Leak Testing Equipment

Abstract

To provide an improved leak testing device having a membrane that can ensure a stable leak rate. [Solution] A leak testing apparatus (10) having an evacuable test chamber (34) for testing and calibrating the function of a gas leak detection device, the leak testing apparatus (10) comprising a base (12), a cover (16), and at least one side wall (14) connecting the base (12) to the cover (16), the side wall (14) enclosing an internal space (20) that can be filled with a test gas or test fluid, the base (12) having a membrane (24) that is permeable to the test gas, and opposing portions of the inner surfaces (18) of the side walls (14) that face the internal space (20) are positioned at a greater distance from each other in the area of ​​the cover than in the area of ​​the base.

Description

[Technical field]

[0001] The present invention relates to a leak testing apparatus for testing and calibrating the functionality of gas leak detection devices. [Background technology]

[0002] A gas leak detection device usually comprises an evacuable test chamber in which a test object filled with gas or liquid is placed. A gas analyzer is connected to this test chamber, which analyzes the gas drawn from the test chamber and is able to detect whether there is any leaking gas leaking from the test object into the test chamber or whether there is any liquid that has leaked and evaporated due to the leak. It is particularly important here to be able to infer the extent of the leak from the amount of leaking gas detected. For this purpose, a leak test device is used which contains a predetermined amount of a known test gas or test fluid and has a leak of known dimensions and / or a leak with a known degree of leakage relative to the fluid it contains. The leak test device is usually used to test the function of the gas leak detection device and to calibrate the device.

[0003] The leaks in leak test devices are often designed as membranes, and the leak rate depends on the permeability of the membrane to the respective test gas or fluid, the temperature of the membrane, the temperature and vapor pressure of the test gas / fluid, the wetting of the inner / fluid side of the membrane, and the air permeability of the membrane on the outlet side (i.e., outside the leak test device).

[0004] For example, EP 2447694 describes a leak test device filled with a liquid, from which a gas escapes, resulting in the escape of a gas, vapor or liquid component, the gas, vapor or liquid transported by the gas escaping from the leak test device being formed by the liquid according to the vapor pressure characteristic of the membrane or according to the permeability of the solid layer of the membrane.

[0005] The leakage rate in the membrane leakage test depends on whether and to what extent the inside of the membrane is wetted by liquid. In this respect, it is believed that the leakage rate will be greatly affected depending on whether the membrane is in direct contact with the liquid or only liquid vapor is in contact with the membrane. To ensure a stable leakage rate, it is desirable to prevent the liquid from reaching the membrane or to allow only liquid vapor to contact the membrane.

[0006] DE 102014200907 describes a reference gas release device with a reservoir for containing a fluid or a fluid mixture, the reservoir being surrounded by a transport vacuum chamber, in which a chamber pressure of less than 10 kPa is used. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide an improved leak testing device having a membrane capable of ensuring a consistent leak rate. [Means for solving the problem]

[0008] The leak testing device is defined by the features of claim 1 or by the features of claim 2.

[0009] According to them, the leak testing device includes a base, a cover, and at least one sidewall connecting the base and the cover, the base, cover and sidewall enclosing an interior space that can be filled with a test gas or a test liquid. The leak testing device includes a membrane that is permeable to components of the test gas or test liquid, allowing the components of the test gas or test liquid to leak out of the leak testing device through the membrane.

[0010] A feature of the invention is that the membrane is provided at the base of the leak testing device, and the mutually facing portions of the inner surfaces of the side walls facing the internal space are spaced farther apart in the region of the cover than in the region of the base, so that the distance between the opposing portions of the side walls decreases from the cover towards the base, and thus the test fluid contained in the internal space is guided by gravity along the portions of the side walls and directed towards the membrane.

[0011] Alternatively, a recess may be formed in the base of the leak testing fixture, the recess having an inner surface facing the interior space, with opposing portions of the inner surface spaced apart more in the region of the cover than in the region of the base, in other words, the opposing portions of the inner surface spaced apart from each other at a distance that decreases from top (from the cover) to bottom (towards the base).

[0012] The distance between the mutually facing parts of the side wall or the inner surface of the recess facing the interior preferably decreases continuously from the cover towards the base. The inner side may cylindrically surround the interior space and in particular taper conically towards the membrane. Here, in the region of the base, the inner side is advantageously adjacent to the membrane or adjacent to a through-opening formed in the base and containing the membrane.

[0013] In this case, the through-hole and / or the membrane may be cylindrically shaped or may have a circular surface facing the interior, the inner surface of the side wall, or a recess adjacent its outer edge.

[0014] The underside of the base facing outward from the inside, i.e., the outside of the base facing the bottom of the test chamber when the leak test device is placed at the bottom of the test chamber of the gas leak detection device, is advantageously provided with at least one spacer that prevents the underside of the base from contacting the bottom of the test chamber when the leak test device is placed in the test chamber. The spacer facilitates the escape of the test fluid or its vapor from the leak test device into the test chamber through the membrane in the area between the leak test device and the bottom of the test chamber, and allows the test fluid or its vapor to be uniformly distributed in the test chamber.

[0015] The leak testing apparatus preferably includes a fill port that is closed by a valve.

[0016] The present invention provides the advantage that the distance between the opposing sections of the inner surface decreases toward the through opening in the membrane or base, so that gravity moves the test fluid in the leak testing device toward the base (and thus toward the membrane), so that the membrane body is uniformly wetted with the test liquid. The test fluid reservoir volume is the volume enclosed by the base, cover, and side walls of the leak testing device, and tapers from top to bottom, i.e., toward the membrane.

[0017] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view of a leak test device according to a first embodiment. [Diagram 2] FIG. 5 is a cross-sectional view of a leak test device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In either embodiment, the leak testing apparatus 10 includes a base 12 integrally surrounded by a circumferential sidewall 14 that projects laterally from the periphery of the base. A cover 16 is fluid-tightly connected to the sidewall such that the base 12, sidewall 14 and cover 16 fluid-tightly enclose an interior space 20, which can be filled with a test fluid (i.e., a test gas or a test liquid).

[0020] The base 12 is formed with a through opening 22 that connects the internal space 20 with the external environment of the leak test device, and a membrane 24 that is configured to be permeable to the test fluid or its components is inserted into the opening, so that the test fluid contained in the internal space 20 does not leak out of the leak test device unless it passes through the membrane 24.

[0021] The side wall 14 is configured in a ring shape by protruding cylindrically along the outer periphery of the base 12, and its inner surface 26 has a conical shape tapering towards the membrane 24 and the through opening 22. At the lower end of the conical part facing the base 12, the through opening 22 opens, and a central opening is formed adjacent to the membrane 24.

[0022] Because the base 12 and the sidewall 14 are integrally connected to one another, the conical portion of the inner surface 26 may also be considered a recess in the base 12 .

[0023] Due to the effect of gravity and the tapering of the diameter of the internal space 20 towards the through opening 22 and the membrane 24, the test fluid contained in the internal space 20 flows along the inner surface 18 towards the through opening 22 and towards the membrane 24. In this way, the membrane is uniformly wetted by the test fluid as soon as the leak testing device 10 is placed upright on a substrate (e.g., on the bottom 32 of the test chamber 34 of the gas leak detection device, which is not fully shown in the figure).

[0024] In the embodiment of Figure 1, the underside 28 of the base 12 is provided with a number of protruding spacers 30 that protrude downward beyond the underside 28. The spacers 30 create a distance between the underside 28 and the bottom surface of the test chamber when the leak testing apparatus 10 is placed on the bottom surface of the test chamber. In the figure, the bottom of the test chamber is designated by reference numeral 32, and the test chamber is designated by reference numeral 34.

[0025] In one region of the plurality of spacers 30, the base 12 is provided with a filling port 36 that communicates the internal space 20 with the external environment of the leak test apparatus 10, and the filling port is closed with a valve 38. The valve 38 is configured so that the test fluid can be flowed from the outside into the internal space 20 to fill it, but cannot flow out from the internal space 20 to the outside through the filling port 36.

[0026] In the embodiment of FIG. 2, the underside 28 of the base 12 does not have a spacer 30 separate from the underside and is formed so as to be integral with the base, but is formed in the shape of a flat plate and has a shape that concentrically surrounds the through opening 22. In other words, a plurality of spacers 30 are not provided separately from each other so as to be integral with the base. The membrane 24 is inserted into the lower end of the through opening 22. The through opening 22 opens into the internal space 20 in a state of reduced diameter dimensions compared to the membrane 24. The through opening 22 is concentrically surrounded by a plurality of bore holes 40 into which fastening elements in the form of screws for fastening the membrane 24 are inserted, and is held by a conventional screw connection with threaded engagement in the second embodiment. The head of the screw (not shown) inserted from below into the opening 40 with the threaded portion facing upwards protrudes downward beyond the underside 28 of the base 12 and thus forms a spacer similar to the spacer 30 in the first embodiment. The present invention includes the following aspects. [Aspect 1] 1. A leak testing apparatus (10) comprising an evacuable test chamber (34) for placing a test object and / or a leak testing apparatus (10), A leak testing apparatus (10) for testing and calibrating the functioning of a gas leak detection apparatus, The leak test apparatus (10) comprises: A base (12); A cover (16), at least one sidewall (14) connecting the base (12) to the cover (16), the sidewall (14) enclosing an interior space (20) that can be filled with a test gas or fluid; Equipped with The base (12) has a membrane (24) that is permeable to components of the test gas or test fluid; and Opposing portions of the inner surfaces (18) of the side walls (14) facing the interior space (20) are spaced farther apart in the region of the cover than in the region of the base. A leak testing apparatus (10). [Aspect 2] 1. A leak testing apparatus (10) comprising an evacuable test chamber (34) for placing a test object and / or a leak testing apparatus (10), A leak testing apparatus (10) for testing and calibrating the functioning of a gas leak detection device, The leak test apparatus (10) comprises: A base (12); A cover (16), at least one sidewall (14) connecting the base (12) to the cover (16), the sidewall (14) enclosing an interior space (20) that can be filled with a test gas or fluid; Equipped with The base (12) has a membrane (24) that is permeable to components of the test gas or test fluid; and The base has a recess having an inner surface (18) facing the interior space (20); The opposing portions of the inner surface (18) are spaced apart from one another greater in the area of ​​the cover than in the area of ​​the base. A leak testing apparatus (10). [Aspect 3] The leak testing device (10) according to the first or second aspect, A leak testing apparatus (10) characterized in that the distance between opposing portions of the inner surface (18) of the side wall (14) facing the interior space (20) decreases continuously from the cover (16) to the base (12). Aspect 4 4. The leak testing apparatus (10) according to any one of claims 1 to 3, wherein the inner surface (18) of the side wall (14) cylindrically surrounds the interior space (20) and conically tapers towards the membrane. Aspect 5 A leak test device (10) according to any one of aspects 1 to 4, characterized in that in the region of the base, the inner surface of the side wall (14) is adjacent to a through opening (22) constituting the membrane (24). Aspect 6 A leak test apparatus (10) as described in aspect 5, characterized in that the through opening (22) is cylindrically formed, has a circular surface facing inward, and its outer edge is adjacent to the inner surface of the side wall (14). Aspect 7 The leak testing apparatus (10) according to any one of aspects 1 to 6, characterized in that the underside (28) of the base (12) facing away from the internal space (20) is provided with at least one spacer (30) that prevents the underside (28) of the base from contacting a bottom (32) of the test chamber when the leak testing apparatus is placed in the test chamber. Aspect 8 8. The leak testing apparatus (10) according to any one of the first to seventh aspects, characterized in that the leak testing apparatus (10) has a fill port (36) closed by a valve (38). Aspect 9 The leak testing apparatus (10) according to any one of the first to eighth aspects, characterized in that the base (12) and the side wall (14) are formed on an integral member, and the inner surface (18) is formed as a recess in the integral member.

Claims

1. A leak testing apparatus (10) comprising an evacuable test chamber (34) for placing a test object and / or a leak testing apparatus (10), A leak testing apparatus (10) for testing and calibrating the functioning of a gas leak detection apparatus, The leak test device (10) comprises: A base (12); A cover (16); at least one sidewall (14) connecting the base (12) to the cover (16), the sidewall (14) enclosing an interior space (20) that can be filled with a test gas or fluid; Equipped with The base (12) has a membrane (24) that is permeable to components of the test gas or test fluid; and the portions of the inner surfaces of the side walls (14) facing the interior space (20) are spaced farther from each other in the region of the cover than in the region of the base; A leak testing apparatus (10) characterized in that the distance between opposing portions of the inner surface of the side wall (14) facing the interior space (20) decreases continuously from the cover (16) to the base (12).

2. A leak testing apparatus (10) comprising an evacuable test chamber (34) for placing a test object and / or a leak testing apparatus (10), A leak testing apparatus (10) for testing and calibrating the functioning of a gas leak detection device, The leak test device (10) comprises: A base (12); A cover (16); at least one sidewall (14) connecting the base (12) to the cover (16), the sidewall (14) enclosing an interior space (20) that can be filled with a test gas or fluid; Equipped with The base (12) has a membrane (24) that is permeable to components of the test gas or test fluid; and The base has a recess on an inner surface facing the internal space (20), the opposing portions of the inner surfaces are spaced apart more at an end facing the cover (16) than at an end facing away from the cover (16); A leak testing device (10) characterized in that the distance between opposing portions of the inner surface facing the interior space (20) decreases continuously from the end facing the cover (16) to the end remote from the cover (16).

3. 3. The leak testing device (10) of claim 1 or 2, characterized in that the inner surface of the side wall (14) cylindrically surrounds the internal space (20) and conically tapers toward the membrane.

4. A device (10) for leak testing as described in any one of claims 1 to 3, characterized in that in the region of the base, the inner surface of the side wall (14) is adjacent to a through opening (22) constituting the membrane (24).

5. 5. A leak testing apparatus (10) according to claim 4, comprising: The through opening (22) is cylindrically shaped, has an inwardly facing circular surface, and its outer edge is adjacent to the inner surface of the side wall (14).

6. A leak testing device (10) according to any one of claims 1 to 5, comprising: The leak testing apparatus (10) is characterized in that the underside (28) of the base (12) facing away from the internal space (20) is provided with at least one spacer (30) that prevents the underside (28) of the base from contacting the bottom (32) of the test chamber when the leak testing apparatus is inserted into the test chamber.

7. 7. The leak testing apparatus (10) according to any one of claims 1 to 6, characterized in that the leak testing apparatus has a filling port (36) closed by a valve (38).

8. A leak testing device (10) according to any one of claims 1 to 7, comprising: A leak testing apparatus (10) characterized in that said base (12) and said side wall (14) are formed on an integral member, and said inner surface is formed as a recess in said integral member.

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