object and the conductive sheet is changed. FIG. 15 is a diagram illustrating a frequency characteristic of a phase difference measured when the contact resistance between the object and the conductive sheet is changed. FIG. 16 is a flowchart illustrating a flow of an electrical signal measurement process. FIG. 17 is a diagram illustrating an equivalent circuit of an electrode device and an object. 1 is a diagram showing the impedance of an electrical signal before correction and the impedance of an electrical signal after correction processing by equivalent circuit analysis; FIG. 2 is a diagram showing the phase difference of an electrical signal before correction and the phase difference of an electrical signal after correction processing by equivalent circuit analysis; FIG. 3 is a diagram explaining an outline of the overall configuration of an electrical signal measurement system according to a second embodiment of the present disclosure; FIG. 4 is a diagram showing a measurement region of the electrical signal measurement system according to the second embodiment of the present disclosure;

[0021] However, the scope of the present invention is not limited to the illustrated examples and includes forms and configurations equivalent thereto.

[0022] First Embodiment FIG. 1 is a schematic diagram of an electrical signal measurement system 100 and an object T. FIG. 2 is a diagram showing a measurement area Ta of the electrical signal measurement system 100. FIG. 3 is a block diagram showing a functional configuration of the electrical signal measurement system 100. As shown in FIG. 1 , the electrical signal measurement system 100 applies an electrical signal to the object T in a state in which a first electrode device 10A and a second electrode device 10B are pressed from above (the positive Z-axis direction side) against the same surface of the object T (e.g., the surface on the positive Z-axis direction side) and brought into contact with each other. In this state, as shown in FIG. 2 , the electrical signal measurement system 100 measures the current value of the electrical signal that passes through the measurement area Ta of the object T between the first electrode device 10A and the second electrode device 10B. The electrical signal measurement system 100 performs non-destructive testing of the object T by estimating the probability of the presence of defects, foreign matter, corrosion, etc. in the object T from the measurement results of the current value. Hereinafter, when there is no need to distinguish between the first electrode device 10A and the second electrode device 10B, they will be collectively referred to as the electrode device 10. The electrode device 10 functions as an electrode device for measuring electrical signals. The electrical signal measurement system 100 includes the electrode device 10, a measurement device 20, and a control device 30.

[0023] The object T is, for example, a relatively large structural material such as reinforced concrete (concrete structure), transportation aircraft parts, etc., but is not limited to these. The object T may also be a semiconductor, an insulator, a conductor, a material whose electrical properties change depending on the environment, a metal structural material, a composite material made of filler and resin (CFRP, etc.), a composite material made of metal or resin, etc. The electrical signal measurement system 100 measures the current of the electrical signal that passes through the inside of the object T, thereby performing a structural inspection of the object T, defect detection (inspection for foreign objects, cracks, peeling, voids, etc.), etc.

[0024] The electrode device 10 includes a first electrode device 10A and a second electrode device 10B. The first electrode device 10A and the second electrode device 10B are placed at a predetermined distance from each other so as to be in contact with the surface of the object T.

[0025] The electrode device 10 includes a probe pin section 11 having a plurality of unit probe pins 111 for detecting the current of an electrical signal, a conductive sheet 12, a substrate 13, etc. The unit probe pin 111 refers to one electrode terminal.

[0026] The plurality of unit probe pins 111 are arranged in a matrix on the substrate 13. The plurality of unit probe pins 111 are set to a length that is not affected by noise from surrounding radio waves, and are arranged on the substrate 13 at intervals that do not cause radio wave interference between them. Specifically, the length of the unit probe pins 111 is shorter than 1 / 20 of the wavelength of the maximum measurement frequency. For example, when the maximum measurement frequency is 1 GHz, the length of the unit probe pins 111 is set to 15 mm or less. When the maximum measurement frequency is 10 MHz, the length of the unit probe pins 111 is set to 1500 mm or less.

[0027] Each unit probe pin 111 is extendable and retractable along its axial direction in accordance with the surface shape of the target object T. As shown in Fig. 4, each unit probe pin 111 includes a spring 111a, a damper, a bush (not shown), etc., provided on the tip side where the conductive sheet 12 is attached, and a terminal 111b moves along the axial direction. Alternatively, as shown in Fig. 5, each unit probe pin 111 includes a spring 111a, a damper, a bush, etc., provided on the side opposite to the tip side, and a terminal 111c moves along the axial direction.

[0028] The spring 111a affects the measurement results of the current of the electric signal in the high frequency range in the electric signal measurement system 100. Therefore, when measuring the current of a high frequency electric signal, it is preferable to use a unit probe pin 111 that is expandable and contractible along the axial direction without using the spring 111a. In this case, the unit probe pin 111 is provided with, for example, a damper having a conductive liquid therein, thereby realizing a configuration that is expandable and contractible along the axial direction.

[0029] The conductive sheet 12 is attached to the tips of the multiple unit probe pins 111 and comes into contact with the surface of the object T. In other words, the conductive sheet 12 forms a contact surface with the object T. The conductive sheet 12 is made of a flexible material and is a thin film (e.g., 1 mm), so it deforms according to the surface shape of the object T. This improves the contact between the electrode device 10 and the surface of the object T. The conductive sheet 12 may be a conductive film, gel, or the like. An appropriate material may be used for the conductive sheet 12 depending on the object T.

[0030] With the above configuration, the shape of the contact surface of the electrode device 10 with the surface of the object T changes to follow the surface shape of the object T. As a result, even if the surface of the object T has an uneven shape, the electrode device 10 can be brought into contact with the object T and the current value of the electrical signal can be measured appropriately.

[0031] Next, the adhesion between the unit probe pins 111 and the conductive sheet 12 will be described below. The adhesive force between the unit probe pins 111 and the conductive sheet 12 is greater than the adhesive force between the conductive sheet 12 and the object T. Specifically, when an adhesive sheet is used as the conductive sheet 12, the adhesive force between the conductive sheet 12 and the object T can be reduced by performing a process of dusting metal powder on the surface of the conductive sheet 12 that comes into contact with the object T. This makes it possible to prevent the conductive sheet 12 from adhering to the object T and contaminating the surface of the object T when the electrode device 10 is peeled off from the object T.

[0032] 6A, when the tip of the unit probe pin 111 has a rounded tapered shape, it has lower adhesion to the conductive sheet 12 than when it has a flat shape (see FIG. 6B) or a jagged shape (see FIG. 6C). Therefore, when the adhesive sheet that is the conductive sheet 12 does not have sufficient adhesiveness, it is preferable that the tip of the unit probe pin 111 has a flat shape or a jagged shape. When the tip of the unit probe pin 111 has a jagged shape, the tip of the unit probe pin 111 may be embedded in the conductive sheet 12.

[0033] When the object T has a relatively low impedance, the electrical signal measurement system 100 may include four electrode devices 10. In this case, the four electrode devices 10 are installed in a row at a predetermined interval on the same surface of the object T (e.g., the surface on the positive Z-axis direction side). The measurement device 20 is connected to the four electrode devices 10. The measurement device 20 outputs an electrical signal to one of the electrode devices 10 installed on the outside, and measures the current value of the electrical signal that has passed through the inside of the object T via the other electrode device 10 installed on the outside. The measurement device 20 uses a pair of electrode devices 10 installed on the inside to measure the potential difference of the electrical signal that has passed through the inside of the object T between the pair of electrode devices 10.

[0034] In the electrode device 10, the substrate 13 may be covered with a metal plate or metal foil, thereby reducing low-frequency noise such as power supply noise on the substrate 13.

[0035] 7, the electrode device 10 may include a metal plate 14 that covers the periphery of each of the plurality of unit probe pins 111. This reduces ambient radio wave noise for the unit probe pins 111. The metal plate 14 has a telescopic structure and is extendable along the axial direction of the unit probe pins 111, together with the unit probe pins 111, in accordance with the surface shape of the target T. The metal plate 14 is grounded, and therefore functions as a guard electrode that prevents electrical signals applied to the target T from leaking outside the electrode device 10.

[0036] The measurement device 20 is connected to the first electrode device 10A and the second electrode device 10B. The measurement device 20 outputs an electrical signal to the first electrode device 10A and measures the current value of the electrical signal that passes through the inside of the subject T via the second electrode device 10B. The measurement device 20 includes a signal generation unit 21, a total current measurement unit 22 as an electrical signal measurement unit, a unit current measurement unit 23 as a unit measurement unit, and an indentation pressure measurement unit 24.

[0037] The signal generating unit 21 generates an electric signal and outputs it to the first electrode device 10A under the control of the control device 30. As a result, the signal generating unit 21 applies the electric signal to the subject T via the electrode device 10. The electric signal applied to the subject T is any one of a DC signal, an AC signal, and a transient signal such as a pulse signal. When a DC signal is used as the electric signal to be applied to the subject T, the signal generating unit 21 controls the DC voltage, DC current, etc. of the DC signal to be applied to the electrode device 10 under the control of the control device 30. When an AC signal is used as the electric signal to be applied to the subject T, the signal generating unit 21 controls the frequency, frequency range, AC signal amplitude (AC voltage amplitude, AC current amplitude), etc. of the AC signal to be applied to the electrode device 10 under the control of the control device 30.

[0038] The total current measuring unit 22 and the unit current measuring unit 23 measure the current value of the electric signal flowing inside the object T when the electric signal output from the signal generating unit 21 is applied. The measuring device 20 may include a measuring unit that measures an electric characteristic parameter instead of the total current measuring unit 22 and the unit current measuring unit 23. The electric characteristic parameter is, for example, the phase difference, voltage value, electric resistance value, impedance, admittance of the AC electric signal, or the dielectric constant, conductivity, etc. derived therefrom.

[0039] Wiring that connects to each unit probe pin 111 is connected to the unit current measurement unit 23. The unit current measurement unit 23 measures the current value of the electrical signal flowing inside the object T for each unit probe pin 111. Alternatively, wiring that connects to each pin row formed by a plurality of unit probe pins 111 lined up in a row is connected to the unit current measurement unit 23. In this case, the unit current measurement unit 23 measures the current value of the electrical signal flowing inside the object T for each pin row. The wiring that connects the unit probe pins 111 and the unit current measurement units 23 is aggregated and connected to the overall current measurement unit 22. As a result, the overall current measurement unit 22 aggregates the measurement results of the unit current measurement units 23. In other words, the overall current measurement unit 22 measures the current value of the electrical signal flowing inside the object T by the entire probe pin unit 11.

[0040] Wiring is connected to each unit probe pin 111 to the indentation pressure measuring unit 24. The indentation pressure measuring unit 24 measures the indentation pressure of each unit probe pin 111 when it contracts in the axial direction when the electrode device 10 is placed on the surface of the object T by pressing it down from above. Alternatively, the indentation pressure measuring unit 24 measures the indentation pressure of each unit probe pin 111 when it contracts in the axial direction for each pin row made up of a plurality of unit probe pins 111 when the electrode device 10 is placed on the surface of the object T by pressing it down from above.

[0041] The measuring device 20 may include an indentation depth measuring unit instead of the indentation pressure measuring unit 24. The indentation depth measuring unit measures the indentation depth of each unit probe pin 111 when the electrode device 10 is placed on the surface of the object T by pressing it down from above. Alternatively, the indentation depth measuring unit measures the indentation depth of each unit probe pin 111 when the unit probe pins 111 are placed on the surface of the object T by pressing it down from above.

[0042] When measuring the current flowing through a material with an uneven surface, such as concrete or a porous material, as the object T, the measurement results of the overall current measurement unit 22 may vary due to local changes in current caused by the material, surface shape, etc. of the object T. The measurement device 20 can acquire information (surface information) about the portion of the surface of the object T with which the electrode device 10 is in contact, using the unit current measurement unit 23 and the indentation pressure measurement unit 24. Therefore, by having the measurement device 20 acquire the surface information of the object T, it is possible to determine whether the measurement results of the overall current measurement unit 22 reflect the influence of the surface condition of the object T or the influence of the internal condition of the object T.

[0043] The control device 30 is connected to the measuring device 20, controls the measuring device 20, and acquires measurement results of the current value of the electrical signal from the measuring device 20. The control device 30 includes a control unit 31, an operation unit 32, a display unit 33, a communication unit 34, and a storage unit 35.

[0044] The control unit 31 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), etc., and executes a series of operations in the control device 30. Specifically, the CPU reads out various processing programs stored in the storage unit 35, loads them into the RAM, and performs various processes in cooperation with the programs.

[0045] The operation unit 32 includes a keyboard having cursor keys, character input keys, various function keys, etc., and a pointing device such as a mouse. The operation unit 32 outputs operation signals input by key operations on the keyboard, mouse operations, etc., to the control unit 31. The operation unit 32 may include a touch panel or the like, and output operation signals to the control unit 31 according to the position of an operation by the operator's finger, etc.

[0046] The display unit 33 includes a monitor such as an LCD (Liquid Crystal Display), and displays various screens according to instructions of a display signal input from the control unit 31 .

[0047] The communication unit 34 includes a network interface, etc. The communication unit 34 transmits and receives data to and from external devices connected via a communication network N such as a local area network (LAN), a wide area network (WAN), or the Internet.

[0048] The storage unit 35 includes a hard disk drive (HDD), a nonvolatile semiconductor memory, etc., and stores various data.

[0049] Next, the effect of the electrode device 10 including the conductive sheet 12 will be described. FIG. 8 is a graph showing the frequency characteristics of the phase difference between an input AC electrical signal applied via an electrode device not including the conductive sheet 12 and an output AC electrical signal measured via the electrode device not including the conductive sheet 12. FIG. 9 is a graph showing the frequency characteristics of the phase difference between an input AC electrical signal applied via the electrode device 10 including the conductive sheet 12 and an output AC electrical signal measured via the electrode device 10 including the conductive sheet 12. FIGS. 8 and 9 show the results of multiple measurements of the frequency characteristics of the phase difference. When an electrode device not including the conductive sheet 12 is placed on the surface of an object and the probe pins 11 are brought into direct contact with the object, the surface shape of the object may result in insufficient contact of the probe pins 11 with the object. Therefore, each time the probe pins 11 contact the object during multiple measurements, the contact resistance between the object and the probe pins 11 may change. This causes variations in the frequency characteristics of the phase difference among the multiple measurements, as shown in FIG. 8 . On the other hand, when the electrode device 10 including the conductive sheet 12 is placed on the object, the conductive sheet 12 improves the contact of the electrode device 10 with the object. Therefore, the contact resistance between the object and the electrode device 10 is less likely to change over multiple measurements. As a result, as shown in Figure 9, the variation in the frequency characteristics of the phase difference between multiple measurements is smaller than that shown in Figure 8. In other words, the stability of the measurement of the electrical signal for the object can be improved.

[0050] 10 is a diagram showing the impedance (dashed line) of an electrical signal measured via an electrode device not including a conductive sheet 12, and the impedance (solid line) of an electrical signal measured via an electrode device 10 including a conductive sheet 12. In the example shown in FIG. 10, the diameter of the unit probe pins 111 is 1 mm, the probe pin section 11 includes 33 unit probe pins 111, and the area of ​​the conductive sheet 12 is 300 mm ２ In this case, the contact area between the probe pin portion 11 and the object in the electrode device without the conductive sheet 12 is approximately 26 mm ２On the other hand, the contact area between the electrode device 10 including the conductive sheet 12 and the object is 300 mm 2 , which is the area of ​​the conductive sheet 12. ２ In other words, when the probe pin section 11 includes the same number of unit probe pins 111, the contact area between the electrode device 10 and the object can be increased by including the conductive sheet 12 in the electrode device 10. Therefore, even with a relatively small number of unit probe pins 111, a sufficient contact area between the electrode device 10 and the object can be ensured, and therefore the number of unit probe pins 111 can be reduced in the electrode device 10 including the conductive sheet 12 compared to an electrode device not including the conductive sheet 12.

[0051] 10 , across the entire measured frequency range, the impedance of the electrical signal measured through the electrode device 10 including the conductive sheet 12 is smaller than the impedance of the electrical signal measured through the electrode device without the conductive sheet 12. In other words, when the probe pin unit 11 includes the same number of unit probe pins 111, the impedance and electrical resistance value of the measured electrical signal can be reduced by measuring through the electrode device 10 including the conductive sheet 12 compared to an electrode device without the conductive sheet 12. Therefore, even if the measurement device 20 is an apparatus that cannot measure relatively large impedances, the impedance of the electrical signal can be measured through the electrode device 10 including the conductive sheet 12. Even if the measurement device 20 is an apparatus that cannot measure relatively large electrical resistance values, the electrical resistance value of the electrical signal can be measured through the electrode device 10 including the conductive sheet 12.

[0052] By including the conductive sheet 12 in the electrode device 10, it is possible to prevent voltage concentration on some of the unit probe pins 111 when an electrical signal is applied to an object via the electrode device 10. If an electrode device without the conductive sheet 12 is placed on the surface of an object and the probe pin section 11 is brought into direct contact with the object, the contact of the probe pin section 11 with the object may be insufficient depending on the surface shape of the object. If the contact of the probe pin section 11 with the object is poor, voltage may be concentrated and applied to some of the unit probe pins 111 when an electrical signal is applied to the object via the electrode device. On the other hand, if the electrode device 10 with the conductive sheet 12 is placed on the surface of an object and the conductive sheet 12 is brought into contact with the object, voltage can be applied uniformly when an electrical signal is applied.

[0053] Next, we will explain the effect of reducing the number of unit probe pins 111 in the electrode device 10 compared to the number in an electrode device not provided with the conductive sheet 12. For example, in an electrode device not provided with the conductive sheet 12, if the contact area between the probe pin portion 11 and the target object is reduced to 50 mm ２ In this case, if unit probe pins 111 each having a diameter of 2 mm and a contact area with the object of 2 mm are used, 807 unit probe pins 111 are required. On the other hand, if the contact area between the electrode device 10 including the conductive sheet 12 and the object is 50 mm ２ In this case, if unit probe pins 111 each having a diameter of 2 mm are attached to the substrate 13 at intervals of 5 mm, 121 unit probe pins 111 are required. ２ In this case, the number of unit probe pins 111 in the electrode device 10 having the conductive sheet 12 can be reduced to one-eighth compared to an electrode device not having the conductive sheet 12.

[0054] When the number of unit probe pins 111 in the electrode device 10 is reduced, the size of the substrate 13 on which the unit probe pins 111 are attached can be reduced. This allows the electrode device 10 to be miniaturized. When the number of unit probe pins 111 in the electrode device 10 is reduced, the pressing pressure of the entire unit probe pins 111 when the electrode device 10 is placed by pressing it down on the surface of an object can be reduced. For example, if the force required to press the unit probe pins 111 1 cm is 50 gf and the probe pin section 11 of the electrode device not including the conductive sheet 12 has 807 unit probe pins 111 as described above, the force pressing the electrode device against the object is approximately 43 kgf. On the other hand, if the force required to press the unit probe pins 111 1 cm is approximately 50 gf and the probe pin section 11 of the electrode device 10 including the conductive sheet 12 has 121 unit probe pins 111 as described above, the force pressing the electrode device 10 against the object is 6 kgf. Reducing the number of unit probe pins 111 in electrode device 10 can reduce the cost of the unit probe pins 111. For example, if each unit probe pin 111 costs 200 yen and the probe pin section 11 of an electrode device not provided with conductive sheet 12 has 807 unit probe pins 111 as described above, the total cost of the unit probe pins 111 is approximately 160,000 yen. On the other hand, if each unit probe pin 111 costs 200 yen and the probe pin section 11 of an electrode device 10 provided with conductive sheet 12 has 121 unit probe pins 111 as described above, the total cost of the unit probe pins 111 is approximately 24,000 yen.

[0055] Next, the effect of using unit probe pins 111 that are extendable in the axial direction and a thin conductive sheet 12 in combination in the electrode device 10 will be described. FIG. 11 shows an electrode device including a metal plate D as an electrode and a 30 mm-thick conductive sheet E, placed on an object T having an uneven surface. In the example shown in FIG. 11 , if the conductive sheet E is 50 mm square and has a resistivity of 1000 Ω·cm, the contact resistance between the object T and the conductive sheet E is 120 Ω. FIG. 12 shows an electrode device 10 including multiple unit probe pins 111 that are extendable in the axial direction and a thin conductive sheet 12 (e.g., 1 mm thick), placed on an object T having an uneven surface. In the example shown in FIG. 12 , if the conductive sheet 12 is 50 mm square and has a resistivity of 1000 Ω·cm, the contact resistance between the object T and the conductive sheet 12 is 4 Ω. As described above, the contact resistance between the object and the conductive sheet increases as the conductive sheet becomes thicker. Therefore, as shown in FIG. 12, by using a plurality of unit probe pins 111 that are axially extendable and retractable in combination with a thin conductive sheet 12, it is possible to reduce the contact resistance between the object and the conductive sheet while ensuring the mobility of the electrode device 10 relative to the surface of the object.

[0056] FIG. 13 shows the frequency characteristics of the impedance of the measured electrical signal when the contact resistance between the object and the conductive sheet is changed. FIG. 14 shows the frequency characteristics of the phase difference between the applied input AC electrical signal and the measured output AC electrical signal when the contact resistance between the object and the conductive sheet is changed. In the example shown in FIGS. 13 and 14 , if the contact resistance between the object and the conductive sheet, represented by a parallel circuit with resistance R = 1 MΩ and capacitance C = 10 μF, is 1 Ω, electrical signals below 10 kHz can be considered to be signals originating from the object. As shown in FIG. 13 , in the high-frequency range (e.g., 100 Hz or higher), the impedance of the measured electrical signal is significantly affected by the contact resistance between the object and the conductive sheet. As shown in FIG. 14 , in the high-frequency range (e.g., 100 Hz or higher), the phase difference between the applied input AC electrical signal and the measured output AC electrical signal is significantly affected by the contact resistance between the object and the conductive sheet. Therefore, by using a plurality of unit probe pins 111 that are extendable and retractable in the axial direction in combination with the thin conductive sheet 12, the contact resistance between the object and the conductive sheet can be reduced, thereby reducing the effect of the contact resistance on the impedance and phase difference of the measured electrical signal.

[0057] Next, a description will be given of the operation of the electrical signal measurement system 100. Fig. 15 is a flowchart showing the electrical signal measurement process executed by the electrical signal measurement system 100.

[0058] (Electrical Signal Measurement Processing) The first electrode device 10A and the second electrode device 10B are placed on the surface of the target object T with a predetermined gap therebetween, pressing them down from above. In this state, the indentation pressure measurement unit 24 of the measurement device 20 measures the indentation pressure of each unit probe pin 111 when it contracts in the axial direction. Alternatively, the indentation pressure measurement unit 24 measures the indentation pressure of each unit probe pin 111 when it contracts in the axial direction for each pin row made up of a plurality of unit probe pins 111. The indentation pressure measurement unit 24 outputs the indentation pressure measurement results to the control device 30 (step S1). Instead of step S1, the indentation depth measurement unit may measure the indentation depth of each unit probe pin 111 when it contracts in the axial direction. Alternatively, the indentation depth measurement unit may measure the indentation depth of each unit probe pin 111 when it contracts in the axial direction for each pin row made up of a plurality of unit probe pins 111. In this case, the indentation depth measurement unit outputs the indentation depth measurement results to the control device 30.

[0059] Next, the signal generating unit 21 of the measuring device 20 inputs the generated electrical signal to the first electrode device 10A under the control of the control device 30. As a result, the signal generating unit 21 applies the electrical signal to the target T via the first electrode device 10A (step S2).

[0060] Next, the unit current measurement unit 23 of the measurement device 20 uses the second electrode device 10B to measure the current value of the electrical signal that has passed through the measurement area Ta of the object T for each unit probe pin 111. Alternatively, the unit current measurement unit 23 measures the current value of the electrical signal that has passed through the measurement area Ta of the object T for each pin row composed of a plurality of unit probe pins 111. The unit current measurement unit 23 outputs the measurement results of the current value measured for each unit probe pin 111 or for each pin row to the control device 30 (step S3). Next, the overall current measurement unit 22 measures the current value of the electrical signal detected by the entire probe pin unit 11 provided in the second electrode device 10B. The overall current measurement unit 22 outputs the measurement results of the current value measured by the entire probe pin unit 11 to the control device 30 (step S4).

[0061] The control unit 31 of the control device 30 determines whether or not an abnormality such as variation has occurred in the measurement results of the pressing pressure for each unit probe pin 111 or each pin row acquired in step S1. Alternatively, the control unit 31 may determine whether or not an abnormality such as variation has occurred in the measurement results of the pressing depth for each unit probe pin 111 or each pin row. Furthermore, the control unit 31 determines whether or not an abnormality such as variation has occurred in the measurement results of the current value for each unit probe pin 111 or each pin row acquired in step S3 (step S5). If no abnormality has occurred in step S5 (step S5; NO), the control unit 31 proceeds to step S7 in the electrical signal measurement process.

[0062] On the other hand, if any abnormality has occurred in step S5 (step S5; YES), the control unit 31 corrects the measurement result of the current value for the entire probe pin unit 11 obtained in step S4 (step S6). The control unit 31 functions as a correction unit. Specifically, the control unit 31 calculates an average value of the measurement results of the indentation pressure for each unit probe pin 111 or each pin row obtained in step S1, and corrects the measurement result of the current value using the calculated average value. For example, the control unit 31 corrects the measurement result of the current value by taking the calculated average value as the effective indentation pressure and multiplying the measurement result of the current value by the ratio of the effective value to the input value of the indentation pressure for each unit probe pin 111 or each pin row. Alternatively, the control unit 31 calculates an average value of the measurement results of the indentation depth for each unit probe pin 111 or each pin row, and corrects the measurement result of the current value using the calculated average value. For example, the control unit 31 sets the calculated average value as the effective indentation depth, and performs correction by multiplying the measurement result of the current value by the ratio of the effective value to the input value of the indentation depth for each unit probe pin 111 or for each pin row. The control unit 31 calculates the distribution of indentation pressure at the contact surface between the electrode device 10 and the object from the measurement result of the indentation pressure for each unit probe pin 111 or for each pin row acquired in step S1. The control unit 31 corrects the measurement result of the current value using the calculated distribution of indentation pressure. Alternatively, the control unit 31 calculates the distribution of indentation depth at the contact surface between the electrode device 10 and the object from the measurement result of the indentation depth for each unit probe pin 111 or for each pin row. The control unit 31 corrects the measurement result of the current value using the calculated distribution of indentation depth. The control unit 31 determines that a location where the measurement result of the current value for each unit probe pin 111 or for each pin row has variation compared to other locations is a location with poor contact. The control unit 31 corrects the area of ​​the contact surface by subtracting the poor contact area from the area of ​​the contact surface between the electrode device 10 and the object. The control unit 31 corrects the measurement result of the current value based on the corrected area of ​​the contact surface.

[0063] Next, the control unit 31 displays the measurement result of the current value by the entire probe pin unit 11 acquired in step S4 or the measurement result of the current value corrected in step S6 on the display unit 33. Furthermore, the control unit 31 stores the measurement result in the memory unit 35 (step S7) and ends the electrical signal measurement process. The control unit 31 may estimate the probability of the presence of defects, foreign matter, corrosion, etc. in the object T from the measurement result of the current value.

[0064] In the above-described electrical signal measurement process, the control unit 31 may omit step S1. In this case, in step S5, the control unit 31 determines whether or not an abnormality such as variation has occurred in the measurement results of the current value for each unit probe pin 111 or for each pin row acquired in step S3. In step S6, the control unit 31 calculates the area of ​​the contact surface between the electrode device 10 and the object based on the measurement results of the unit current measurement unit 23, and corrects the measurement results of the current value for the entire probe pin unit 11 based on the calculated area of ​​the contact surface.

[0065] In step S5 of the electrical signal measurement process, the control unit 31 may omit determining whether or not an abnormality such as variation has occurred in the measurement results of the current value for each unit probe pin 111 or each pin row obtained in step S3. In this case, in step S6, the control unit 31 calculates the distribution of indentation pressure at the contact surface between the electrode device 10 and the object based on the measurement results of the indentation pressure measurement unit 24. Next, the control unit 31 corrects the measurement results of the current value by the entire probe pin unit 11 based on the calculated distribution of indentation pressure. Alternatively, the control unit 31 calculates the distribution of indentation depth at the contact surface between the electrode device 10 and the object based on the measurement results of the indentation depth measurement unit. Next, the control unit 31 corrects the measurement results of the current value by the entire probe pin unit 11 based on the calculated distribution of indentation depth.

[0066] The control unit 31 of the control device 30 may perform correction on the measurement results obtained from the measurement device 20 to reduce the influence of contact resistance between the object and the conductive sheet 12 on the impedance and phase difference of the electrical signal. This correction is preferably performed particularly at high frequencies. Specifically, as shown in FIG. 16 , the control unit 31 corrects the impedance and phase difference of the measured electrical signal by regarding the equivalent circuit of the electrode device 10 as a resistor R2 and the equivalent circuit of the object as a resistor R1 and a capacitor C1. Alternatively, the control unit 31 may correct the impedance and phase difference of the measured electrical signal by regarding the equivalent circuit of the electrode device 10 as a parallel circuit of a resistor and a capacitor. In other words, the control unit 31 corrects the measurement results by removing the signal due to the contact resistance of the electrode device 10 from the measurement results of the total current measurement unit 22 through equivalent circuit analysis.

[0067] Figure 17 shows the measured impedance of the electrical signal before correction (dashed line) and the impedance of the electrical signal after correction processing by equivalent circuit analysis where the equivalent circuit of the electrode device 10 has a resistance R2 = 1000Ω (solid line). Figure 18 shows the phase difference of the measured electrical signal before correction (dashed line) and the phase difference of the electrical signal after correction processing by equivalent circuit analysis where the equivalent circuit of the electrode device 10 has a resistance R2 = 1000Ω (solid line). As described above, by removing the signal component caused by the contact resistance between the electrode device 10 and the target object from the electrical signal acquired via the electrode device 10 through analysis using an equivalent circuit, the true electrical signal from the target object can be obtained. In other words, the electrical signal originating from the target object can be obtained.

[0068] Second Embodiment Next, a second embodiment will be described, focusing on the differences from the first embodiment.

[0069] Fig. 19 is a schematic diagram of an electrical signal measurement system 100b according to the second embodiment and a target object T. Fig. 20 is a diagram showing a measurement region Tb of the electrical signal measurement system 100 according to the second embodiment. The electrical signal measurement system 100b includes one electrode device 10, a planar electrode 40, a measurement device 20, and a control device 30.

[0070] As shown in Fig. 19 , the electrical signal measurement system 100b applies an electrical signal to the object T in a state in which the electrode device 10 is in contact with the top surface (the surface on the positive side of the Z axis) of the object T and pressed down from above, and the flat electrode 40 is in contact with the entire bottom surface (the surface on the negative side of the Z axis) of the object T. In other words, the electrode device 10 and the flat electrode 40 are placed in positions facing each other with the object T sandwiched between them in the Z axis direction. As shown in Fig. 20 , the electrical signal measurement system 100b measures the current of the electrical signal that passes through the measurement region Tb of the object T between the electrode device 10 and the flat electrode 40. The flat electrode 40 is a solid electrode made of a copper plate, SUS (stainless steel) plate, or the like.

[0071] In the second embodiment, the measurement device 20 is connected to the electrode device 10 and the planar electrode 40. The measurement device 20 outputs an electrical signal to the electrode device 10 and measures the current value of the electrical signal that passes through the inside of the subject T via the planar electrode 40. In the second embodiment, the flow of the electrical signal measurement process is the same as in the first embodiment.

[0072] <Effects> As described above, the electrode device for measuring electrical signals (electrode device 10) of this embodiment is an electrode device for measuring electrical signals that is connected to an electrical signal measurement unit (total current measurement unit 22) that applies an electrical signal to the subject T to measure the current flowing through the subject T. The electrode device for measuring electrical signals includes a plurality of probe pins (unit probe pins 111) that are extendable and contractible along the axial direction. The electrode device for measuring electrical signals includes a conductive sheet 12 that is attached to the tips of the plurality of probe pins and forms a contact surface with the subject T. The shape of the contact surface of the electrode device for measuring electrical signals changes to follow the surface shape of the subject T. This improves the contact ability of the electrode device 10 even with subjects that have uneven or non-flat surfaces. Even when the electrode device 10 has a relatively small number of unit probe pins 111, the conductive sheet 12 can increase the contact area with the subject. This increases the signal strength when the electrode device 10 detects an electrical signal, leading to cost reduction. The conductive sheet 12 can be made of an appropriate material depending on the compatibility with the object, further improving the contact of the electrode device 10. This allows for highly efficient, low-cost, and highly accurate testing.

[0073] In the electrode device for measuring an electric signal (electrode device 10) of this embodiment, the probe pins (unit probe pins 111) have a pin length that is not affected by noise from surrounding radio waves, and are arranged in a matrix. This makes it possible to measure the current value of an electric signal that has passed through a target object with high accuracy without being affected by noise from surrounding radio waves.

[0074] In the electrode device for measuring an electrical signal (electrode device 10) of this embodiment, the conductive sheet 12 is formed of a flexible material, which improves the contact between the electrode device 10 and the surface of the object T. Therefore, the current value of the electrical signal that has passed through the object can be measured with high accuracy.

[0075] The electrode device for measuring an electric signal (electrode device 10) of this embodiment includes a metal plate 14 that covers the periphery of the probe pin (unit probe pin 111) and is expandable and contractible along the axial direction in accordance with the surface shape of the object T. The metal plate 14 is grounded. This reduces ambient radio wave noise for the unit probe pin 111. It is also possible to prevent the electric signal applied to the object T from leaking outside the electrode device 10. Therefore, it is possible to measure the current value of the electric signal that has passed through the object T with high accuracy.

[0076] The electrical signal measurement system 100 of this embodiment includes at least one electrode device for measuring electrical signals (electrode device 10). The electrical signal measurement system 100 also includes an electrical signal measurement unit (total current measurement unit 22). The electrical signal is either a DC signal, an AC signal, or a transient signal. The electrical signal measurement unit measures the current flowing through the object T between multiple electrodes including the electrode device for measuring electrical signals. By using the electrode device 10, the contact of the electrode device 10 with an object having an uneven surface can be improved. Even if the electrode device 10 has a relatively small number of unit probe pins 111, the conductive sheet 12 can increase the contact area with the object. This increases the signal strength when the electrode device 10 detects an electrical signal, leading to cost reduction. The conductive sheet 12 can be made of an appropriate material selected depending on its compatibility with the object, further improving the contact of the electrode device 10. This allows for highly efficient, low-cost, and highly accurate testing.

[0077] The electrical signal measurement system 100 of this embodiment includes a correction unit (control unit 31) that corrects the measurement results by removing signals due to the contact resistance of the electrode device for measuring electrical signals (electrode device 10) from the measurement results of the electrical signal measurement unit (total current measurement unit 22) through equivalent circuit analysis. This makes it possible to obtain a true electrical signal from the subject by removing signal components due to the contact resistance between the subject and the electrode device 10 from the electrical signal that has passed through the subject and is obtained via the electrode device 10. In other words, it is possible to obtain an electrical signal originating from the subject.

[0078] The electrical signal measurement system 100 of this embodiment includes an indentation pressure measurement unit 24 that measures the indentation pressure of each probe pin (unit probe pin 111) or each row of probe pins, and / or a unit measurement unit (unit current measurement unit 23) that measures the current flowing through the object T for each probe pin or each row of probe pins. The electrical signal measurement unit aggregates the measurement results of the unit measurement units. This makes it possible to obtain information (surface information) about the portion of the surface of the object T that is in contact with the electrode device 10. Therefore, by obtaining the surface information of the object T, it is possible to determine whether the measurement results of the overall current measurement unit 22 reflect the influence of the surface condition of the object T or the influence of the internal condition of the object T.

[0079] The electrical signal measurement system 100 of this embodiment includes wiring connected to the indentation pressure measurement unit 24 and / or the unit measurement unit (unit current measurement unit 23) for each probe pin (unit probe pin 111) or for each row of probe pins. The wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit. This makes it possible to easily obtain information (surface information) about the portion of the surface of the object T that is in contact with the electrode device 10.

[0080] The electrical signal measurement system 100 of this embodiment calculates the distribution of indentation pressure on the contact surface based on the measurement results of the indentation pressure measurement unit 24. And / or, the electrical signal measurement system 100 calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit (unit current measurement unit 23). The electrical signal measurement system 100 includes a correction unit (control unit 31) that corrects the measurement results of the electrical signal measurement unit (total current measurement unit 22) based on the distribution of indentation pressure and / or the area of ​​the contact surface. This makes it possible to remove the influence of the surface condition of the object T and obtain the current value of the electrical signal that has passed through the object with high accuracy.

[0081] The electrical signal measurement system 100 of this embodiment includes a penetration depth measurement unit that measures the penetration depth of each probe pin (unit probe pin 111) or each row of probe pins, and / or a unit measurement unit (unit current measurement unit 23) that measures the current flowing through the object T for each probe pin or each row of probe pins. The electrical signal measurement unit aggregates the measurement results of the unit measurement units. This makes it possible to obtain information (surface information) about the portion of the surface of the object T that is in contact with the electrode device 10. Therefore, by obtaining the surface information of the object T, it is possible to determine whether the measurement results of the overall current measurement unit 22 reflect the influence of the surface condition of the object T or the influence of the internal condition of the object T.

[0082] The electrical signal measurement system 100 of this embodiment includes wiring connected to a penetration depth measurement unit and / or a unit measurement unit (unit current measurement unit 23) for each probe pin (unit probe pin 111) or for each row of probe pins. The wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit. This makes it possible to easily obtain information (surface information) about the portion of the surface of the object T that is in contact with the electrode device 10.

[0083] The electrical signal measurement system 100 of this embodiment calculates the distribution of indentation depths on the contact surface based on the measurement results of the indentation depth measurement unit. And / or, the electrical signal measurement system 100 calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit (unit current measurement unit 23). The electrical signal measurement system 100 includes a correction unit (control unit 31) that corrects the measurement results of the electrical signal measurement unit (total current measurement unit 22) based on the distribution of indentation depths and / or the area of ​​the contact surface. This eliminates the influence of the surface condition of the target object T, making it possible to obtain with high accuracy the current value of the electrical signal that has passed through the target object.

[0084] Although the embodiments of the present disclosure have been described above, the description of the above-described embodiments is a preferred example of the present disclosure and is not limited thereto. For example, in the above-described embodiments, the present disclosure is applied to non-destructive testing of objects such as concrete structures and transportation equipment, but is not limited thereto. The present disclosure may also be applied to material evaluation, meat or processed food testing, agricultural product testing, live animal testing, etc.

[0085] In addition, the detailed configuration and operation of each device constituting the electrical signal measurement system can be modified as appropriate without departing from the spirit of the invention.

[0086] The present disclosure can be used for an electrode device for measuring an electrical signal and an electrical signal measurement system.

[0087] 100, 100b Electrical signal measurement system 10 Electrode device (electrode device for measuring electrical signals) 11 Probe pin section 111 Unit probe pin 12 Conductive sheet 13 Substrate 14 Metal plate 20 Measurement device 21 Signal generation section 22 Total current measurement section (electrical signal measurement section) 23 Unit current measurement section (unit measurement section) 24 Indentation pressure measurement section 30 Control device 31 Control section 32 Operation section 33 Display section 34 Communication section 35 Memory section 40 Plate-shaped electrode T Object Ta, Tb Measurement area

Claims

1. An electrode device for measuring electric signals that is connected to an electric signal measurement unit that measures the current flowing through an object by applying an electric signal to the object, comprising: a plurality of probe pins that are extendable and contractible along an axial direction; and a conductive sheet that is attached to the tips of the plurality of probe pins and forms a contact surface with the object, wherein the shape of the contact surface changes to follow the surface shape of the object.

2. The electrode device for measuring electrical signals according to claim 1, wherein the probe pins have a length that is not affected by noise from surrounding radio waves and are arranged in a matrix.

3. The electrode device for measuring electrical signals according to claim 1, wherein the conductive sheet is made of a flexible material.

4. An electrode device for measuring electrical signals as described in claim 1, further comprising a metal plate that covers the periphery of the probe pin and is expandable along the axial direction in accordance with the surface shape of the object, the metal plate being grounded.

5. An electric signal measurement system comprising at least one electrode device for measuring electric signals according to any one of claims 1 to 4 and the electric signal measurement unit, wherein the electric signal is any one of a DC signal, an AC signal, and a transient signal, and the electric signal measurement unit measures the current flowing in the object between a plurality of electrodes including the electrode device for measuring electric signals.

6. An electrical signal measurement system according to claim 5, further comprising a correction section that corrects the measurement results by removing signals due to the contact resistance of the electrode device for measuring electrical signals from the measurement results of the electrical signal measurement section through equivalent circuit analysis.

7. The electrical signal measurement system according to claim 5, further comprising a pressing pressure measurement unit that measures the pressing pressure of the probe pin for each of the probe pins or for each row of the probe pins, and / or a unit measurement unit that measures the current flowing through the object for each of the probe pins or for each row of the probe pins, wherein the electrical signal measurement unit aggregates the measurement results of the unit measurement units.

8. The electrical signal measurement system according to claim 7, further comprising wiring connected to the indentation pressure measurement unit and / or the unit measurement unit for each of the probe pins or each row of the probe pins, and the wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit.

9. An electrical signal measurement system as described in claim 7, further comprising a correction unit that calculates the distribution of the indentation pressure on the contact surface based on the measurement results of the indentation pressure measurement unit and / or calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit, and corrects the measurement results of the electrical signal measurement unit based on the distribution of the indentation pressure and / or the area of ​​the contact surface.

10. An electrical signal measurement system according to claim 5, comprising: a pressing depth measurement unit that measures the pressing depth of the probe pin for each of the probe pins or for each row of the probe pins; and / or a unit measurement unit that measures the current flowing through the object for each of the probe pins or for each row of the probe pins, wherein the electrical signal measurement unit aggregates the measurement results of the unit measurement units.

11. The electrical signal measurement system according to claim 10, further comprising wiring connected to the indentation depth measurement unit and / or the unit measurement unit for each of the probe pins or each row of the probe pins, and the wiring connected to the unit measurement units is collected and connected to the electrical signal measurement unit.

12. The electrical signal measurement system according to claim 10, further comprising a correction unit that calculates the distribution of the indentation depth on the contact surface based on the measurement results of the indentation depth measurement unit, and / or calculates the area of ​​the contact surface based on the measurement results of the unit measurement unit, and corrects the measurement results of the electrical signal measurement unit based on the distribution of the indentation depth and / or the area of ​​the contact surface.

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