Direct pressure method VS volumetric method, airtightness testing equipment in the end how to choose? Precision Industrial Technology in-depth analysis

In the modern manufacturing industry, whether it is new energy batteries, consumer electronics, automotive parts or waterproof parts for home appliances, "air tightness testing" is a key link to ensure product quality and safety.

But when faced with different structures, many engineers ask:Should I go with the direct pressure method or the volumetric method for my product?

Today, let us through the Jingcheng Industrial Technology (JCGK) industry testing experience, thoroughly clarify the differences between the two test methods and application scenarios.

Ⅰ. Two major categories of products for airtightness testing: open hole and fully enclosed

In practice, the products we encounter can be broadly categorized into two groups:

- Totally enclosed products: The exterior is completely sealed with no inflation holes.
👉 typical example: Tablet PCs, water meters, battery modules, electronic sensors, etc.

- Open Hole Products: Surface with inflation holes, exhaust holes or test ports.
👉 typical example: Valve bodies, connectors, plastic parts housings, headlight housings, etc.

Precision EngineeringVolumetric Quantitative Air Tightness TesterSupports both direct pressure and volumetric test modes.

For products with open hole construction, theDirectly inflatable/extractable internal test; whereas fully enclosed products requireIndirect testing of sealing by means of "equivalent volume".The

These two different structures are the watershed between the direct pressure method and the volumetric method.

II. Direct pressure method: an efficient inspection program for open-hole products

"Direct pressure method."(also called positive or negative pressure method)It is the most commonly used and intuitive method of airtightness testing.
It monitors the amount of pressure change in real time by filling/withdrawing a certain amount of air pressure inside the product to determine if there is a leak.

At Precision Engineering'sStraight Pressure Type Air Tightness GaugeThe detection pressure, leakage pressure and time parameters for each phase can be set flexibly.
When the product is placed on the work fixture, the system automatically inflates, stabilizes the pressure and collects the leakage signal.
Upon completion of the test, the instrument will visually display "PASS" or "NG" results, accompanied by sound and light prompts.

✅ Scope of Application:Open-ended products with inflation holes or air connections
✅ Advantage:Fast, accurate, easy to integrate, easy to operate
✅ Typical Scene:Valve housings, automotive parts, security housings, charger housings, etc.

III. Volumetric Method: The Way to Accurate Detection of Fully Enclosed Products

When the product is completely closed and there is no connection for inflation, the "Volume Method" test is used.

Instead of inflating the product directly, this method places the product into a closed test chamber and determines the amount of leakage by comparing the change in chamber pressure.

Precision Engineering'sVolumetric Quantitative Air Tightness TesterCan be switched to "Quantitative Test Mode" in the system settings.
At this point, the instrument automatically calculates the equivalent volume of the product under test and completes the accurate test in a non-porous state.

✅ Scope of Application:Fully sealed construction products
✅ Advantage:No need for product modification, high accuracy, data traceability
✅ Typical Scene:Tablet PC, water meter, camera module, battery case

Ⅳ. Semi-closed products: the ideal solution for dual-mode detection

In many actual factory cases, the product is neither completely open nor completely closed, and is a "semi-closed structure".
In response to this situation, Precision Engineering'sPositive pressure + negative pressure + volume quantitative typeAirtightness TesterDual-mode detection can be realized by one machine.

This kind of equipment supports positive pressure, negative pressure, volume quantitative multiple modes of switching, can be flexibly adapted to different stages (such as semi-finished products or finished products) of the detection needs, truly realize theFull Scene CoverageThe

Whether it's case testing for new energy battery modules or structural verification for consumer electronics, JCGK's multi-functionalairtightness meterAll provide stable and reproducible test results.

V. Precision Engineering: from the test principle to the application of the landing of the whole solution experts

As a leading domesticAir tightness testing equipmentManufacturer, Precision Industrial Technology has been deeply engaged in the industry for more than ten years, always focusing on the actual needs of customers and continuous innovation.

Currently, the JCGK product line is covered:

• Airtightness Tester,Waterproof Tester,Leak test equipment,Airtight water leakage tester
• Burst Tester,Respiratory Cycle Tester,Shell Withstanding Voltage Tester,Core pull burst water inspection machinecap (a poem)Helium detection equipment
• Waterproof Breathable Membrane Flow Tester,True Water Tester,Respiratory Cycle Fatigue Tester
• Water purifier comprehensive function testing system, safety valve testing system, etc.

Serving more than3600 homesOver200 homes(math.) genusOur products are CE certified and are exported to Asia Pacific, Europe and North America.

sth that one relies onStrong R&D capability, high cost performance, perfect after-sales systemJingcheng Industrial Technology has become a long-term technical partner of many manufacturing companies in the airtightness testing process.

Summarize

The principle of hermetic testing is not complicated, but choosing the wrong equipment can distort the test results and even cause quality risks.
Mastering the difference between the "direct pressure method" and the "volumetric method" is the first step for every engineer to become a selection expert.

JCGK has always been based on the concept of "Precision in Inspection, Sincerity in Engineering".Provide accurate and reliable seal testing solutions for customers in various industriesThe company is a leading manufacturer in China, helping Chinese manufacturers to move towards a higher standard of intelligent quality control.

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.