Quick Q&A: What Does an Air Tightness Tester Do? A Detailed Explanation of Its Working Principle and Industry Applications

Q1:Airtightness TesterWhat exactly do we do?

Turn a product’s “invisible leaks” into data that can be measured, analyzed, and traced.

Many products appear to fit together perfectly on the outside, but may harbor internal defects invisible to the naked eye—such as tiny cracks, porosity in welds, improperly installed seals, and failed housing seams.Airtightness Tester(It is also commonly referred to in the industry asairtightness meter,leak detector,differential pressure meter,flow metermaybeMoisture Analyzer)Its function is to convert these hidden defects into data that equipment can quantify and evaluate through measures such as pressure, differential pressure, and flow rate.

Different industries have their own terms for this type of equipment: in the consumer electronics and home appliance sectors, it is commonly referred to asWaterproof TestermaybeWaterproof testing equipment...used to verify waterproof ratings such as IP67, IP68, and IP69; more commonly used in the medical device, automotive, and packaging industriesSealing Tester; whereas in industrial applications such as new energy batteries, water pumps, and valves,leak detector,Leak Detectormaybeleak detector...is the more common term. Regardless of how the name may change—Air tightness tester,Air tightness testing equipment,Sealing TesterOrLeak Detection Equipment—The underlying logic has always been the same:Identify Leaks with Data, Safeguard Quality with PrecisionThe

Q2: Why do products need to undergo airtightness testing?

Because "working" does not mean "working reliably over the long term."

Different industries express their concerns in different ways, but they all point to the same thing:

sector	Key Concerns
Cell Phones, Smart Wearables	Water and Dust Resistance
New Energy Battery	Housing Sealing and Long-Term Reliability
Auto Parts	Does the sealing performance meet the operating conditions?
Medical Equipment	Seal Consistency and Batch Stability

All of these needs point to the same issue:Does the product's sealing performance actually meet the requirements?

Q3: How does a leak tester determine whether there is a leak?

Apply pressure to the product and observe changes in pressure or flow rate.

Taking the most common direct-pressure method as an example, the process is as follows:Inflate → Balance → Check → EvaluateTheWhen there are no leaks in the product, the pressure changes very little during the pressure-holding phase..;When a leak occurs, the pressure drops according to a certain pattern.. The device detects this change, compares it to a preset threshold, and ultimately outputs PASS / NG Results.

Q4: What are the different methods for leak testing, and how do you choose among them?

Each of the four mainstream principles has its own applicable scenarios, as shown in the figure above.differential pressureDue to its strong resistance to interference and high repeatability, it is most widely used in automotive components and new energy structural parts—Jingcheng Engineering’s JC-C10005 rangeThis is a representative product of this technological approach. The differential pressure method focuses on "Pressure difference between the two sides", the Traffic Law focuses on "How much air has leaked out?", and the two address sealing issues in different dimensions.

Q5:Airtightness Testercap (a poem)Water tightness testerIs it the same thing?

Not entirely, but the two can complement each other.

Airtightness TesterUse compressed air to detect leaks based on pressure, differential pressure, flow rate, and other factors;Watertightness Testing EquipmentWaterproofing is then verified through methods such as water pressure testing, immersion, and spray testing. In actual production, these two methods are often used in combination—First, useairtightness meterConduct 100% inspection during mass production to screen out the vast majority of defective units, and then perform sampling-based waterproof testing in accordance with product protection rating standards.The

Q6:Airtightness TesterIs it only suitable for products that “have an interface”?

No.

There are test interfacesThe products useDirect-Pressure or Differential-PressureInspection: For a fully sealed structure with no inflation ports, the following method can be used:Volume-based dosing and other approachesThe

JC-LZ10020 Volumetric Quantitative Airtightness Tester

The most important step before selecting equipment is to determine:Is the product a perforated structure or a fully enclosed structure? This determines the testing protocol, not the equipment brand.

Q7: Can a single device test multiple models?

Yes, the key is switching the tooling and fixtures, not the equipment.

Air Tightness Solutions for Multiple Product Models

For multiple models from the same manufacturer, if they share the same detection principle, it is entirely possible to useOne equipment platform + multiple sets of custom tooling and fixturesThis approach allows for the production of different products through quick changeovers. This is precisely the approach commonly taken by JCGK:Shared equipment platforms; fixtures are customized based on product design... to reduce duplicate purchases while improving equipment utilization.

Q8: QiTightness TesterWhat else can it do besides determining "OK" or "NG"?

Data collection and traceability are becoming more valuable than the determination itself.

Previous tests could only answer “Is this one okay?". Jingcheng Engineering'sAir tightness testing equipmentDepending on the configuration, the system can perform functions such as recording test pressures and leak values, linking barcodes, querying historical data, and integrating with the MES system.

The answer is now:When was the test conducted? What was the test pressure? What was the leak rate? Which production line manufactured the product? For the new energy, automotive, medical, and liquid cooling industries, this data chain serves as the core foundation of their quality systems.

Q9:Airtightness TesterCan it be integrated into an automated production line?

Yes, and this is becoming the mainstream approach.

The complete automated inspection station consists of:Robotic Loading → Automatic Positioning → Fixture Sealing → Leak Test → OK/NG Determination → Automatic Sorting → Data Upload to MES. As a result, airtightness testing has evolved from a standalone quality inspection station intoKey Points in Production Line Quality Control. High-volume manufacturing companies can also adopt dual-channel, four-channel, or multi-station configurations to accommodate higher production rates.

Q10: Which industries does JCGK Jingcheng Engineering primarily serve?

Any industrial product with requirements for sealing, waterproofing, or leak resistance is included in the scope.

sector	Typical Products	Correspondence testing program
New Energy	Battery Case Cover, Cell Module, Battery PACK	Pressure Tightness Testing + Burst Testing + Helium Detection System
Home Appliances	Sealing components for water purifiers, dental scalers, and floor sweepers	Comprehensive function test + waterproof test
Auto Parts	Lamps, sensors, die castings, automotive wiring harnesses	Seal detection + flow monitoring
Consumer Electronics	Smartwatches, Headphones, Cell Phones, GPS Watches	Volumetric method + leak detection program
Medical Equipment	Ventilators, infusion lines, medication bottles, endoscopes	Low Pressure Seal Testing + Flow Leakage Analysis
Security Lighting	Cameras, LED Screens, Outdoor Lighting, Spotlights	IP65–IP68 Water Resistance Rating Testing
Valve Piping	Gas Valves, Capillary Tubes, Wire Connectors, Splices	Flow method + high pressure test program
Robot	Gearboxes, joint modules, servo motors, controllers	Low-Pressure Differential Detection + Specialized Oil Leak Testing Solution
Liquid Cooling	Liquid-cooling plates, water-cooling tubing, liquid-cooled CDU, cooling modules	High-Pressure Cycle Seal Validation + Micro-Leak Permeation Test
Aerospace and Defense	Precision valves, pressurized compartments, hydraulic systems, propulsion components	Extreme Environment Simulation Testing + Multiphysics Coupling Validation

Q11: SelectAirtightness TesterWhat are the most common pitfalls?

Consider only one parameter: precision.

Accuracy is certainly important, but what truly determines the effectiveness of the inspection is a combination of factors:Test Accuracy + Repeatability + Stability + Fixture Sealing Design + Pneumatic Circuit Design + Software Algorithms + Actual Test Results...all of which are essential. Temperature fluctuations, the stability of valve assembly seals, the product’s own volume, and material properties—these factors collectively influence the final testing performance—not just the accuracy specifications set during factory calibration.

Q12: Why are more and more companies choosing Jingcheng Engineering?

Industrial customers need more than just an instrument; they need a solution that can be implemented on the production line.

Shenzhen Jingchenggongke Technology Co., Ltd.(Abbreviation: JCGK, Jingcheng Engineering)As a leading company in the field of airtightness testing in China, with over a decade of experience in the field of seal integrity and waterproofing testing, our product line includes direct-pressure(Including positive pressure, negative pressure, and a combination of positive and negative pressures), differential pressure, flow,Volumetric Quantitative Leak Test Equipmentas well asNew Energy Test Equipmentand other series of specialized testing equipment(e.g.Waterproof Breathable Membrane Comprehensive Tester,Comprehensive testing system for water purifierscap (a poem)Safety Valve Testing Equipment(etc.), and also offersManufacturing Fixtures + Automation Integration + Data TraceabilityComprehensive solutions. For companies currently pursuing domestic substitution, the true basis for their decision is:A comprehensive balance of equipment performance, delivery responsiveness, customization capabilities, and long-term service, rather than simply the purchase price.

Q13: How can I quickly determine whether I need to perform an airtightness test?

Ask yourself these three questions. If even one of the answers is “yes,” it’s worth taking a closer look:

Is the product resistant to water, moisture, or air leaks?

Does the product have any sealed chambers or flow paths inside?

If a leak occurs, will it affect functionality, safety, or service life?

Conclusion

From lighting fixture housings to new energy battery casings, from automotive connectors to medical tubing—the items being tested vary widely, but the core principle remains the same:Ensure that the product's sealing performance meets the requirementsThe

A truly professional airtightness testing solution requires a comprehensive assessment.Product Design + Test Pressure + Permissible Leakage Rate + Inspection Cycle Time + Fixturing Method + Automation Requirements. JCGK Jingcheng Engineering provides manufacturing companies with comprehensive industrial inspection solutions, ranging from equipment selection to tooling, fixtures, and automation integration.

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Original Statement:this paper was written byShenzhen Jingchenggongke Technology Co., Ltd.Written by the technical team, reproduced with attribution.Data sources: Precision Engineering internal test data and customer cases.