Direct Pressure, Differential Pressure, Flow, True Water, Breathing, an article on all the mainstream technologies of airtightness

When faced with a product that requires airtightness testing, how would you choose the most appropriate testing solution?

It's not just about technology, it's about business decisions. There is a unique application logic and cost consideration behind each detection solution.Precision Engineering as a professional airtightness solution and testing equipment providerIn addition, we understand the differences in the needs of different customers, and therefore provide five core inspection solutions, each of which is tailored to specific application scenarios and technical needs.

Ⅰ. Selection matrix of technical options

Core judgmental dimensions

There are four core dimensions to consider when selecting an airtightness testing program:

dimension (math.)	key issue	factor
Detection accuracy	How much leak detection accuracy is needed?	Product sealing requirements, quality standards
Product Characteristics	Does the product need to be breathable? Is it completely sealed?	Structural design, functional requirements
production efficiency	What are the speed requirements for batch testing?	Production tempo, cost control
Problem orientation	Is there a need to pinpoint leaks?	Quality analysis, process improvement

Based on these four dimensions, let's deeply analyze the technical characteristics and application logic of the five major detection solutions.

II. Option 1: Straight Pressure Method - The King of Versatility

technological core

direct pressureIt is a "one-size-fits-all" solution for airtightness testing.(Positive pressure, negative pressure, positive and negative pressure, positive and negative pressure, volumetric quantification, negative pressure quantification, positive and negative pressure volumetric quantification of Precision Industry Corporationairtightness meterAll belong to the direct pressure method) The widest range of applications and the highest level of technological maturity.

Working Principle: Inflate/extract air into the product or special fixture chamber, shut off the air source after reaching the preset pressure, and monitor the pressure drop value to judge the sealing.

Technical Advantage Analysis

Perfect realization of non-destructive testing: It is entirely gas-based, eliminating any risk of liquid damage, which is especially important for electronics.

Scientific guarantees of quantitative accuracyThe leakage rate can be accurately measured to provide a scientific basis for quality grading, rather than a simple "pass/fail" judgment.

Natural advantages of automation integration: Short test cycles, perfectly adapted to the fast pace of modern production lines.

Best Application Scenarios

pertainVarious open-hole and fully enclosed products: Consumer electronics (e.g. smart phones, bracelets, code watches, waterproof speakers, etc.)Standard sealing products for automotive parts, medical devices, etc.

III. Option 2: Differential Pressure Method - The Choice of Accuracy Seekers

The internal logic of technological upgrading

differential pressureEssentially an upgraded version of the accuracy of the direct pressure method, environmental interferences are eliminated by the introduction of standard comparisons.

Working Principle: Simultaneous pressure testing of the standard and the test article to determine leakage by comparing the pressure difference between the two.

Unique value embodiment

Effective elimination of environmental disturbances: External factors such as temperature changes, air pressure fluctuations, etc. have the same effect on the standard and the test article, which can be effectively canceled out by difference calculation.

Significant improvement in detection accuracy: The ability to detect even smaller leaks makes it suitable for scenarios where high precision is required.

Technical support for high stress applications: Particularly suitable for seal testing in high-pressure environments.

Core application areas

focusing onHigh-pressure, high-precision products to be measured: Die castings, water-cooled plates, high-pressure containers, and other products that require extremely high sealing.

IV. Option 3: Flow Methods - Specialized Solutions for Vented Products

Fundamental differences in the philosophy of technology

flow rate methodThe solution is an entirely different problem: how to measure 'intentional leakage' - i.e. breathability.

Working Principle: Provides a constant test pressure to one side of the product and directly measures the gas flow through the product to quantify the rate of permeation.

Uniqueness of professional values

Precise quantification of breathability: It's not about determining leakage, but measuring the rate of air permeability, which is critical for breathable film products.

Functionality testing rather than sealing testing: Verify that the product has the breathability required by the design.

Specialized Application Scenarios

mainly used forCapillary tube, waterproof breathable membraneand its integrated products: breathable valves for outdoor electronic devices, breathable components for automotive lamps, etc.

V. Option 4: Airtight True Water Leakage Test - Return of Intuitiveness

A perfect blend of tradition and modernity

This solution represents a modernization of the traditional water measurement method, retaining the intuitive advantages and eliminating the traditional disadvantages.

Working Principle: The product is immersed in water, and bubbles are generated by pressurizing the water to visually locate the leakage point.

Irreplaceable technical value

Precise location of leaks: The bubbles directly mark the location of the leak, a visualization that no other method can provide.

Authoritative verification of IP rating: Particularly suitable for final validation of high waterproof ratings such as IPX7/IPX8/IPX9.

Strong support for problem analysis: Provides visual problem localization for quality problem analysis and process improvement.

Best time to use

pertainProducts that require precise location of leaks: Verification of waterproofness of electronic products and final confirmation of high waterproof grade products.

VI. Program V: Respiratory Cycle Fatigue Test - Guardian of Long-Term Performance

Technological extension of the time dimension

This program is not concerned with current sealing, but with maintaining performance after long-term use.

Working Principle: Repeated positive and negative pressure transitions are performed to simulate extreme use environments and to monitor the performance degradation process.

waterproof and breathable membraneRespiratory Cycle Fatigue Tester

Embodiment of predictive value

Scientific prediction of service life: Accelerated aging tests are used to predict the degradation of a product's performance in actual use.

Early detection of potential problems: Finding problems such as delamination and wrinkles that are not readily apparent in normal testing.

Specialized Application Areas

mainly used forProducts with Waterproof Breathable Membrane: Outdoor electronic equipment, automotive parts, and other products that require long-term reliability assurance.

VII. Solution System of Precision Industrial Technology

Full coverage of configuration flexibility

multichannel(also called multi-station)optionThe range is from single-channel to ten-channel, which meets different needs from R&D validation to mass production.

Number of channels	Applicable Scenarios	Efficiency features
Single/Dual Channel	R&D validation, small batch testing	High flexibility and low cost
Quad/Six Channel	Medium volume production	Balancing efficiency and cost
Eight/ten channels	mass produce	Maximizing Efficiency

Diversification of equipment forms::

• Desktop Split: Suitable for space-constrained laboratory environments
• Floor standing all-in-one: Suitable for long-term stable operation of production lines

The deep value of customized services

Specialized jigs and fixtures design: Tailored to product characteristics to ensure test stability and repeatability.

Fully automated integration: Provides complete automation solutions from loading to inspection to sorting.

VIII. A Practical Guide to Choice Decision Making

Quick Selection Flowchart

Does the product need to be breathable?
├─ Yes → Flow method
└─ No → Is it necessary to locate the leak?
    ├─ Yes → Airtight water leakage test
    └─ No → Is accuracy required?
        ├─ Yes → Differential Pressure
        └─ No → Direct pressure method

Does long-term reliability matter?
└─ Yes → Increase Respiratory Cycle Fatigue Testing

Cost-benefit analysis framework

Initial investment vs.::

• Equipment Cost: Differential Pressure > Flow Method > Direct Pressure Method
• Detection efficiency: multi-channel > single channel
• Quality assurance: real water testing provides the most intuitive value in locating problematic leaks

Summarize

In the field of airtightness testing, there is no one-size-fits-all solution, only the most suitable combination of technologies.Precision EngineeringThe system of five solutions is based on this philosophy: to make each technology maximize its value in the most suitable scenarios.

If you are looking for the most suitable solution for airtightness testing, we recommend you to contactPrecision EngineeringOur team of professionals will consult with you on customized solutions for your specific needs.

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.