Resistance testing device and method

Abstract

The present application relates to a resistance testing device and method, which is suitable for resistance measurement of hollow cylinders such as ammunition packaging cylinders, and the resistance testing device comprises a first air cushion body which can be inflated and deflated to change the volume, a first electrode and a second electrode which are arranged in parallel on the outer surface of the first air cushion body at a predetermined interval, and a third electrode, the outer surface of which is an electrode, and the third electrode can be inflated and deflated to change the volume. The present application adopts air cushion electrodes, and the volume is self-adaptive after being inflated and deflated, so that the electrodes are tightly and pressurizedly contacted on the surface of the measured object, thereby effectively realizing surface resistance measurement of hollow cylinders such as ammunition packaging cylinders.

Description

Technical Field

[0001] This invention relates to the field of electrostatic testing, and more specifically to a resistance testing device and method. Background Technology

[0002] Ammunition packaging cartridges are crucial safety protection equipment during ammunition storage and transportation. With the increasing use of electronic components and electro-pyrotechnics in ammunition, the electrostatic sensitivity of ammunition equipment is increasing, while its anti-static performance is weakening. Ammunition equipment is diverse, and the storage and transportation environment is complex. During production, storage, transportation, and use, static electricity can accumulate due to friction, impact, contact, and separation, leading to electrostatic discharge. This can cause weapon systems to lose combat capability or even burn and explode, resulting in incalculable losses.

[0003] Ammunition packaging cartridges are containers for holding and protecting ammunition. Early ammunition packaging mainly used materials such as high-pressure polyethylene plastic and fiberglass, whose resistivity is generally (10 Ω·cm). 12 ~10 17 Between 100 Ω·m, static electricity easily accumulates and discharges. During ammunition technical maintenance, the ammunition body and packaging canister can carry a static potential of thousands of volts. When electrostatic discharge occurs, a high discharge current is generated instantaneously, and even spark discharge may occur. For ammunition, this may cause accidental ignition of electro-pneumatic devices, or even directly cause the detonation of explosives. As an important safety protection equipment in the ammunition storage and transportation process, the surface resistivity performance of ammunition packaging canisters is clearly required in the national standard GB 12158-2006 "General Guidelines for the Prevention of Static Electricity Accidents" and the national military standard GJB 2527 "Requirements for Antistatic Performance of Ammunition". However, due to the material properties and special structure such as cylindrical shape of ammunition packaging canisters, existing methods have serious shortcomings, resulting in test results that cannot accurately reflect the antistatic performance of ammunition packaging canisters, creating a major hidden danger.

[0004] Currently, China's anti-static material resistance testing equipment mainly targets planar materials, such as anti-static shielded packaging bags, anti-static desktops, tables, and mats. However, ammunition packaging tubes are made of materials such as ABS plastic and glass with anti-static coatings on both the inner and outer surfaces, and are usually cylindrical. Commonly used surface resistance measurement equipment is mainly divided into two types: parallel electrodes and circular test electrodes (also known as weights).

[0005] like Figure 1 The diagram shows a parallel test electrode. The relationship between electrode size and resistivity is as follows:

[0006]

[0007] It is worth noting that in the above formula, regardless of the symbols used, or the dimensions and units, ρ s All are related to surface resistivity R sThe same, but its physical meaning has changed, ρ s The value is a comprehensive evaluation of the surface conductivity and volume conductivity of the tested material.

[0008] like Figure 2 The diagram shows a circular test electrode (also known as a weighted electrode). A traditional weighted circular test electrode weighs 2.27 kg ± 0.06 kg and has a diameter of 63.5 mm ± 0.25 mm. This type of electrode is frequently used to test the resistance of equipment and facilities such as antistatic flooring, antistatic workbenches, antistatic shoes, antistatic clothing, and antistatic work chairs.

[0009] The parallel electrode and weighted electrode tests described above are both two-electrode tests, and the test results cannot be used to separately determine volume resistivity or surface resistivity; they can only assess the electrostatic leakage resistance of the ammunition packaging cartridge. However, if the surface resistivity of the inner and outer surfaces of the ammunition packaging cartridge is required, neither of the above two measurement methods can meet the testing requirements.

[0010] Furthermore, both parallel and circular electrodes, based on their shape, cannot make good contact with the inner or outer surface of the ammunition packaging cartridge, making it impossible to accurately measure its surface leakage resistance. Since ammunition packaging cartridges vary in diameter, a parallel or circular test electrode suitable for one size cannot be used for other sizes. Therefore, both parallel electrode and circular test electrode (also known as a weighted test) methods have limitations in testing the antistatic performance of ammunition packaging cartridges. Summary of the Invention

[0011] As mentioned above, there are significant limitations in the current electrostatic testing of ammunition packaging canisters. To address these issues, this invention proposes a resistance testing device and method. Addressing the challenges in designing surface resistance testing electrodes for hollow cylinders such as ammunition packaging canisters, an air-cushion electrode is proposed. The air cushion is inflated using an air pump, and the inflation pressure can be measured in real time, ensuring that the metal testing electrode for measuring surface resistance is in close contact with the surface of the ammunition packaging canister.

[0012] In a first aspect, embodiments of the present invention provide a resistance testing device, the resistance testing device comprising:

[0013] A first air cushion that can be inflated and deflated to change its volume;

[0014] The first electrode and the second electrode are arranged parallel to each other on the outer surface of the first air cushion body at a predetermined interval; and

[0015] The third electrode has an outer surface that is an electrode, and the third electrode can be filled and released to change its volume.

[0016] Furthermore, the outer surface of the first air cushion is covered with a dielectric film material as a substrate.

[0017] Furthermore, both the first electrode and the second electrode are metal film materials disposed on the dielectric film material.

[0018] Furthermore, the resistivity of the dielectric film material is higher than 10. 14 Ω;

[0019] The resistivity of the metal film material is less than 10. 3 Ω.

[0020] Furthermore, the inner liner of the third electrode is an air cushion that can be inflated and deflated to change its volume, and the outer surface of the third electrode is covered with a flexible metallic material as an electrode.

[0021] In a second aspect, embodiments of the present invention provide a resistance testing method, utilizing the resistance testing apparatus as described in any one of the first aspects, characterized in that the resistance testing method includes:

[0022] Test the resistance of the outer or inner surface of a hollow cylinder.

[0023] Further, the surface resistance of the hollow cylinder is tested, including:

[0024] The first air cushion body is wrapped around the outer surface of the hollow cylinder, and the first electrode and the second electrode on the first air cushion body are located on the inner side;

[0025] The third electrode is inserted into the hollow cylinder;

[0026] Inflate the first air cushion until it completely covers the outer surface of the hollow cylinder, and both the first electrode and the second electrode are in contact with the outer surface of the hollow cylinder.

[0027] The third electrode is inflated until the outer surface of the third electrode fills the inner surface of the hollow cylinder.

[0028] The outer surface resistance of the hollow cylinder is determined by measuring the first electrode, the second electrode, and the third electrode.

[0029] Further, the internal surface resistance of the hollow cylinder is tested, including:

[0030] The third electrode is wrapped around the outer surface of the hollow cylinder;

[0031] The first air cushion body is inserted into the hollow cylinder;

[0032] Inflate the third electrode until it completely covers the outer surface of the hollow cylinder;

[0033] Inflate the first air cushion until the outer surface of the first air cushion fills the inner surface of the hollow cylinder;

[0034] The inner surface resistance of the hollow cylinder is determined by measuring the first electrode, the second electrode, and the third electrode.

[0035] Furthermore, the first electrode, the second electrode, and the third electrode are all connected to test lines by welding, and the test lines are further connected to an electrostatic surface resistance tester.

[0036] Furthermore, the lengths of the first electrode and the second electrode are fixed, and the distance between the first electrode and the second electrode is fixed.

[0037] The resistance testing device and method of this invention employs an air-cushion electrode. The first and second electrodes are metal film materials arranged parallel to each other on the air cushion body at a certain distance. The third electrode is a structure with a flexible metal material on the outer surface and an inflatable and deflated interior. The metal material on the outer surface of the third electrode can serve as an electrode as a whole. The air cushion body is inflated by an air pump, so that each electrode can be tightly attached to the inner and outer surfaces of the ammunition packaging tube, and the inflation pressure can be measured in real time without breaking the inflatable structure. This enables the electrostatic measurement of the surface of hollow cylinders such as ammunition packaging tubes. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of parallel test electrodes in the prior art;

[0040] Figure 2 This is a schematic diagram of a circular test electrode in the prior art;

[0041] Figure 3 This is a schematic diagram of the first air cushion of the resistance testing device according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the third electrode of the resistance testing device according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of a product used for resistance testing according to an embodiment of the present invention;

[0044] Figure 6 This is a cross-sectional schematic diagram of the resistance testing device in the test state according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures:

[0046] First air cushion 1; first electrode 2; second electrode 3; third electrode 4; hollow cylinder 5. Detailed Implementation

[0047] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0048] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0049] like Figure 3 and Figure 4 The diagram illustrates a resistance testing device according to an embodiment of the present invention. The device includes a first air cushion 1, a first electrode 2 and a second electrode 3 disposed on the first air cushion 1, and a third electrode 4. The first air cushion 1 is inflatable and deflatable, causing its volume to change. The first electrode 2 and the third electrode 3 are arranged parallel to each other on the first air cushion 1 at a certain distance using a metal film material (such as strips or sheets). The inner lining of the third electrode 4 is an inflatable and deflatable air cushion structure, and the outer surface of the third electrode 4 is a flexible metal material, which can serve as an electrode. By inflating and deflating the air cushion, it can be tightly fitted to the inner and outer surfaces of a hollow cylinder, such as an ammunition packaging tube, and the electrode also makes close contact with the surface of the ammunition packaging tube, thereby achieving electrostatic testing.

[0050] In this embodiment, the outer surface of the first air cushion 1 is lined with a dielectric film material, and the first electrode 2 and the second electrode 3 are disposed on the dielectric film material, thereby making the outer surface of the first air cushion 1 insulated except for the first electrode 2 and the second electrode 3. The lower limit of the surface resistivity of the ammunition packaging cartridge is generally 10. 5 For requirements above Ω, the contact resistance between the test electrode and the sample should be designed to be less than 10Ω. 3 Ω, to meet accuracy requirements, with an impact of no more than 1%. Considering the mechanical and electrical properties of the electrodes, electrodes with good conductivity and a resistance value below 10Ω were selected. 3A metal film cloth material with a resistivity of Ω is used as the first electrode 2 and the second electrode 3, and the length and spacing of the first electrode 2 and the second electrode 3 are fixed values. 14 The dielectric film material of Ω is used as the substrate material of the first air cushion 1, and is processed to form such a shape. Figure 3 The flexible measurement structure of the first air cushion 1 shown is applicable to testing ammunition cartridges of different sizes. By wrapping the ammunition cartridge and then inflating it, it is ensured that the first electrode 2 and the second electrode 3 can achieve tight and pressurized contact with the surface of the ammunition cartridge. The outer surface of the third electrode 4 is entirely made of a flexible metallic material with conductive properties, and the inner liner of the third electrode 4 is also an inflatable and deflated structure. Inflation allows the flexible metallic material on the outer surface of the third electrode 4 to achieve tight and pressurized contact with the surface of the ammunition cartridge. Furthermore, it should be noted that the volume and shape of the first air cushion 1 and the third electrode 4 are not necessarily the same. Figure 3 and Figure 4 For illustrative purposes only, the volume and shape of the first air cushion 1 and the third electrode 4 can be adjusted according to the volume of the product to be tested.

[0051] like Figure 5 and Figure 6 As shown, this embodiment of the invention also provides a resistance testing method using the above-described resistance testing device, which can be used to test the outer or inner surface resistance of hollow cylinders such as ammunition packaging tubes, wherein the product to be tested is illustrated as a hollow cylinder 5, as shown in the figure. Figure 5 As shown, the hollow cylinder 5 includes an outer surface A and an inner surface B.

[0052] ① Testing the surface resistance of a hollow cylinder, including:

[0053] The first air cushion 1 is wrapped around the outer surface A of the hollow cylinder 5, and the first electrode 2 and the second electrode 3 on the first air cushion 1 are located on the inner side, that is, the first electrode 2 and the second electrode 3 face the outer surface A of the hollow cylinder 5.

[0054] Insert the third electrode 4 into the hollow cylinder;

[0055] Inflate the first air cushion 1 until it completely covers the outer surface A of the hollow cylinder 5 (i.e., it is fully wrapped around the outer surface A of the hollow cylinder 5). Secure the inflated first air cushion 1 to the hollow cylinder 5 using ropes or straps. The first electrode 2 and the second electrode 3 located inside the first air cushion 1 can be in close and pressurized contact with the outer surface A of the hollow cylinder 5.

[0056] Inflate the third electrode 4 until the outer surface of the third electrode 4 completely fills the inner surface B of the hollow cylinder 5 (that is, it completely covers and fills the inner surface B of the hollow cylinder 5).

[0057] The outer surface resistance of the hollow cylinder 5 is determined by measuring the first electrode 2, the second electrode 3, and the third electrode 4. This outer surface resistance is determined by the voltage applied between the first electrode 2 and the second electrode 3 and the current between the first electrode 2 and the second electrode 3 on the outer surface of the hollow cylinder 5.

[0058] Furthermore, it should be noted that the first electrode 2, the second electrode 3, and the third electrode 4 are all connected by test leads (not shown) via welding. These test leads are further connected to an electrostatic surface resistance tester (not shown), thereby enabling electrostatic measurement. Inevitably, the test leads will partially fall within the gap between the first air cushion 1 or the third electrode 4 and the hollow cylinder 5. However, since the air cushion is inflated, a tight fit can still be achieved, which will not affect the test. The air cushion is inflated using an air pump, and the inflation pressure can be measured in real time, ensuring a tight fit between the inflated structure and the surface of the hollow cylinder 5 without breaking the inflated structure.

[0059] ② Testing the internal surface resistance of a hollow cylinder, including:

[0060] The third electrode 4 is wrapped around the outer surface A of the hollow cylinder 5;

[0061] Insert the first air cushion 1 into the hollow cylinder 5;

[0062] Inflate the third electrode 4 until it completely covers the outer surface A of the hollow cylinder 5, and use ropes or straps to secure the inflated third electrode 4 to the hollow cylinder 5.

[0063] Inflate the first air cushion 1 until the outer surface of the first air cushion 1 fills the inner surface B of the hollow cylinder 5;

[0064] The inner surface resistance of the hollow cylinder 5 is determined by measuring the first electrode 2, the second electrode 3, and the third electrode 4. This inner surface resistance is determined by the voltage applied between the first electrode 2 and the second electrode 3 and the current between the first electrode 2 and the second electrode 3 on the inner surface of the hollow cylinder 5.

[0065] Furthermore, it should be noted that when measuring the external or internal surface resistance, the dimensions (surface area and volume) of the first air cushion 1 and the internal air cushion of the third electrode 4 can be different, and can be adjusted by those skilled in the art according to the dimensions of the object under test. For example, the area of ​​one side surface (i.e., half the surface area) of the air cushion wrapped around the outer surface of the object under test needs to be greater than the surface area of ​​the outer surface of the object under test, and the area (i.e., surface area) of both sides of the air cushion inserted into the object under test needs to be greater than the surface area of ​​the inner surface of the object under test. Therefore, the dimensions of the air cushion (the first air cushion 1 and the internal air cushion of the third electrode 4) are not considered limiting factors of the present invention.

[0066] In summary, the resistance testing device and method of this invention employs an air-cushion electrode. The first and second electrodes are metal film materials arranged parallel to each other on the air cushion body at a certain distance. The third electrode has a structure with a flexible metal material on the outer surface and an inflatable and deflated inner surface. The metal material on the outer surface of the third electrode can serve as an electrode as a whole. The air cushion body is inflated by an air pump, so that each electrode can be tightly attached to the inner and outer surfaces of the ammunition packaging tube, and the inflation pressure can be measured in real time without breaking the inflatable structure. This enables the surface electrostatic measurement of hollow cylinders such as ammunition packaging tubes.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A resistance testing device, characterized in that, The resistance testing device includes: A first air cushion body (1) that can be inflated and deflated to change its volume; A first electrode (2) and a second electrode (3) are arranged parallel to each other on the outer surface of the first air cushion body (1) at a predetermined interval; and The third electrode (4) has an outer surface that is an electrode, and the third electrode (4) can be filled and released to change its volume.

2. The resistance testing device according to claim 1, characterized in that, The outer surface of the first air cushion (1) is covered with a dielectric film material as a substrate.

3. The resistance testing device according to claim 2, characterized in that, Both the first electrode (2) and the second electrode (3) are metal film materials disposed on the dielectric film material.

4. The resistance testing device according to claim 3, characterized in that, The resistivity of the dielectric film material is higher than 10. 14 Ω; The resistivity of the metal film material is less than 10. 3 Ω.

5. The resistance testing device according to claim 1, characterized in that, The inner liner of the third electrode (4) is an air cushion that can be inflated and deflated to change its volume, and the outer surface of the third electrode (4) is covered with a flexible metal material as an electrode.

6. A resistance testing method, utilizing the resistance testing apparatus as described in any one of claims 1-5, characterized in that, The resistance testing method includes: Test the resistance of the outer or inner surface of a hollow cylinder.

7. The resistance testing method according to claim 6, characterized in that, Testing the surface resistance of a hollow cylinder includes: The first air cushion (1) is wrapped around the outer surface of the hollow cylinder, and the first electrode (2) and the second electrode (3) on the first air cushion (1) are located on the inner side; The third electrode (4) is inserted into the hollow cylinder; Inflate the first air cushion (1) until the first air cushion (1) completely covers the outer surface of the hollow cylinder, and the first electrode (2) and the second electrode (3) are both in contact with the outer surface of the hollow cylinder; The third electrode (4) is inflated until the outer surface of the third electrode (4) fills the inner surface of the hollow cylinder; The outer surface resistance of the hollow cylinder is determined by measuring the first electrode (2), the second electrode (3) and the third electrode (4).

8. The resistance testing method according to claim 6, characterized in that, Testing the internal surface resistance of a hollow cylinder includes: The third electrode (4) is wrapped around the outer surface of the hollow cylinder; Insert the first air cushion (1) into the hollow cylinder; Inflate the third electrode (4) until the third electrode (4) completely covers the outer surface of the hollow cylinder; Inflate the first air cushion (1) until the outer surface of the first air cushion (1) fills the inner surface of the hollow cylinder; The inner surface resistance of the hollow cylinder is determined by measuring the first electrode (2), the second electrode (3), and the third electrode (4).

9. The resistance testing method according to claim 7 or 8, characterized in that, The first electrode (2), the second electrode (3) and the third electrode (4) are all connected by a test line by welding, and the test line is further connected to an electrostatic surface resistance tester.

10. The resistance testing method according to claim 7 or 8, characterized in that, The lengths of the first electrode (2) and the second electrode (3) are fixed, and the distance between the first electrode (2) and the second electrode (3) is fixed.

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