Gas leak detection device and gas leak detection method for detecting gas leaks in test specimens

Abstract

To provide a detection device that enables detection of gas leak locations in test specimens and measurement of total leaks. [Solution] The detection device of the present invention comprises a connector 20 for a test specimen or a test vessel containing the same, a vacuum pump 16, 18 connected to the connector to evacuate the test specimen or test vessel, a gas detector 12 connected to the vacuum pump and connector to detect a first test gas and, while continuing to operate the vacuum pump, perform total leak detection of gas leaks in the test specimen or leak location detection according to the spray principle, a gas pressure sensor 24 connected to the vacuum pump and connector to integrally measure the total pressure increment at the connector according to the pressure increment method and / or measure the partial pressure increment of a second test gas different from the first test gas at the connector according to the partial pressure increment method, and a shut-off device 26 to disconnect the gas pressure sensor and connector from the vacuum pump when inspecting the test specimen using the gas pressure sensor.

Description

[Technical Field]

[0001] The present invention relates to a gas leak detection device for detecting gas leaks in a test specimen, and to a corresponding method. [Background technology]

[0002] Generally, there are two methods for detecting gas leaks: total leak detection and leak location detection. Total leak detection has two options. First, a test specimen pressurized with test gas is placed in a test vessel connected to a gas detector and the test vessel is then evacuated, or the test specimen is placed in a test vessel and pressurized with test gas while the test vessel is evacuated. Second, a test specimen connected to a gas detector is placed in a test vessel or test case, and a test gas, such as ambient air, is supplied to the test vessel or test case before the test specimen is evacuated, or the test specimen is evacuated while the test gas is supplied to the test vessel or test case. Total leak detection only allows for leak detection, not leak location.

[0003] Leak location detection is performed without using a test vessel, using either the sniffing or spraying principle. In the sniffing principle, the test object is pressurized with test gas, and the outside of the test object is sniffed with a sniffing probe connected to a vacuum pump and gas detector. In the spraying principle, the test object is connected to a vacuum pump and gas detector, and the test gas is sprayed from the outside with a spray gun.

[0004] Typically, in gas leak detection systems using helium or hydrogen as the test gas, a mass spectrometer is used as the gas detector, and a high-vacuum pump such as a turbomolecular pump is combined with a vacuum forepump to form the vacuum pump. For leak location detection, the vacuum pump is used to evacuate the test specimen, and the test gas is sprayed from the outside (spray principle). In integrated leak detection, the test specimen is pressurized with the test gas and placed in a test vessel. The test vessel is evacuated by a pre-vacuum pump, and the mass spectrometer measures the test gas content in the vacuum. This test gas content is used as a measure of the leak volume of the test specimen.

[0005] Examples of such vacuum leak detectors include the UL3000 and UL5000 models sold by INFICON®. These systems verify the airtightness of a system by locating the leak by spraying or smelling the test specimen, followed by integral measurement of the pressure increment using a test vessel. To accomplish this, a test specimen placed inside the test vessel connected to the vacuum leak detector is pressurized with a test gas while the test vessel is evacuated. Alternatively, the test specimen connected to the vacuum leak detector is surrounded by the test vessel, pressurized with a test gas, and then evacuated. Alternatively, the test specimen is evacuated while the test vessel is pressurized with the test gas.

[0006] DE 16 48 648 C3 describes a mass spectrometric leak detection system based on the counterflow principle. A test vessel is connected to the inlet of a turbomolecular pump. A test specimen, the leak of which is to be checked, can be placed in the test vessel. The test specimen is filled with a test gas, such as helium. The forepressure side of the turbomolecular pump is connected to a vacuum forepump. An intermediate gas inlet between the turbomolecular pump and the vacuum forepump is connected to the outlet side of another turbomolecular pump, which evacuates a gas detector configured as a mass spectrometer. The two turbomolecular pumps are operated to supply the mass spectrometer with the test gas extracted from the test vessel. The vacuum forepump also evacuates the test vessel and the mass spectrometer.

[0007] EP 1 620 706 B1 describes an arrangement for counterflow leak detection in which a high vacuum pump evacuating a test vessel is connected directly to the inlet of a leak detector, and the test vessel is connected to the inlet without a throttle or any valve, thereby improving the helium suction capacity of the inlet and shortening the response time to the test gas, even when a large volume of test object is connected.

[0008] DE 101 56 206 A and DE 10 2014 223 841 A describe the assembly of a vacuum leak detector with a booster pump, which is an additional turbomolecular pump arranged in the area of ​​the suction port of the vacuum leak detector in order to increase the suction capacity and thus the response time of the vacuum leak detector. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] West German Patent No. 1648648 [Patent Document 2] European Patent No. 1620706 [Patent Document 3] DE 10156206 [Patent Document 4] German Patent Application Publication No. 102014223841 Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved gas leak detection device and corresponding method that allows both gas leak location detection and total leak measurement in a test specimen. [Means for solving the problem]

[0011] A gas leak detection device according to the present invention is defined by the features of claim 1. A method according to the present invention is defined by the features of claim 8.

[0012] In addition to a vacuum pump and a gas detector connected to the vacuum pump, the present invention provides a gas pressure sensor configured as a total pressure sensor (pressure increment method) for integrally measuring the total pressure increment inside the test vessel or test object and / or as a gas-selective partial pressure sensor (partial pressure increment method) for measuring the partial pressure increment of at least one second test gas different from the first test gas inside the test vessel or test vessel. The partial pressure sensor can detect the gas partial pressure, for example, by optical spectrum analysis of the second or further test gas. A shut-off device is also provided, configured to vacuum-isolate the gas pressure sensor and the connector for the test vessel or test object from the vacuum pump when inspecting the test vessel or test object with the gas pressure sensor.

[0013] This allows measurements based on the pressure increment method or accumulation principle to be performed very quickly while the vacuum pump continues to operate. The first test gas is used for the integral measurement or leak location measurement by the gas detector, while at least the second test gas or a further test gas is used for the integral measurement of pressure increments by the gas pressure sensor. Since the shut-off device vacuum-isolates the gas pressure sensor and the test specimen or the test vessel from the vacuum pump during measurement, there is no need to stop or interrupt the operation of the vacuum pump to perform the integral measurement based on the pressure increment method or accumulation principle.

[0014] The vacuum pump may be the only vacuum pump or may be a given vacuum pump in a vacuum pump system consisting of several vacuum pumps, in particular a given high vacuum pump in a vacuum pump system consisting of at least one pre-vacuum pump and at least one high vacuum pump.

[0015] The gas analyzer may be a mass spectrometer equipped with a high vacuum pump, such as a turbomolecular pump, or an ultra-high vacuum pump. The mass spectrometer uses the vacuum pump that evacuates the specimen or the test vessel as a vacuum forepump, and the mass spectrometer is evacuated to the atmosphere by the vacuum forepump. The vacuum forepump and high vacuum pump are sometimes referred to as a vacuum pump system. Alternatively, the gas detector may be an optical gas detector or a semiconductor sensor for a specific gas.

[0016] The gas pressure sensor may be a pressure gauge that measures the total pressure increase inside the test vessel or the test specimen according to a pressure increase method. Alternatively or additionally, the gas pressure sensor may be configured as a gas-selective partial pressure sensor that measures the partial pressure increase of the test gas, where partial pressure refers to the relative content of the test gas in the gas mixture being tested. The partial pressure increase may be measured according to an accumulation method, in which the partial pressure increase of gas accumulated in a measurement region is measured while the vacuum pump is stopped.

[0017] In particular, the gas pressure sensor may be a membrane window type sensor, an absorption spectroscopy type sensor such as an infrared absorption sensor, an emission spectroscopy type sensor such as an optical emission spectroscopy (OES) sensor, a semiconductor type gas sensor, a chemical type gas sensor, or an optical type gas sensor. Specifically, the gas pressure sensor does not necessarily have to be a pressure gauge. In the total pressure increment method, the gas pressure sensor measures the increase in the total pressure of a gas mixture containing the second test gas. In the partial pressure increment method, the gas pressure sensor measures the increase in the partial pressure of at least the second test gas.

[0018] Optical spectrum analysis, represented as an exemplary embodiment of the gas pressure sensor, allows for extremely fast evaluation of total and / or partial pressures according to the pressure increment or accumulation principle. Preferably, the gas-selective partial pressure sensor is an OES sensor configured to perform optical emission spectroscopy.

[0019] Preferably, the pressure sensor is included on or connected to a gas conduit connecting the connector to the test specimen or test vessel to the vacuum pump or gas detector.

[0020] The blocking device may be a selectively controllable blocking device, which blocks by manual and / or electronic and / or pneumatic control. For this purpose, a selectively actuable or controllable valve may be employed on the gas conduit to be blocked. Alternatively, the blocking device may consist of a stop valve, a butterfly valve or a bellows gate valve, which provides vacuum pressure isolation of the gas conduit.

[0021] Preferably, a booster pump evacuates the test space during the measurement so that the gas flowing out of the leak in the test space is compressed in the space downstream of the turbomolecular pump. Since the volume of the test vessel or the test specimen is usually several times larger than the volume of the region downstream of the turbomolecular pump that compresses the gas, the pressure increase in the compressed gas space is approximately equal to the volume ratio.

[0022] Exemplary embodiments of the present invention will now be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary embodiment without a booster pump. [Figure 2] FIG. 2 is a schematic diagram illustrating a corresponding exemplary embodiment with a booster pump. DETAILED DESCRIPTION OF THE INVENTION

[0024] Each figure shows a gas leak detection device with the following components: Gas detector 12; a connector 20 for the test specimen or a test vessel containing the test specimen; and a vacuum pump 16 for evacuating the test object connected to the connector 20 and also the gas detector 12; A gas conducting passage 22 connects the connector 20 to the vacuum pump 16 .

[0025] The gas detector 12 in the illustrated exemplary embodiment is a mass spectrometer evacuated by a turbomolecular pump 18. Here, the gas detector 12 and the turbomolecular pump 18 may be referred to as a detector system. The outlet of the turbomolecular pump 18 is connected to the inlet of the vacuum pump 16, and the inlet of the vacuum pump 16 is used as a vacuum forepump. Thus, the vacuum pump 16 and the turbomolecular pump 18 constitute the vacuum pump 14. The outlet of the vacuum pump 16 opens to the atmosphere.

[0026] In the present invention, a gas pressure sensor 24, configured as, for example, an optical emission spectroscopy (OES) sensor, which may be a total pressure sensor and / or a gas-selective partial pressure sensor, is connected to the gas conduit 22. To this end, a blocking device 26 is provided upstream of the gas pressure sensor 24, i.e., between the gas pressure sensor 24 and the gas conduit 22, thereby connecting the gas pressure sensor 24 to the gas conduit 22. The blocking device 26 is configured to establish a gas-transport connection between the connector 20 and the gas pressure sensor 24 while disconnecting the connections between the connector 20 and other components, particularly the gas detector 12 and the vacuum pump 16. In the simplest case, the blocking device 26 can be a switch that optionally performs one of the following actions: (i) disconnecting the interconnection of the gas conduit 22 between the connector 20 and the vacuum pump 16 and the connection between the gas pressure sensor 24 and the connector 20; or (ii) connecting the gas conduit 22 to the gas pressure sensor 24 and disconnecting the connection between the connector 20 and the vacuum pump 16. The switching device can be a shuttle valve or a 3 / 2-way valve.

[0027] For ease of illustration, the shutoff device 26 is depicted in the drawings as a rectangular region extending across the gas conduits 22, 28 to indicate that the gas conduits 22, 28 can be shut off. This can be achieved by a controllable valve 27 on the gas conduit 22 that shuts off the connection between the connector 20, the gas pressure sensor 24, and the vacuum pump 16. In the illustrated exemplary embodiment, the shutoff device also includes a controllable valve 25 that shuts off the gas conduit 28 that connects the mass spectrometry high vacuum pump 18 (i.e., the high vacuum pump connected to the gas detector 12) to the connector 20 and the gas pressure sensor 24. That is, in the illustrated exemplary embodiment, at least a portion of the shutoff device 26 is included on the gas conduit 22 that shuts off the gas conduit 22.

[0028] Another possible arrangement of gas pressure sensor 24 is shown in dashed lines in Figure 1. That is, gas pressure sensor 24 may be connected to gas conduit 30 connecting vacuum forepump 16 to turbomolecular pump 18. In this case, shut-off device 26 is formed by a controllable valve 29 on gas conduit 30.

[0029] An equivalent arrangement of shut-off device 26 and gas pressure sensor 24 is possible in the exemplary embodiment shown in FIG. 2, but is not depicted in FIG.

[0030] 2, a booster pump 32 configured as a turbomolecular pump is additionally included in the gas conduit 22 for evacuating the connector 20 by the vacuum pump 16. Preferably, the gas pressure sensor 24 and the shutoff device 26 are connected to the gas conduit 22 downstream of the booster pump 32 and upstream of the vacuum pump 16, i.e., to the portion of the gas conduit 22 that connects the booster pump 32 to the vacuum forepump 16. The following describes aspects included in the present invention. [ Aspect 1] A gas leak detection device for detecting a gas leak in a test specimen, a connector (20) for the test specimen or a test vessel containing the test specimen; a vacuum pump (16, 18) connected to the connector (20) for evacuating the test specimen or the test vessel; a gas detector (12) connected to the vacuum pumps (16, 18) and the connector (20) to detect a first test gas, and configured to perform total leak detection of gas leaks in the test object or leak location detection according to a spray principle while continuing to operate the vacuum pumps (16, 18); a gas pressure sensor (24) connected to the vacuum pump (16, 18) and the connector (20) and configured to perform integral measurement of a total pressure increment at the connector (20) according to a pressure increment method and / or to perform measurement of a partial pressure increment of at least one second test gas different from the first test gas at the connector (20) according to a partial pressure increment method; a shutoff device (26) configured to vacuum-isolate the gas pressure sensor (24) and the connector (20) from the vacuum pumps (16, 18) when inspecting the test specimen using the gas pressure sensor (24); and A gas leak detection device comprising: [Aspect 2] The gas leak detection device according to aspect 1, wherein the gas pressure sensor (24) is connected to a gas conduit (22) that connects the connector (20) to the vacuum pump (16, 18) so that the gas pressure sensor (24) measures gas upstream of the vacuum pump (16, 18) and / or connects the connector (20) to the gas detector (12) so that the gas pressure sensor (24) measures gas upstream of the gas detector (12). [Embodiment 3] The gas leak detection device according to embodiment 1, wherein the gas conduit (22) connecting the connector (20) to the vacuum pumps (16, 18) has a booster pump (32), and the gas pressure sensor (24) is provided in the gas conduit (22) upstream of the section between the connector (20) and the booster pump (32), i.e., upstream of the booster pump (32) and the vacuum pumps (16, 18). [Embodiment 4] The gas leak detection device according to embodiment 1, wherein the gas conduit (22) connecting the connector (20) to the vacuum pump (16, 18) has a booster pump (32), and the gas pressure sensor (24) is provided in the gas conduit (22) between the booster pump (32) and the vacuum pump (16, 18), i.e., downstream of the booster pump (32) and upstream of the vacuum pump (16, 18). [Aspect 5] A gas leak detection device according to any one of aspects 1 to 4, wherein the gas pressure sensor (24) is configured to perform optical spectrum analysis of the second test gas. [Embodiment 6] The gas leak detection device according to any one of embodiments 1 to 5, wherein the gas detector (12) is a mass spectrometer equipped with a high vacuum pump (18), particularly an ultra-high vacuum pump, in a gas conduction passage (30) connecting the gas detector (12) to the vacuum pumps (16, 18), and the shutoff device (26) is configured to vacuum-isolate the gas pressure sensor (24) and the connector (20) from the high vacuum pump (18) when the test piece is inspected by the gas pressure sensor (24). [Aspect 7] A gas leak detection device according to any one of aspects 1 to 6, wherein the gas pressure sensor (24) is configured to perform integral measurement of the partial pressure increment of the second test gas at the connector (20) according to the accumulation principle. [Embodiment 8] A gas leak detection method for detecting a gas leak in a test specimen, comprising: supplying a first test gas into the test object or a test vessel surrounding the test object, and detecting the first test gas based on total leak detection or leak location detection according to the spraying principle while continuing to evacuate the test object or the test vessel with a vacuum pump (16, 18); supplying at least one second test gas different from the first test gas to the test object or the test vessel, and detecting a gas leak in the test object by measuring an integral total pressure increment of the test object or the test vessel according to a pressure increment method and / or a partial pressure increment of the second test gas in the test object or the test vessel according to a partial pressure increment method while the test object or the test vessel and the gas pressure sensor (24) are disconnected from the vacuum pump (16, 18), i.e., while the test object or the test vessel is not being evacuated; A gas leak detection method comprising, in any order: [Aspect 9] A gas leak detection method according to aspect 8, wherein the total pressure increment and / or the partial pressure increment of the second test gas are measured in a gas conduit (22) connecting a connector (20) for the test specimen or the test vessel containing the test specimen to the vacuum pump (16, 18) and / or the gas detector (12), or in an expanded or contracted measurement space connected to the gas conduit. [Aspect 10] A gas leak detection method according to aspect 9, wherein the total pressure increment and / or the partial pressure increment are measured in a gas conduit (22) connecting the discharge port of a booster pump (32) whose inlet is connected to the connector (20) for the test specimen or the test vessel with the vacuum pump (16, 18) and / or the gas detector (12), so that the measurement of the total pressure increment and / or the partial pressure increment is performed downstream of the booster pump (32) and upstream of the vacuum pump (16, 18) and / or the gas detector (12). [Aspect 11] A gas leak detection method according to any one of aspects 8 to 10, wherein the partial pressure increment of one or more components in the air is measured. [Aspect 12] A gas leak detection method according to any one of aspects 8 to 11, wherein the partial pressure increment of the test gas is measured by analyzing the optical spectrum of the test gas. [Embodiment 13] A gas leak detection method according to any one of embodiments 8 to 12, wherein the total pressure increment and / or the partial pressure increment of the second test gas are measured in a gas conduit (28) connecting the high vacuum pump (18) of the gas detector (12) to the connector (20) and the gas pressure sensor (24), or in an expanded or contracted measurement space connected to the gas conduit.

Claims

1. A gas leak detection device for detecting a gas leak in a test specimen, a connector (20) for the test specimen or a test vessel containing the test specimen; a vacuum pump (16, 18) connected to the connector (20) for evacuating the test specimen or the test vessel; a gas detector (12) connected to the vacuum pump (16, 18) and the connector (20) to detect a first test gas, and configured to perform total leak detection of gas leaks in the test object or leak location detection according to a spray principle while continuing to operate the vacuum pump (16, 18); a gas pressure sensor (24) connected to the vacuum pump (16, 18) and the connector (20) and configured to perform integral measurement of a total pressure increment at the connector (20) according to a pressure increment method and / or to perform measurement of a partial pressure increment of at least one second test gas different from the first test gas at the connector (20) according to a partial pressure increment method; a shutoff device (26) configured to vacuum-isolate the gas pressure sensor (24) and the connector (20) from the vacuum pump (16, 18) when inspecting the test specimen using the gas pressure sensor (24); a gas conducting passage (22) connecting the connector (20) to the vacuum pump (16, 18) is provided with a booster pump (32); measuring the total pressure increment and / or the partial pressure increment of the second test gas by the gas pressure sensor (24) in the gas detector (12) and / or in the gas conduit (22) provided upstream of the vacuum pump (16, 18) and downstream of the booster pump (32) when the shutoff device (26) is blocked; The gas leak detection device, wherein the gas pressure sensor (24) is disposed in the gas conducting passage (22) between the booster pump (32) and the vacuum pump (16, 18).

2. 2. The gas leak detection device according to claim 1, wherein the gas pressure sensor (24) is connected to a gas conduit (22) that connects the connector (20) to the vacuum pump (16, 18) so that the gas pressure sensor (24) measures gas upstream of the vacuum pump (16, 18) and / or that connects the connector (20) to the gas detector (12) so that the gas pressure sensor (24) measures gas upstream of the gas detector (12).

3. 2. The gas leak detection apparatus of claim 1, wherein the gas pressure sensor (24) is configured to perform optical spectral analysis of the second test gas.

4. 2. The gas leak detection device according to claim 1, wherein the gas detector (12) is a mass spectrometer equipped with a high vacuum pump (18), particularly an ultra-high vacuum pump, in a gas conducting passage (30) connecting the gas detector (12) to the vacuum pumps (16, 18), and the shut-off device (26) is configured to vacuum-isolate the gas pressure sensor (24) and the connector (20) from the high vacuum pump (18) when the test specimen is inspected by the gas pressure sensor (24).

5. 2. The gas leak detection device of claim 1, wherein the gas pressure sensor (24) is configured to perform an integral measurement of the partial pressure increase of the second test gas at the connector (20) according to an accumulation principle.

6. A gas leak detection method for detecting a gas leak in a test specimen, comprising: (A) supplying a first test gas to the test object or a test vessel surrounding the test object, and detecting the first test gas based on total leak detection or leak location detection according to the spray principle while continuing to evacuate the test object or the test vessel with a vacuum pump (16, 18), thereby determining whether the test object has a gas leak; (B) supplying at least one second test gas different from the first test gas to the test object or the test vessel, and detecting a gas leak from the test object by measuring an integral total pressure increment of the test object or the test vessel according to a pressure increment method and / or a partial pressure increment of the second test gas in the test object or the test vessel according to a partial pressure increment method while the test object or the test vessel and the gas pressure sensor (24) are disconnected from the vacuum pump (16, 18), i.e., while the test object or the test vessel is not being evacuated; The total pressure increment and / or the partial pressure increment of the second test gas is measured by the gas pressure sensor (24) in a gas conduit connecting a booster pump (32), the outlet of which is connected to a connector (20) for a test object or test chamber, a vacuum pump (16, 18), and / or a gas detector (12), and the total pressure increment and / or the partial pressure increment are measured downstream of the booster pump (32) and upstream of the vacuum pump (16, 18) and / or upstream of the gas detector (12).

7. A gas leak detection method as described in claim 6, wherein the total pressure increment and / or the partial pressure increment of the second test gas are measured in a gas conduit (22) connecting a connector (20) for the test specimen or the test vessel containing the test specimen to the vacuum pump (16, 18) and / or the gas detector (12), or are measured in an expanded or contracted measurement space connected to the gas conduit.

8. A gas leak detection method as described in claim 6 or 7, wherein the partial pressure increment for one or more components in the air is measured.

9. 9. A method for detecting a gas leak according to any one of claims 6 to 8, wherein the partial pressure increment of the test gas is determined by analyzing the optical spectrum of the test gas.

10. The gas leak detection method according to any one of claims 6 to 9, The gas leak detection method, wherein the total pressure increment and / or the partial pressure increment of the second test gas is measured in a gas conduit (28) connecting a high vacuum pump (18) of the gas detector (12) to the connector (20) and the gas pressure sensor (24), or in an expanded or contracted measurement space connected to the gas conduit.

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