JPH064659U - Electrode cell device for AC impedance measurement - Google Patents

Abstract

(57) [Abstract] [Purpose] To simplify the marking work on the metal plate surface and the positioning work of the electrode cell in the impedance measurement of the metal plate with the coating. [Structure] By arranging three electrode cells 6a, 6b, 6c in an outer cylinder 1 via an insulating member 2 and integrating them,
In the conventional AC impedance measurement of a metal plate coated with a coating, the complicated marking work on the metal plate surface and the positioning work of the electrode cells are reduced, and the measurement time can be shortened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an alternating current impedance measurement electrode cell device for measuring alternating current impedance of a metal plate on which a coating is applied.

[0002]

[Prior art]

 As a typical example, the conventional measurement of impedance of a metal plate coated with a coating will be described using a coated steel plate.

As shown in FIG. 2, the impedance of a conventional coated steel sheet is obtained by attaching an electrode cell composed of a counter electrode 30 and an electrolyte 40 to the surface of the coating film 20 and connecting a lead wire connected to the counter electrode 30 and the steel sheet 10 under the coating film. AC voltage 60 was applied to 50 and measured (single cell method). In addition, Fig. 3 shows the recently introduced double-cell method measurement. In this case, two electrode cells A and B having counter electrodes 30 and 31 are attached to the surface of the coating film 20, respectively. The alternating voltage 60 was applied between the counter electrodes 31, and it measured.

The electrolytes 40 and 41 in this case are generally pastes of an electrolyte prepared by dissolving 3% of carboxymethylcellulose in 3% saline, and are applied to the surface of the coating film 20. As 30, 31, aluminum foil (for example, length 50 × width 50 × thickness 0.03 mm) was used.

Further, a gel electrode cell is introduced in the utility model registration application No. 009556 in 1983.

[0006]

[Problems to be solved by the device]

 In the conventional impedance measurement using a single cell, the lead wire is connected to the coated steel plate as shown in Fig. 2. Therefore, there is a problem that part of the painted surface is damaged and connected in the measurement on a ship or the like. Also, drawing a lead wire from a distance made measurement difficult due to the inclusion of noise.

Further, in the case of the double cell method shown in FIG. 3 in which two cells are installed on the surface of a coated steel plate, there is a problem that correct measurement cannot be performed unless the impedances of the cells are equal.

That is, the impedance circuit of a coated steel sheet can be generally represented by an equivalent circuit consisting of a resistance R, a capacitance C, and a frequency f, and a real term R and an imaginary term −jX (where X = 1 / ωC, ω is an angular velocity and can be represented by 2πf).

When cells A and B are used, the impedances Z _A and Z _B between the cells A and B and the coated steel sheet and the combined impedance Z _AB are expressed by the following equations.

[0010] _{Z A = R A -jX A Z} B = R B -jX B Z A + Z B = (R A + R B) -j (X A + X B) = R AB -jX AB Accordingly, Z _A = Z If _{B, Z a, Z B =} R AB / 2-jX AB / 2 as the cell a, B of R, can be obtained X.

However, Z_A≠ Z_BIn the case of R_A≠ R_B, X_A≠ X_BTherefore, it is not possible to obtain each R and X. Therefore, the inventor does not need a lead wire, and _A ≠ Z_BIn this case, the triple cell method shown in Japanese Patent Application No. 137291 of 1985 was proposed as a measuring method. In this method, three cells A, B and C each having the structure shown in FIG. 5 are installed on the surface of a coated steel plate as shown in FIG. 4, and an impedance Z between the cells A, B and C is set._AB, Z_BC, Z_CARespectively, and the impedance Z of each cell A, B, C is measured based on these three sets of measured values._A, Z_B, Z_CIs calculated by the following equations (1) to (6).

Z _AB = (R _A + R _B ) −j (X _A + X _B ) ………………………… (1) Z _BC = (R _B + R _C ) −j (X _B + X _C ). ………………………… (2) Z _CA = ( _RC + _RA ) -j (X _C + X _A ) …………………… (3) Above (1) to (3) The following expressions (4) to (6) are obtained from the expression).

[0013] _{(Z AB -Z BC + Z CA} ) / 2 = R A -jX A ........................ (4) (Z BC -Z CA + Z AB) / 2 = R B -jX B ...... _{.................. (5) (Z CA -Z} AB + Z BC) / 2 = R C -jX C ........................ (6) above (4), (5), (6) The R and X of each cell A, B and C can be calculated by As the electrode cell at this time, three gel electrode cells proposed in utility model registration application No. 0095556 in 1983 were manufactured and used, but there were the following problems. (1) When there were many measurement points, the measurement of a certain point was completed, and the work of moving the three electrode cells to the next measuring point was complicated. (2) In addition, since the distance between each of the three electrode cells is maintained at a certain distance (for example, 20 mm) when moving, it is necessary to mark three points on the DUT in advance, which is complicated. there were.

The present invention is intended to solve the above problems.

[0015]

[Means for Solving the Problems]

 The electrode cell device for measuring AC impedance according to the present invention comprises three electrode cells each including a counter electrode, an electrolyte part, and an outer tube for the electrode cell, an outer tube in which the respective electrode cells are arranged, and an outer tube. It is characterized in that an insulating member provided between the cylinder and the electrode cell is provided.

[0016]

[Action]

 In the above, the impedance of the coated metal plate was measured by installing the device of this example on the surface of the metal plate and applying an AC voltage between the counter electrodes of the respective electrode cells. The impedance between them can be measured, and the impedance at the position where each counter electrode is placed can be obtained from the impedance between each counter electrode.

Further, in the device of the present invention, since the three electrode cells are integrated, the positioning can be easily performed on the metal plate surface.

[0018] As described above, the complicated marking work on the metal plate surface and electrode cell positioning work in the AC impedance measurement of the conventional coated metal plate are reduced, and the measurement time can be shortened. .

[0019]

【Example】

 One embodiment of the present invention is shown in FIGS. This embodiment shown in FIGS. 1 (a) and 1 (b) includes electrode cells 6a, 6b, 6c, and counter electrodes 5a, 5b, 5c, electrolyte members 4a, 4b, 4c, and outer cylinders 3a, 3b, 3c, respectively. The outer cylinder 1 in which the electrode cells 6a, 6b, 6c are arranged at regular intervals from each other, and the respective electrode cells provided between the outer cylinder 1 and the electrode cells 6a, 6b, 6c The insulating member 2 holding 6a, 6b, 6c is provided.

In the above description, the outer cylinder 1 is made of, for example, an acrylic resin pipe or the like, and has electrical insulation. The insulating member 2 is made of, for example, urethane foam or styrene foam. The outer cylinders 3a, 3b, 3c of the respective electrode cells 6a, 6b, 6c are, for example, vinyl chloride pipes or acrylic resin pipes cut into a required length, and have the same size. As the electrolyte members 4a, 4b, 4c, for example, an acrylic amide-based gel introduced in Japanese Utility Model Registration Application No. 0095556 in 1983 is used. The counter electrodes 5a, 5b, 5c are made of platinum, platinum-plated titanium stainless steel, or the like.

In this embodiment, since the three electrode cells 6a, 6b, 6c are integrated, it is possible to measure the impedance of the coated steel sheet by positioning once.

A measurement test performed by applying this embodiment will be described below. The test pieces were coated once on a blast steel plate of 150 x 70 x 3.2 mm with tar epoxy paint for ship ballast tanks by airless spray coating, left at room temperature and dried for 10 days, and then placed in natural seawater. It was soaked and pulled up from the sea about 4 years later. The dry film thickness of the test piece after coating and drying was 250 μm on average, and no rust or swelling was observed in the appearance of the test piece when it was pulled up from seawater.

As the electrode cell, one having three built-in cells each having a cell area of 35 cm ² (diameter of 6.7 cm) was used, and the electrode cell was placed on a coated steel plate and the impedance was measured. For reference, the impedance between one conventional cell and the steel plate shown in FIG. 2 was also measured.

The measurement results are shown in Tables 1 and 2. Table 1 shows measured values of R, jX, and tan δ at 1H _Z and 20H _Z measured by the conventional single cell method and this embodiment.

[0025]

[Table 1]

The values shown in the upper part of each column of Table 2 are measured values by the conventional single cell method, and the values in parentheses are calculated values based on the measured values by this embodiment.

[0027]

[Table 2]

From this table, the calculated values according to the present embodiment and the measured values according to the conventional single cell for R, jX, and tan δ of 1H _Z and 20H _Z were in good agreement, and the practicality was confirmed.

It was also confirmed that the cell movement and measurement at the time of measurement were easy. Due to the above, the complicated marking work on the steel plate surface and the positioning work of the electrode cell in the conventional AC impedance measurement of the coated steel plate are reduced, and the measurement time can be shortened.

[0030]

Effect of the Invention In the electrode cell device for measuring AC impedance of the present invention, three electrode cells are disposed in the outer cylinder via the insulating member and integrated, and thus the conventional coating is applied. In the AC impedance measurement of the metal plate, the complicated marking work on the metal plate surface and the positioning work of the electrode cell are reduced, and the measurement time can be shortened.

[Brief description of drawings]

1A and 1B are explanatory views of an embodiment of the present invention, in which FIG. 1A is a plan view and FIG.

FIG. 2 is an explanatory diagram of measurement by a conventional single cell method.

FIG. 3 is an explanatory diagram of measurement by a conventional double cell method.

FIG. 4 is an explanatory diagram of measurement by a conventional triple cell method.

FIG. 5 is an explanatory diagram of an electrode cell in the conventional triple cell system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 outer cylinder 2 insulating members 3a, 3b, 3c outer cylinders for electrode cells 4a, 4b, 4c electrolyte members 5a, 5b, 5c counter electrodes 6a, 6b, 6c electrode cells

Claims (1)

[Scope of utility model registration request] 1. Three electrode cells each comprising a counter electrode, an electrolyte member, and an electrode cell outer cylinder, an outer cylinder in which the respective electrode cells are disposed, and between the outer cylinder and the electrode cell. An electrode cell device for AC impedance measurement, comprising an insulating member provided.