Electric conductivity-measuring material, electric conductivity-measuring film, electric conductivity-measuring device, and electric conductivity-measuring method, as well as electric resistivity-measuring material, electric resistivity-measuring film, electric resistivity-measuring device, and electric resistivity-measuring method

Abstract

[Object] An electric conductivity-measuring material which emits light according to electric conductivity of a measurement object; an electric conductivity-measuring film containing the material; and an electric conductivity-measuring device and an electric conductivity-measuring method using the electric conductivity-measuring film are provided. An electric resistivity-measuring material which emits light according to electric resistivity of a measurement object when electrons are made incident; an electric resistivity-measuring film containing the material; and an electric resistivity-measuring device and an electric resistivity-measuring method using the electric resistivity-measuring film are also provided. [Solution] An electric conductivity-measuring material is used, which contains at least one of a fluorescent substance, a luminescent substance, an electroluminescent substance, a fractoluminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance and a mechanoluminescent substance.

Claims

1. An electric conductivity-measuring method for measuring electric conductivity of a surface or inside of a measurement object by measuring light emission from the surface of the measurement object, comprising steps of: forming the electric conductivity-measuring film containing at least one of a fluorescent substance, a luminescent substance, an electroluminescent substance, a fractoluminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance and a mechanoluminescent substance on the surface of the measurement object; and emitting charged particles toward the electric conductivity-measuring film; wherein volume resistivity or surface resistivity of the electric conductivity-measuring film is higher than volume resistivity or surface resistivity of the measurement object.

2. An electric conductivity-measuring method for measuring electric conductivity of a surface or inside of a measurement object by measuring light emission from the surface of the measurement object, comprising steps of: forming the electric conductivity-measuring film containing at least one of a fluorescent substance, a luminescent substance, an electroluminescent substance, a fractoluminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance and a mechanoluminescent substance on the surface of the measurement object; and emitting charged particles toward the electric conductivity-measuring film; wherein the mechanoluminescent substance is: a substance represented by SrAl.sub.2O.sub.4 which is doped with Eu.sup.2+; a substance represented by SrAl.sub.2O.sub.4 which is doped with at least one of Eu.sup.2+, Ho.sup.3+, Dy.sup.2+, M.sub.1, M.sub.2 and M.sub.3 (M.sub.1, M.sub.2, M.sub.3=monovalent to trivalent metal ions different from each other); or a substance represented by CaYAl.sub.3O.sub.7 which is doped with Eu.sup.2+.

3. An electric conductivity-measuring method for measuring electric conductivity of a surface or inside of a measurement object by measuring light emission from the surface of the measurement object, comprising steps of: forming the electric conductivity-measuring film containing at least one of a fluorescent substance, a luminescent substance, an electroluminescent substance, a fractoluminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance and a mechanoluminescent substance on the surface of the measurement object; emitting charged particles toward the electric conductivity-measuring film, wherein the charged particles have an energy ranging from 1 V/mm to 3000 V/mm; and applying voltage to the measurement object.

4. The electric conductivity-measuring method according to claim 3, wherein volume resistivity or surface resistivity of the electric conductivity-measuring film is higher than volume resistivity or surface resistivity of the measurement object.

5. The electric conductivity-measuring method according to claim 4, wherein the mechanoluminescent substance is: a substance represented by SrAl.sub.2O.sub.4 which is doped with Eu.sup.2+; a substance represented by SrAl.sub.2O.sub.4 which is doped with at least one of Eu.sup.2+, Ho.sup.3+, Dy.sup.2+, M.sub.1, M.sub.2 and M.sub.3 (M.sub.1, M.sub.2, M.sub.3=monovalent to trivalent metal ions different from each other); or a substance represented by CaYAl.sub.3O.sub.7 which is doped with Eu.sup.2+.

6. The electric conductivity-measuring method according to claim 1, wherein the charged particles have an energy ranging from 1 V/mm to 3000 V/mm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic perspective view of an electric conductivity-measuring device according to Embodiment 1.

(2) FIG. 2 is an operation flowchart of the electric conductivity-measuring device according to Embodiment 1.

(3) FIG. 3 is a photograph of a surface of a polylactic acid sheet (measurement object) of Example 1 on which a plurality of silver nanoink lines are formed.

(4) FIG. 4 is a photograph in which an electric conductivity-measuring sheet is placed on the measurement object of Example 1.

(5) FIG. 5 is a photograph in which the measurement object of Example 1 is irradiated with charged particles.

(6) FIG. 6 is a photograph in which an electric conductivity-measuring sheet is placed on a measurement object of Example 2.

(7) FIG. 7 is a photograph just after the measurement object of Example 2 was irradiated with charged particles.

(8) FIG. 8 is a photograph after a while since the measurement object of Example 2 was irradiated with the charged particles.

(9) FIG. 9 is a photograph of a surface of an antistatic plastic sheet (measurement object) of Example 3.

(10) FIG. 10 is a photograph just after the measurement object of Example 3 was irradiated with charged particles.

(11) FIG. 11 is a photograph after a while since the measurement object of Example 3 was irradiated with the charged particles.

(12) FIG. 12 is a photograph of a surface of an antistatic plastic sheet (measurement object) of Example 4.

(13) FIG. 13 is a photograph just after the measurement object of Example 4 was irradiated with charged particles.

(14) FIG. 14 is a photograph after a while since the measurement object of Example 4 was irradiated with the charged particles.

(15) FIG. 15 is a photograph of a surface of a carbon fiber-reinforced plastic (measurement object) of Example 5.

(16) FIG. 16 is a photograph in which an electric conductivity-measuring film is pasted on the measurement object of Example 5.

(17) FIG. 17 is a photograph in which the measurement object of Example 5 is irradiated with charged particles.

(18) FIG. 18 is a schematic perspective view of an electric conductivity-measuring device according to Embodiment 2.

DESCRIPTION OF EMBODIMENTS

(19) Embodiments of an electric conductivity-measuring material, an electric conductivity-measuring film using the material, and an electric conductivity-measuring device using the electric conductivity-measuring film according to the present invention will be explained below with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments.

Embodiment 1

(20) FIG. 1 illustrates a schematic perspective view of an electric conductivity-measuring device according to Embodiment 1. As illustrated in this figure, in an electric conductivity-measuring device 1 according to Embodiment 1, an electric conductivity-measuring film 11 is formed throughout a surface of a rectangular flat measurement object 10, the electric conductivity-measuring film 11 containing at least one of an fluorescent substance, a luminescent substance, an electroluminescent substance, a breaking luminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance, and a mechanoluminescent substance.

(21) In addition, cylindrical charged particle-emitting unit 20 having a taper-shaped tip portion is fixed above the electric conductivity-measuring film 11 by a jig (not shown) so that the electric conductivity-measuring film 11 can be irradiated with charged particles. Specifically, when an electric field (or voltage) is applied between a charged particle-emitting unit and the measurement object 10, charged particles (e.g., N.sup.+, N.sup.−, O.sup.2−, H.sup.+, electrons, or the like) generated by ionization of gases present in the vicinity of the charged particle-emitting unit are emitted toward the electric conductivity-measuring film 11.

(22) Furthermore, a camera (not shown) as a recording unit for recording a luminescence state of the electric conductivity-measuring film 11 is fixed above the measurement object 10 with a jig (not shown) so that the luminescence state of the electric conductivity-measuring film 11 can be recorded.

(23) Herein, the electric conductivity-measuring film 11 is not particularly limited as long as it is composed of a material containing at least one type of the aforementioned substances. A thickness of the electric conductivity-measuring film 11 is not particularly limited, but the thickness is preferably within a range of 1 μm to 1 mm, more preferably a range of 10 μm to 500 μm from the viewpoint of luminance and handling ease.

(24) The electric conductivity-measuring film 11 may include, for example: a film manufactured by homogeneously mixing an epoxy resin or an urethane resin, a curing agent and a solvent for controlling crosslinking/curing reaction of these resins, the above-described substances, and a dispersant/auxiliary agent for homogeneously dispersing the substances, and applying/curing this mixture on the surface of the measurement object 10; and non-woven fabric, paper, or other cloth-like members composed of polyester, nylon, acryl, cellulose or the like in which the above-described substances are dispersed. The electric conductivity-measuring film manufactured as above may be directly formed on a surface of the measurement object, or the separately manufactured electric conductivity-measuring film 11 may be attached to the surface of the measurement object.

(25) Note that the concentration (total weight ratio) of the above-described substances contained in the electric conductivity-measuring film 11 is not particularly limited, but a range of 20 wt % to 80 wt % is preferable because light emission can be visually confirmed, and a range of 50 wt % to 70 wt % is more preferable because light emission can be visually confirmed more obviously.

(26) In addition, the charged particle-emitting unit 20 is not particularly limited as long as it can emit the charged particle, but preferably, it can emit the charged particle having an energy ranging from 1 V/mm to 3000 V/mm, and particularly preferably, it can emit the charged particle having an energy ranging from 22 V/mm to 1000V/mm.

(27) Next, an operation of the electric conductivity-measuring device 1 (electric conductivity-measuring method) according to Embodiment 1 will be explained. FIG. 2 is an operation flowchart of the electric conductivity-measuring device according to Embodiment 1.

(28) First, the electric conductivity-measuring film 11 is formed on the surface of the measurement object 10 (S1). Then, charged particles are emitted from a charged particle-emitting unit 20 (S2).

(29) Then, the electric conductivity-measuring film 11 emits light according to electric conductivity of a surface or inside of the measurement object 10 in contact with the film 11. That is, the electric conductivity-measuring film 11 emits light corresponding to electric conductivity distribution of the surface or inside of the measurement object 10. Also, luminance of the electric conductivity-measuring film 11 which emits light at this time is increased according to the magnitude of the electric conductivity of the measurement object 10 corresponding to a portion which emits light. Furthermore, the speed of the light emission of the electric conductivity-measuring film 11 is also increased according to the magnitude of the electric conductivity of the measurement object 10 corresponding to a portion that emits light. In addition, the moving speed (propagation speed) of the portion that emits light is increased according to the magnitude of the electric conductivity of the measurement object 10 corresponding to the portion that emits light.

(30) Then, the luminescence state is photographed by a camera disposed above the measurement object 10 (S3).

(31) Note that the electric conductivity of the measurement object 10 can be calculated on the basis of the light-emission (luminance) data of the electric conductivity-measuring film 11 obtained as above. Specifically, calibration curves of the luminance and the electric conductivity of electric conductivity-measuring film 11 are prepared in advance, for example. The, electric conductivity (electric conductivity distribution) of each portion (area) of the surface of the measurement object can be calculated from these calibration curves and the luminance.

(32) As described above, local electric conductivity (electric conductivity distribution) of the measurement object 10 can be measured by the electric conductivity-measuring method and the electric conductivity-measuring device 1 according to this embodiment.

(33) Also, the electric conductivity-measuring method and the electric conductivity-measuring device 1 according to this embodiment do not require the direct application of voltage to the measurement object 10, so that the electric conductivity can be measured regardless of the size, shape, and the like of the measurement object.

(34) Furthermore, in the electric conductivity-measuring method and the electric conductivity-measuring device 1 according to this embodiment, the magnitude of the luminance of the electric conductivity-measuring film 11 represents the magnitude of the electric conductivity. Therefore, the electric conductivity (electric conductivity distribution) of the measurement object 10 can be intuitively understood, which cannot be achieved by the conventional measuring methods.

(35) Also, measurement object 10 is irradiated with the charged particles, a portion of the electric conductivity-measuring film 11 located just below the charged particle-emitting unit 20 emits light first, and then, portions around the certain portion begin to emit light and luminance of the certain portion that has emitted light first is gradually lowered with the lapse of time. Such a phenomenon occurs repeatedly, so that it looks as if the light is moving (being propagated) as a ring of light is spreading. The moving speed (propagation speed) of the light-emitting portion is increased according to electric conductivity of a part and its surroundings on the surface or inside of the measurement object 10 in contact with the light-emitting portion.

(36) Therefore, calibration curves of the moving speed and electric conductivity of the light-emitting portion are prepared in advance, and the electric conductivity (electric conductivity distribution) of the surface of the measurement object 10 corresponding to the light-emitting portion can be calculated from these calibration curves and the moving speed of the light-emitting portion that have been actually measured.

(37) Note that, although the electric conductivity-measuring device 1 is configured using one charged particle-emitting unit 20 in this embodiment, the present invention is not limited thereto. The electric conductivity-measuring device including a plurality of the charged particle-emitting units may be configured so as to uniformly irradiate the electric conductivity-measuring film 11 formed on the measurement object 10 with the charged particles. This configuration allows the electric conductivity-measuring film 11 to be uniformly irradiated with the charged particles so that the electric conductivity (electric conductivity distribution) of the measurement object 10 can be measured with higher accuracy.

(38) Note that the electric conductivity is the reciprocal of the electric resistivity. Therefore, when the electric conductivity-measuring film 11 of this embodiment is replaced by an electric resistivity-measuring film, electric resistivity (electric resistivity distribution) of the measurement object 10 can also be measured in a similar manner to the electric conductivity (electric conductivity distribution).

Example 1

(39) As shown in FIG. 3, a plurality of silver nanoink lines were formed on a polylactic acid sheet (PLA sheet) by using silver ink (DGP-NO, from Advanced Nano Products Co., Ltd). Then, a PLA sheet 50 on which the silver nanoink lines 51 were formed in a stripe shape was made as a measurement object.

(40) Then, an electric conductivity-measuring film, i.e., non-woven fabric (electric conductivity-measuring sheet 53) into which SrAl.sub.2O.sub.4:Eu.sup.2+ was kneaded was placed on this PLA sheet 50. Next, as shown in FIG. 4, an electrode 55 as a charged particle-emitting unit was placed above the non-woven fabric (distance: 10 mm).

(41) Thereafter, the measurement object was irradiated with charged particle by applying DC voltage of 3 kV and 1 μA to the electrode 55 to cause corona discharge, the result being shown in FIG. 5. Here, electric conductivity of the PLA sheet is 1.00×10.sup.−15 Ω.sup.−1.Math.m.sup.−1 or more, and electric conductivity of the silver nanoink lines is 1.68×10.sup.−2 Ω.sup.−1.Math.m.sup.−1.

(42) As shown in FIG. 5, it was found that portions consisting of the silver nanoink lines having higher electric conductivity had higher luminance than portions consisting of polylactic acid. That is, it was found that, by irradiating the electric conductivity-measuring film with the charged particles to cause light emission, portions in the measurement object where electricity flowed relatively easily could be measured, and furthermore, relative electric conductivity distribution of the measurement object could be measured using calibration curves and the like.

Example 2

(43) As shown in FIG. 6, an electric conductivity-measuring film, i.e., non-woven fabric (electric conductivity-measuring sheet) into which SrAl.sub.2O.sub.4:Eu.sup.2+ was kneaded was placed on a packaging box (measurement object) with characters and the like printed on it. Here, portions with characters printed have higher electric conductivity than portions without characters printed.

(44) Then, as in Example 1, the measurement object was irradiated with charged particle by applying voltage/current (3 k, 1 μA) to an electrode located above (distance: 10 mm) to cause corona discharge. The results are shown in FIGS. 7 and 8. FIG. 7 is a photograph just after the measurement objectwas irradiated with charged particles, and FIG. 8 is a photograph after a while since the measurement object was irradiated with the charged particles.

(45) As can be seen from these figures, portions of the electric conductivity-measuring film corresponding to the printed characters and the like momentarily emitted light along the characters and the like (emitted light as if the light was moving along the characters and the like) in a stage of starting irradiation with the charged particle, and other portions slowly began to emit light (emitted light as if the light was slowly moving) with the lapse of time, so that finally the whole electric conductivity-measuring film emitted light. In addition, the portions of the electric conductivity-measuring film corresponding to the characters and the like had higher light emission intensity than other portions.

(46) From the above, it was found that, by irradiating the electric conductivity-measuring film with the charged particles to cause light emission, relative electric conductivity distribution of the measurement object could be grasped, and by measuring the moving speed of the portions that emit light (light-emitting portions), electric conductivity (electric conductivity distribution) of the surface of the measurement object corresponding to the light-emitting portion could be easily measured using calibration curves and the like.

Example 3

(47) An electric conductivity-measuring sheet as in Example 2 was placed on a surface of a measurement object, i.e., an antistatic plastic sheet (Achilles Seiden F (Both Sides Printed) from Achilles Corporation) shown in FIG. 9 which included conductive wires formed in a lattice shape in the vicinity of the both surface thereof. Here, the conductive wires have higher electric conductivity than plastic.

(48) Then, as in Example 2, a central portion of the measurement object was irradiated with charged particle by applying DC voltage of 3 kV and 1 μA to an electrode located above (distance: 10 mm) to cause corona discharge. The results are shown in FIGS. 10 and 11.

(49) As can be seen from these figures, portions of the electric conductivity-measuring film corresponding to the conductive wires near immediately below the voltage-applied electrode (including not only the conductive wires in the vicinity of the surface on which the electric conductivity-measuring film was formed, but also the conductive wires the conductive wires in the vicinity of the opposite surface (i.e., inside of the measurement object)) momentarily emitted light in a stage of starting irradiation with the charged particle, and portions of the electric conductivity-measuring film corresponding to other portions of the conductive wires (i.e., portions that had not emitted light in the stage of starting irradiation with the charged particle) quickly emitted light (emitted light as if the light was quickly moving) with the lapse of time. It was also found that portions corresponding to the plastic portions without the conductive wires slowly began to emit light (emitted light as if the light was slowly moving) with the further lapse of time. In addition, the portions of the electric conductivity-measuring film corresponding to the conductive wires had higher light emission intensity (luminance) than the plastic portions without the conductive wires.

(50) Also from the above, it was found that, by irradiating the electric conductivity-measuring film with the charged particles to cause light emission, relative electric conductivity distribution of a surface and inside of the measurement object could be grasped, and by measuring the time to light emission and the moving speed of the portions that emit light (light-emitting portions), electric conductivity (electric conductivity distribution) of the surface of the measurement object corresponding to the light-emitting portion can be easily measured using calibration curves and the like.

Example 4

(51) An electric conductivity-measuring sheet as in Example 2 was placed on a surface of a measurement object, i.e., a Ply Canvas E-3000TFW (from Ishizuka Corporation. Inc.) shown in FIG. 12 on which a lattice-shaped mesh was formed. Here, polyester yarn constituting the mesh has higher electric conductivity than a transparent film made from polyvinylchloride.

(52) Then, as in Example 2, a portion of the measurement object was irradiated with charged particle by applying DC voltage of 3 kV and 1 μA to an electrode located above (distance: 10 mm) to cause corona discharge. The results are shown in FIGS. 13 and 14.

(53) As can be seen from these figures, lattice-shaped portions of the electric conductivity-measuring sheet corresponding to the lattice-shaped mesh momentarily emitted light in a stage of starting irradiation with the charged particle, and portions of the electric conductivity-measuring sheet corresponding to other portions of the mesh (i.e., portions that had not emitted light in the stage of starting irradiation with the charged particle) quickly emitted light (emitted light as if the light was quickly moving) with the lapse of time. It was also found that portions corresponding to the transparent film without the mesh slowly began to emit light (emitted light as if the light was slowly moving) after the further lapse of time. In addition, the portions of the electric conductivity-measuring film corresponding to the mesh had higher light emission intensity (luminance) than the transparent film without the mesh.

(54) Also from the above, it was found that, by irradiating the electric conductivity-measuring film with the charged particles to cause light emission, relative electric conductivity distribution of the measurement object could be grasped, and by measuring the time to light emission and the moving speed of the portions that emit light (light-emitting portions), electric conductivity (electric conductivity distribution) of the surface of the measurement object corresponding to the light-emitting portion could be easily measured using calibration curves and the like.

Example 5

(55) A mechanoluminescent substance, i.e., a mixture of SrAl.sub.2O.sub.4:Eu.sup.2+ and photocurable acrylic resin (from Microjet Corporation) (weight proportion of SrAl.sub.2O.sub.4:Eu.sup.2+: 70%) was applied on a carbon fiber-reinforced plastic (CF/PA66, from Bond-Laminates) shown in FIG. 15 and cured so as to form an electric conductivity-measuring film (with a thickness of about 100 μm) shown in FIG. 16. Note that a portion enclosed by a circle is a portion to be irradiated with charged particles.

(56) Here, a surface of the carbon fiber-reinforced plastic is made of an insulating material, and carbon fibers as a conducting material are kneaded into the inside thereof. Note that, among rectangular portions constituting the carbon fiber-reinforced plastic, portions having a vertically-arranged longitudinal direction have a configuration with higher electric conductivity than portions having a horizontally-arranged longitudinal direction.

(57) Then, as in Example 2, a portion enclosed by a circle of the measurement object was irradiated with charged particle by applying DC voltage of 3 kV and 1 μA to an electrode located above (distance: 10 mm) to cause corona discharge. The result is shown in FIG. 17.

(58) As can be seen from this figure, the portions into which carbon fibers were kneaded emitted light. It was found that, within this portion, an inner portion with higher electric conductivity emitted stronger light (light with higher luminance) than other portions.

(59) Also from the above, it was found that, by irradiating the electric conductivity-measuring film with the charged particles to cause light emission, relative electric conductivity distribution of the inside of the measurement object could be easily measured.

Embodiment 2

(60) In Embodiment 1, the measurement object provided with the electric conductivity-measuring film on its surface was irradiated with the charged particle from the charged particle-emitting unit located above to cause the light emission of the electric conductivity-measuring film, and thereby the electric conductivity (electric conductivity distribution) of the measurement object was measured. However, the present invention is not limited thereto.

(61) For example, voltage may be directly applied to the measurement object including the electric conductivity-measuring film formed on its surface to cause the light emission of the electric conductivity-measuring film, and thereby the electric conductivity (electric conductivity distribution) of the measurement object may be measured.

(62) Specifically, as shown in FIG. 18, for a measurement object 10 including an electric conductivity-measuring film 11 formed on its one surface, an electrode 15 is provided over the other surface of the measurement object 10 via an insulating film 17. Note that the electrode 15 is connected to a power source (not shown). Also, in this embodiment, the electrode 15 and the power source constitute a voltage application means.

(63) Here, the electrode 15 and the power source are not specifically limited as long as they can cause the light emission of the electric conductivity-measuring film 11 when voltage is applied thereto. A connecting position of the electrode to the measurement object 10 is also not specifically limited, and the electrode may be connected to the electric conductivity-measuring film 11. Furthermore, the voltage applied to the electrode 15 is also not specifically limited, and DC voltage, AC voltage, pulse voltage, and the like can be used. In addition, the insulating film 17 is also specifically limited as long as it can prevent the movement of charge from the electrode 15 to the measurement object 10.

(64) Then, as in Embodiment 1, the electric conductivity-measuring film emits light corresponding to electric conductivity distribution of the surface or inside of the measurement object 10 when voltage is applied to the electrode 15. Also, luminance of the electric conductivity-measuring film which emits light at this time is increased according to the magnitude of the electric conductivity of the measurement object in the vicinity thereof.

(65) Therefore, as in Embodiment 1, local electric conductivity (electric conductivity distribution) of the measurement object 10 can be measured, and by measuring the moving speed of the light-emitting portions, electric conductivity (electric conductivity distribution) of the surface of the measurement object 10 corresponding to the light-emitting portion can be easily measured.

(66) Also, although the voltage application means is constituted by the electrode 15 and the power source, the voltage application means is not specifically limited as long as it can apply voltage to the measurement object 10. For other voltage application means: the power source may be directly connected to the measurement object so that the charged particle-emitting unit described in Embodiment 1 is in contact with the measurement object; or voltage may applied to the measurement object due to contact charging, peeling charging, friction charging, or the like.

(67) Note that the electric conductivity is the reciprocal of the, electric resistivity. Therefore, when the electric conductivity-measuring film 11 of this embodiment is replaced by an electric resistivity-measuring film, electric resistivity (electric resistivity distribution) of the measurement object 10 can also be measured using calibration curves and the like in a similar manner to Embodiment 1.

Other Embodiments

(68) In the aforementioned embodiments, a solid was used as the measurement object. However, the measurement object to which the present invention can be applied is not limited thereto. The present invention can be applied to substances other than solid substances such as liquids and gel substances as the measurement object.

(69) Note that, although the camera as the recording unit was installed so as to record the luminescence state of the electric conductivity-measuring film in the aforementioned embodiments, it is needless to say that the luminescence state of the electric conductivity-measuring film can be observed with naked eyes without installing a camera.

REFERENCE NUMERALS

(70) 1, 1A electric conductivity-measuring device 10 measurement object 11 electric conductivity-measuring film 15, 55 electrode 17 insulating film 20 charged particle-emitting unit 50 PLA sheet 51 silver nanoink line 53 electric conductivity-measuring sheet