ASU helium detection test system

Abstract

The invention discloses an ASU helium detection test system, and relates to the field of automobile part sealing detection, and the system comprises a gas source supply unit which is used for providing at least two test gases with different properties; the gas circuit construction unit comprises a controlled multi-way valve group and is used for performing selective fluid connection on the gas source supply unit, the to-be-detected module, the pumping and draining unit and the detection unit; the pumping and discharging unit is used for carrying out vacuumizing treatment on the test gas path before the test and recovering the test gas after the test; the detection unit is used for collecting physical state parameters and leakage medium concentration parameters of the to-be-tested module in the testing process; and the control unit is configured to execute a sealing performance detection process comprising at least two different test stages. According to the scheme, large leakage pre-screening can be carried out by utilizing a low-cost medium so as to protect a helium detector and reduce medium consumption, and closed-loop gas recovery circulation is constructed so as to remarkably reduce the use cost of high-value tracer gas.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile component sealing detection, in particular to an ASU helium detection test system. BACKGROUND

[0002] The automobile suspension air supply module is a core component of the air suspension system, and its sealing performance is directly related to the response speed, holding capacity and vehicle safety of the suspension system. The industry has high requirements for the sealing detection of such precise pneumatic components, especially the reliable identification of micron-level leakage. The helium mass spectrometry leak detection technology has become the recognized preferred solution in the field of high-precision sealing test, especially micro-leak detection, due to its high detection sensitivity and stability for helium molecules. This technology usually fills helium into the tested workpiece and uses a helium mass spectrometer to detect the concentration of tracer gas in the periphery or downstream to quantitatively evaluate the leakage rate. To achieve comprehensive detection of the complex internal valve path and overall housing of the ASU, an automated test system capable of realizing multi-gas path switching, accurate parameter collection and analysis needs to be built.

[0003] However, the traditional direct helium detection method has significant limitations in actual industrial application. First, for defective products with large leaks, direct injection of high-cost helium will cause a large amount of gas to escape, not only wasting expensive test media, but also potentially damaging the precise helium mass spectrometer due to the instantaneous high-pressure impact. Second, the helium recovery process introduced to protect equipment and reduce costs often affects the stability of the environmental background for subsequent tests due to incomplete recovery of residual gas in the test cavity, leading to measurement data drift or poor repeatability. If direct discharge is chosen, the test cost will rise sharply. Third, the control logic of existing test systems is mostly fixed and single, making it difficult to adapt to the testing needs of different valve path combinations within the ASU, and lacking the ability to perform in-depth analysis and positioning diagnosis of test data. There is room for optimization in terms of test efficiency, cost control and intelligence. Therefore, based on the above problems, the present application proposes an ASU helium detection test system. SUMMARY

[0004] To solve the above problems, the purpose of the present application is to provide an ASU helium detection test system that uses low-cost media for large-leakage pre-screening to protect the helium detector and reduce media consumption, builds a closed-loop gas recovery cycle to significantly reduce the cost of using high-value tracer gas, and adopts a programmable modular control strategy to achieve comprehensive testing and leakage positioning for complex internal valve path structures in the ASU.

[0005] To achieve the above object, the present application provides an ASU helium detection test system, which first uses nitrogen to pre-screen the ASU to be tested for large leakage, quickly eliminates serious defective products and protects subsequent precision instruments; then, the test pipeline is completely evacuated; subsequently, it is switched to use helium for high-sensitivity micro-leakage precision detection. During the whole process, through the cooperative control of the multi-way valve group, the automatic switching of the test, vacuumization and gas recovery gas paths is realized. At the same time, the system integrates a helium recovery and purification circulating device to recover and purify the tested helium for reuse. The control unit adopts modular programming, allowing users to flexibly configure test logic according to product internal valve paths, and realizing quantitative evaluation and position judgment of leakage based on multi-sensor data fusion analysis.

[0006] In a first aspect, the present application provides an ASU helium detection test system, comprising: a gas source supply unit for providing at least two different test gases; a gas path construction unit comprising a controlled multi-way valve group for selectively fluidly connecting the gas source supply unit, the module to be tested, the evacuation unit and the detection unit to form different test gas paths; an evacuation unit for vacuumizing the test gas path before testing and recovering the test gas after testing; a detection unit for collecting physical state parameters and leakage medium concentration parameters of the module to be tested during testing; a control unit in communication connection with the gas path construction unit, the evacuation unit and the detection unit, configured to execute a sealing detection process comprising at least two different test stages.

[0007] Further, the sealing detection process comprises: in the first test stage, the gas path construction unit is controlled to form a first test gas path, and the module to be tested is pre-tested for large leakage by using the first test gas from the gas source supply unit; after the first test stage, the evacuation unit is controlled to remove the first test gas residue in the test gas path; in the second test stage, the gas path construction unit is controlled to form a second test gas path, and the module to be tested is precisely tested for micro-leakage by using the second test gas from the gas source supply unit, the detection sensitivity of the second test gas being higher than that of the first test gas; the control unit further calculates and outputs the sealing determination result of the module to be tested according to the data collected by the detection unit.

[0008] Further, the large leakage pre-detection in the first test stage specifically comprises: The first test gas is filled into the to-be-tested module and pressure is maintained, and the pressure change downstream of the to-be-tested module is monitored by the detection unit; if the pressure change exceeds a first preset threshold, it is determined that there is a large leakage and the entire test process is terminated.

[0009] Further, the gas source supply unit includes a high-pressure helium gas source and a high-pressure nitrogen gas source, the first test gas is nitrogen, and the second test gas is helium.

[0010] Further, the control strategy of the multi-way valve group is configured to enable independent or combined sealing tests for different test cavities or fluid channels inside the to-be-tested module, and to realize positioning of a leakage point by analyzing the parameter changes of the detection unit under different test gas circuits, thereby improving the diagnostic capability of the test.

[0011] Further, the purging operation performed by the pumping and exhausting unit between the first test stage and the second test stage includes the steps of first vacuumizing the test pipeline and the interior of the to-be-tested module, then introducing inert gas for purging, and then vacuumizing again, so as to ensure that the first test gas residue is sufficiently removed, thereby ensuring the reference stability of the micro-leakage precision test result.

[0012] Further, the control unit is configured as a programmable modular control architecture, in which basic test logic corresponding to various valve circuit structures inside the to-be-tested module is pre-set, and users are allowed to customize combinations, edit test parameters and determination thresholds on this basis, so as to flexibly adapt to the test requirements of different specifications of products, and support storage, calling and exporting of test programs and data.

[0013] Further, the system further includes a gas recycling unit; an inlet end of the gas recycling unit is connected to the gas circuit construction unit, for receiving and processing the second test gas from the test gas circuit; the gas recycling unit further includes a purification module and a pressurization module, for purifying and pressurizing the recycled gas, and then sending it back to the gas source supply unit or directly supplying it to the second test stage for recycling, thereby realizing recycling of the test gas, and significantly reducing test medium consumption and operating costs.

[0014] Further, the gas recycling unit further includes a concentration monitoring module; the control unit dynamically adjusts the recovery parameters of the pumping and exhausting unit or the gas recycling unit according to the recovery gas concentration information fed back by the concentration monitoring module, so as to realize optimized control of the recovery process and closed-loop management of the purity of the recycled gas.

[0015] The second aspect also provides an ASU helium detection test method, including: controlling the pumping and exhausting unit to vacuumize the test gas circuit including the to-be-tested module; controlling the gas path construction unit to connect the first test gas source and the to-be-tested module, and performing large-leakage pre-detection; If the large-leakage pre-detection passes, the evacuation unit is controlled again to evacuate the test gas path, so as to remove the first test gas residue; Before the second test gas is introduced, the background value detected by the detection unit is recorded; The gas path construction unit is controlled to connect the second test gas source and the to-be-tested module, and micro-leakage fine detection is performed, and the detection value is recorded; The second test gas detection value recorded in the micro-leakage fine detection step is compared with the background value recorded in the background recording step, the actual leakage value of the to-be-tested module is calculated, and the sealing property is determined according to the actual leakage value.

[0016] Further, after the micro-leakage fine detection step, a gas recovery step is further included: The gas path construction unit is controlled to act in cooperation with the evacuation unit or the gas recovery circulation unit, so as to recover the second test gas remaining in the test gas path.

[0017] Further, the method realizes the respective test and evaluation of the multiple internal valve positions and the overall external leakage of the to-be-tested module by sequentially switching different valve path states in the to-be-tested module and repeating the initial preparation step to the result calculation step.

[0018] The present application provides an ASU helium detection test system, which first uses a low-cost inert gas to perform large-leakage pre-screening on a to-be-tested module, so as to quickly identify and isolate products with serious defects; then, the test pipeline is thoroughly evacuated and purged to remove the residual test medium; finally, a high-sensitivity tracer gas is switched to for precise micro-leakage detection. In order to realize this process, the system integrates a multiple controlled valve group to construct a flexible gas path, a closed-loop gas recovery purification unit to realize the recycling of test gas, and a control unit supporting modular programming. The control unit can adaptively configure test logic and control sequences according to the complex valve path structure inside the ASU, cooperatively schedule actions such as gas path switching, evacuation, inflation, detection and recovery, so as to realize the test and leakage positioning of the overall external leakage and the sealing property of multiple independent valve positions inside the module.

[0019] This system offers several beneficial effects. First, the large leak pre-screening stage effectively avoids the ineffective consumption of high-value tracer gases and eliminates the potential damage to high-sensitivity detection instruments caused by instantaneous pressure surges from large leaks, thus improving system reliability and lifespan. Second, the closed-loop gas recovery and recycling mechanism significantly reduces the long-term operating costs of the test media. Third, multi-stage testing combined with a precise residue removal process ensures the stability of the environmental background during the micro-leak detection stage, thereby guaranteeing high accuracy and repeatability of test results. Fourth, the modular and programmable control architecture gives the system strong flexibility and adaptability, enabling rapid response to changes in different product models and testing requirements, achieving standardization and intelligentization of the testing process, and significantly improving testing efficiency and diagnostic capabilities.

[0020] Beneficial effects By implementing the ASU helium detection system provided by the present invention, the following technical effects are achieved: (1) By adding a rapid large-leakage pre-screening process using low-cost media before performing high-sensitivity tracer gas detection, a two-stage filtering test process was constructed. This avoids the waste of high-value detection media caused by large leaks in defective products from the source of the test logic, and fundamentally eliminates the risk of pressure shock to downstream precision testing instruments under large-leakage conditions. Thus, while ensuring test accuracy, it significantly improves the economy and operational reliability of the entire test system.

[0021] (2) The integrated purification and pressurization gas recovery and circulation path can actively recover, purify and repressurize the high-value tracer gas remaining in the tooling and products after the test is completed for reuse. It transforms the test medium, which is a consumable in traditional open-loop testing, into a recyclable resource. By significantly reducing the net consumption of the medium per test, it achieves a revolutionary reduction in testing costs and provides a sustainable material supply guarantee for continuous production.

[0022] (3) A highly flexible gas path network was constructed using a controlled multi-way valve group, and corresponding control strategies were configured. This allows a single test system to quickly reconstruct the gas path connection through software commands, thereby seamlessly adapting to the independent or combined sealing test requirements of different cavities and valve positions within the module under test. This not only enables one-stop comprehensive testing of complex products, but also allows for preliminary location of leaks by analyzing the differences in response data under different test paths, enhancing the diagnostic capabilities of the test.

[0023] (4) The control core of the test system is designed with a modular and programmable software architecture. This gives the system strong flexibility and adaptability. Users can freely define and combine test steps, parameters, and criteria according to the internal valve layout of specific products through graphical or script-based methods, thereby decoupling the universality of the hardware system from the specialization of specific test processes. This enables the same hardware platform to quickly respond to changes in different products or test standards, greatly shortening the process debugging cycle and promoting the standardization of test processes and knowledge accumulation. Attached Figure Description

[0024] To make the above-described ASU helium detection system of the present invention more apparent and understandable, the accompanying drawings used in the specific embodiments of the present invention 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 from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the method flow of this application; Figure 2 This is a schematic diagram illustrating the system principle of this application; Figure 3 This represents the test vacuum circuit diagram; Figure 4 This diagram illustrates the principle of a helium detection test product. Figure 5 This shows the test gas circuit diagram for SV1 and 2 helium detection. Figure 6 This shows the test gas circuit diagram for SV3 and 4 helium detection.

[0026] Explanation of reference numerals in the attached figures: QV01~QV21 are pneumatically controlled solenoid valves used to control the opening and closing of gas paths for testing, vacuuming, and recovery; T1~T6 and H1~H6 are temperature and humidity sensors used to monitor the testing environment; P1~P6 are equipment-side pressure sensors used to monitor pressure changes at each test node; I-U1~I-U4 are grating rulers; I-M1~I-M4 are regulating motors; ID1 is the equipment dryer used to ensure the test gas is dry; A1 and A2 are pressure gauges; V1 and V2 are one-way valves; AS1 and AS2 are current sensors used to monitor the current of the compressor motor or valve group; FL, FR, RL, and RR are the left front wheel cylinder, right front wheel cylinder, left rear wheel cylinder, and right rear wheel cylinder, respectively; AD is the product dryer; EV is the exhaust valve; P / U represents the internal temperature / pressure sensor used to monitor the internal state of the product; CM is the compressor motor. Motor); SV1~SV4 are switching valves; AV1~AV4 are air valves, which are connected to the four wheel ends respectively. Detailed Implementation

[0027] Example 1: This embodiment illustrates a specific working method of an ASU helium detection system. The method flow is as follows: Figure 1 As shown, its core lies in the adoption of a two-stage differentiated testing strategy, which is implemented through a programmable multi-way valve group system.

[0028] The system principle is as follows: Figure 2 As shown, after the system starts working, it first enters the initialization and vacuuming phase. At this time, the control unit drives specific valves in the gas path construction unit to operate according to a preset program. Specifically, as... Figure 3 As shown, the control unit instructs valves QV3, QV6, and QV7 to open, while ensuring that valves QV5 and QV10 are closed. This valve combination constitutes the vacuum path from the ASU product under test through the recovery pipeline to the vacuum pump. After the vacuum pump is started, the system performs a vacuum operation on the connected test pipeline and the internal cavity of the ASU to remove air and create a clean, low-background initial environment for subsequent testing, ensuring test accuracy. Once the pressure sensor in the system detects that the vacuum level has reached the preset threshold, the large leakage pre-screening is initiated.

[0029] The pre-screening stage for major leaks aims to quickly and cost-effectively identify and reject defective products with severe leaks. At this stage, the control unit switches the gas path: valves QV3 and QV5 are closed, while valve QV4 is opened. This connects the high-pressure nitrogen source to the test inlet of the ASU under test, while the ASU's outlet is kept closed by valves QV8 and QV9, forming a sealed test chamber. The system fills the ASU with nitrogen at a certain pressure and maintains that pressure. During this period, a high-precision pressure sensor continuously monitors pressure changes downstream of the ASU or within the sealed chamber. The algorithm within the control unit analyzes the pressure decay curve in real time. If the pressure drop rate exceeds the first threshold set for major leaks, the product is immediately deemed unqualified, the entire testing process is terminated, and the product is rejected. This stage uses inexpensive nitrogen instead of expensive helium for the initial screening, which not only significantly reduces the waste of test media caused by major leaks but, more importantly, completely avoids the instantaneous high-pressure gas flow from major leaks directly impacting the precision helium mass spectrometer leak detector at the back end, effectively protecting the core testing equipment and improving the system's reliability and lifespan.

[0030] If the product successfully passes the large leak pre-screening, it enters the transitional purification stage. To ensure the absolute accuracy of subsequent helium detection, residual nitrogen gas remaining in the test pipeline and ASU must be thoroughly removed. The control unit switches the gas path again: QV3 is activated, QV5 is deactivated, and possibly QV6 and QV7 are activated in combination to reconstruct the vacuum path. The system performs a second vacuum, and if necessary, inert gas can be introduced for purging before vacuuming again to ensure that nitrogen residue is reduced to an extremely low level. This step is the core link to ensure the stability of the micro-leak detection background. After purification, the system performs a background recording operation: valve QV9 is opened to connect the helium mass spectrometer leak detector to the test pipeline, and the current ambient helium background reading is recorded without helium being introduced. This value will be used as the benchmark for subsequent calculations.

[0031] Following this, the second stage of micro-leakage detection begins. This involves using helium as a tracer gas for highly sensitive detection. The control unit shuts off QV3 and QV5, opens QV1, connects the high-pressure helium source to the ASU inlet, and simultaneously keeps QV8 and QV9 open, enabling the helium mass spectrometer to detect any potential helium leaks. Figure 4 As shown, helium is filled into the ASU. The helium mass spectrometer leak detector begins high-sensitivity monitoring. After the test, the control unit performs differential calculations between the collected peak or cumulative helium concentration signal and the previously recorded environmental background value to obtain the net leakage value. This value is then compared with the preset micro-leakage acceptance threshold to ultimately determine whether the product's sealing performance meets the standard. For complex components like the ASU with multiple internal solenoid valves, this system can preset different valve control sequences through software to cyclically execute the above process, achieving comprehensive testing of each valve position and the entire housing, demonstrating its high flexibility and completeness.

[0032] Example 2: Building upon the aforementioned embodiments, this paper focuses on the physical entity of the test system and details how it achieves cost control through an integrated closed-loop helium recovery cycle subsystem.

[0033] This system is not simply a combination of gas paths, but a sophisticated mechatronic platform managed collaboratively by an intelligent control unit. The core hardware comprises several key units: a gas supply unit, including at least high-pressure helium and nitrogen cylinders, providing precise micro-leak detection and cost-effective large-leak pre-screening media respectively; a gas path construction unit, consisting of dozens to hundreds of precision solenoid valves, pipelines, filters, and pressure regulating valves numbered QV1, QV3, QV4, etc., controlled by a central controller, capable of precise switching like railway switches to form various testing, vacuuming, and recovery gas paths; an extraction unit, mainly composed of vacuum pumps and exhaust valves, responsible for providing a vacuum environment and performing initial gas extraction for recovery; and a detection unit, integrating pressure sensors, flow meters, and, most importantly, a helium mass spectrometer leak detector, responsible for data acquisition throughout the entire process.

[0034] In addition, an independently designed and integrated gas recovery and circulation unit forms a complete closed-loop subsystem. After the helium testing step of any ASU product is completed, regardless of whether the product passes or fails, a helium mixture remains in the system. At this point, the control unit initiates the recovery procedure: it instructs the gas path construction unit to switch to recovery mode, specifically by opening valves QV20, QV19, QV12, and V16, and closing QV18 and QV21. This valve combination connects the test fixture, product chamber, and piping to the recovery loop. A vacuum pump starts, drawing the residual helium mixture into a low-pressure buffer tank. Subsequently, a booster pump in the recovery loop operates, pressurizing the gas and sending it to a purification module. This module efficiently separates and purifies the helium from impurities such as air and nitrogen. The purified high-pressure helium is stored in a dedicated high-pressure tank for use in the next test cycle. To intelligently manage this process, a helium concentration sensor is also installed in the subsystem. Its feedback signal forms a closed-loop control: the control unit monitors the purity of the recovered gas in real time and dynamically adjusts parameters such as recovery time and vacuum pump power to ensure recovery efficiency and gas quality. Calculations show that the system achieves a helium recovery efficiency of over 90%. Combined with a pre-screening strategy to filter out defective products with severe leaks, it avoids the complete waste of helium caused by directly using helium on such products, significantly reducing the overall helium consumption of the system. Based on an 8-hour production line operation and a 90-second testing cycle, the traditional direct helium detection method requires approximately 320 tests per day, with each test consuming about 0.05 liters of helium, resulting in a total daily loss of about 16 liters. If a product with a large leak is encountered, the instantaneous discharge can further increase the loss to around 20 liters. This system, however, eliminates defective products through pre-screening for large leaks and recovers and purifies the helium after testing qualified products, achieving a gas recycling rate of over 90%. After comprehensive calculation, the system can reduce the daily net loss of helium to about 3 liters, achieving a significant reduction in testing costs and making high-precision helium detection technology economically feasible for large-scale industrial production.

[0035] Example 3: Building upon the aforementioned embodiments, this paper elaborates on the modular programmable control unit and its complex testing logic, particularly how to utilize... Figure 5 , Figure 6 The different test gas path configurations shown enable precise testing and leak location for specific valve groups within the ASU.

[0036] The control unit consists of an industrial computer or a high-performance programmable logic controller equipped with dedicated software. It deeply couples the physical connection of the hardware pneumatic circuit with the logical control of the software, realizing a leap from overall testing to targeted diagnosis.

[0037] like Figure 5 and Figure 6As shown, although the internal piping structure of the ASU product is fixed, distinctly different test isolation chambers can be constructed by controlling the opening and closing states of the product's internal solenoid valves and simultaneously switching the gas path of the external test fixture. For example, when testing the sealing performance of valves SV1 and SV2, the control unit sends a command to the ASU product, placing its internal valves SV1 and SV2 in the specific state under test, and potentially connecting SV3 and SV4. In conjunction with this, the gas path construction unit of the external fixture is controlled to form a dedicated pathway, precisely guiding the test helium to the chamber inlet associated with valves SV1 and SV2, while simultaneously connecting the detection circuit to the corresponding outlet. Figure 5 What is shown is the static fluid connection relationship of the entire system at this moment. Similarly, when it is necessary to test valves SV3 and SV4, the control unit will change the command, switch the state of the internal valves of the ASU, and synchronously drive the external valve group to switch to another predetermined configuration, thereby forming... Figure 6 The new air path shown.

[0038] Based on this, the system can perform systemic leak location analysis. When the overall product sealing test fails, the control unit can automatically activate the diagnostic mode. It will sequentially execute preset test steps for different internal valve assemblies. Since each test only focuses on a portion of the sealing interface, the leak signals detected by the helium mass spectrometer in different test steps will show significant differences. The control unit's data processing algorithm will analyze this difference in real time: if a high leak signal is detected only when executing test steps SV1 and 2, while the signal is weak in test steps SV3, 4, and other test steps, the leak source can be located with high confidence in the sealing link related to valve SV1 or SV2. This process elevates the previously vague judgment of leaks to a precise diagnosis of where the leak is, greatly improving maintenance efficiency and the targeted nature of process improvements.

[0039] In summary, by automatically and cyclically calling up the gas path configuration through the control unit, the system achieves refined sealing detection and diagnosis of complex components such as the ASU.

Claims

1. An ASU helium detection system, characterized in that, include: A gas supply unit is used to provide at least two test gases with different properties; The gas path construction unit includes a controlled multi-way valve group for selectively fluidly connecting the gas source supply unit, the module under test, the extraction unit and the detection unit to form different test gas paths. The vacuum unit is used to evacuate the test gas path before testing and to recover the test gas after testing. The detection unit is used to collect the physical state parameters and leakage medium concentration parameters of the module under test during the test. The control unit, which is communicatively connected to the gas path construction unit, the extraction unit, and the detection unit, is configured to perform a sealing test process that includes at least two different test phases.

2. The system according to claim 1, characterized in that, The sealing performance testing process includes: In the first testing phase, the gas path construction unit is controlled to form a first test gas path, and the first test gas from the gas source supply unit is used to perform a large leakage pre-detection on the module under test. After the first test phase is passed, the extraction unit is controlled to remove the first test gas residue in the test gas path; In the second testing phase, the gas path construction unit is controlled to form a second test gas path, and the second test gas from the gas source supply unit is used to perform micro-leakage detection on the module under test. The detection sensitivity of the second test gas is higher than that of the first test gas. The control unit also calculates and outputs the sealing performance determination result of the module under test based on the data collected by the detection unit.

3. The system according to claim 2, characterized in that, The first phase of large leakage pre-detection specifically includes: The test module is filled with a first test gas and pressurized. The pressure change downstream of the test module is monitored by the detection unit. If the pressure change exceeds a first preset threshold, it is determined to be a major leak and the entire test process is terminated.

4. The system according to claim 2, characterized in that: The gas supply unit includes a high-pressure helium source and a high-pressure nitrogen source, wherein the first test gas is nitrogen and the second test gas is helium.

5. The system according to claim 1, characterized in that: The control strategy of the multi-way valve group is configured to perform independent or combined sealing tests on different test chambers or fluid channels inside the module under test, and to locate the leak point by analyzing the changes in the parameters of the detection unit under different test gas paths.

6. The system according to claim 1, characterized in that: The system also includes a gas recovery and circulation unit; the inlet of the gas recovery and circulation unit is connected to the gas path construction unit, and is used to receive and process the second test gas from the test gas path; the gas recovery and circulation unit also includes a purification module and a pressurization module, which are used to purify and pressurize the recovered gas and then send it back to the gas source supply unit or directly supply it for recycling in the second test stage.

7. The system according to claim 6, characterized in that: The gas recovery and circulation unit also includes a concentration monitoring module; the control unit dynamically adjusts the recovery parameters of the extraction unit or the gas recovery and circulation unit based on the recovered gas concentration information fed back by the concentration monitoring module.

8. An ASU helium detection method, characterized in that: The method is implemented based on the system described in any one of claims 1-7: The method includes: The pumping unit is controlled to evacuate the test gas path, which includes the module under test. The gas path construction unit is controlled to connect the first test gas source and the module under test to perform a large leak pre-detection. If the large leak pre-detection passes, the pumping unit is controlled again to evacuate the test gas path to remove the first test gas residue. Before introducing the second test gas, record the environmental background value detected by the detection unit; The gas path construction unit is controlled to connect the second test gas source and the module under test, perform micro-leakage fine detection, and record the detection value; The detection value of the second test gas recorded in the micro-leakage fine measurement step is compared with the environmental background value recorded in the background recording step to calculate the actual leakage value of the module under test, and the sealing performance is determined accordingly.

9. The method according to claim 8, characterized in that, Following the microleakage detection step, a gas recovery step is also included: The gas path construction unit is controlled to work in coordination with the extraction unit or the gas recovery and circulation unit to recover the second test gas remaining in the test gas path.

10. The method according to claim 8, characterized in that: The method achieves separate testing and evaluation of multiple internal valve positions and overall external leakage of the module under test by sequentially switching different valve states inside the module under test and repeating the initial preparation steps to the result calculation steps.

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