Q&A: What are the requirements for the environment in which the airtightness tester is used? Please take this checklist

The most common complaint heard on the production line is: "TheThe equipment is unstable, isn't it?airtight instrumentsProblems?"

The answers are often surprising:The instrument is fine, the environment is.The

But behind that answer lies an even harsher truth - theYou know there is something wrong with your environment, but it is difficult to actually change it.

Ⅰ. The laws of physics will not be compromised

Airtightness Testerworks based on a middle school physics equation:

PV = nRT (ideal gas equation of state)

This formula dictates an iron law:Any change in temperature, humidity, air pressure, etc. is recognized by the instrument as a pressure changeThe instrument itself, on the other hand, was unable to distinguish between a real leak and an environmental disturbance. The instrument itself, on the other hand, could not distinguish whether this pressure change came from a real leak, or an environmental disturbance.

In other words, the environment is not an auxiliary condition, but thePart of precisionThe

It's like weighing a milligram item on a balance; it's impossible to get an accurate reading outdoors on a windy day. It's simple, but often difficult to put into practice on the production line.

II. Environmental elements: the gap between ideals and reality

Temperature: the biggest unseen variable

ground PV = nRTFor every 1 °C rise in temperature, the air pressure in the closed chamber rises significantly, to an extent that may even mask the pressure change of a small leak.
Industry standard requires temperature 15~30 ℃, fluctuation ±1 ℃, high-precision scenarios require ±0.5 ℃.The
However, production line air conditioning, fans blowing directly, the temperature difference between day and night, workpiece waste heat and other problems prevail, to achieve constant temperature standards, often require independent constant temperature room, high cost.

Humidity: the underestimated invisible killer

Water vapor in the compressed air enters the air line and condenses on the sensor surface, directly causing data drift.
Standard requirements for humidity ≤85% RH, the gas source needs to be dried, filtered, stabilized pressure treatmentThe
However, the investment of a complete set of air compressor, cold dryer, three-stage filter, may be higher than the instrument itself; and most companies neglect maintenance, filter element clogging, cold dryer failure, will make the data chronic distortion.

Barometric pressure: a neglected baseline variable

Atmospheric pressure fluctuates dramatically with altitude and weather, and the difference in barometric pressure between rain and shine at the same location is equally significant.
High-end equipment such as Precision Engineering'sairtightness leak detectorAuto-compensating, manual calibration for low and mid-range equipmentThe production line will be adjusted to the weather on a daily basis.

Vibration: the forgotten source of interference

Vibrations from presses, injection molding machines, and assembly lines are transmitted to the inspection station, causing fluctuations in sensor signals and unstable workpiece seals.
The ideal solution is a stand-alone vibration-proof workstation, but it is difficult to realize in the inch production line.

III. Comparison of environmental sensitivity of three hermetic detection methods

Detection method	environmental sensitivity	Cause analysis	Accuracy level
Water test (immersion method)	lower (one's head)	Observe the bubbles and make a rough judgment	millimeter
Dry Leak Detection (airtightness meter)	mid-to-high	Measuring pressure changes	micron scale
Helium mass spectrometry (helium detector)	extremely high	Molecular level detection	nanoscale

This comparison reveals a cruel law:The higher the accuracy, the more sensitive it is to the environmentThe

Ⅳ. Difference between the standard configuration and the actual production line environment

Ideal environmental standards

Temperature: 25±5℃
Humidity: 40%-~70% RH
Gas source: drying + filtering + pressure stabilization
Workstation: no direct wind blowing + anti-vibration design
Product: Thermal equilibrium ≥ 10 minutes before testing

Common Fatal Mistakes

• Test the product directly after soldering(Temperature not equilibrated)
• Air Conditioning Direct Blow Test Position(Temperature fluctuations)
• No drying treatment of air supply(humidity disturbance)
• Multi-station temperature inconsistency(Systematic errors)

The consequences of these mistakes are:High false NG rate, difficult to adjust the machine, decreased line efficiency.The

More troubling, these problems don't result in equipment reporting errors or downtime, theIt only makes the test results unstable. The quality department and the equipment department are passing the buck to each otherThe problem has remained unresolved for a long time.

V. Engineering solutions: seeking equilibrium within constraints

The environment cannot be completely ideal, but it can be optimized at three levels:

Hardware layer: enhance the anti-interference ability of the device itself

• Adoption of high stability sensors(0.1 Pa accuracy)
• Use of low-drift manifolds
• Design of high sealing fixtures

These measures increase the cost of the equipment, but significantly reduce environmental dependence.

Software layer: algorithms to compensate for environmental changes

• Temperature compensation algorithm
• Automatic Drift Correction

Good software algorithms can offset environmental impacts to a certain extent, but cannot completely replace environmental controls. This istreat the symptoms but not the root causeprogram, yet it is often the least costly option.

System layer: establishing data traceability and process control

• MES Data Traceability
• SPC Process Control
• Early warning mechanism for anomalies

Discovering patterns of environmental problems through data management for targeted improvements. This requires a high level of information technology in the business.

VI. New options under the wave of domestic substitution

Under the current trend of domestic substitution to Shenzhen Jingcheng Gongke JCGK The domestically produced solutions represented by the company are developing a differentiated advantage:

Adaptation at the technical level

• Multi-principle coverage(positive pressure, vacuum, differential pressure, volumetric, flow, etc.)
• Built-in ambient temperature compensation algorithm
• Anti-interference design optimized for domestic production line environment

The advantage of domestic equipment does not lie in the leading technology, but in theBetter understanding of the actual environment of the production line in ChinaTheThe design of imported equipment is based on the standard environment of European and American factories, which is often not suitable for transplantation to China.The

Flexibility at the engineering level

• Rapid response technical support
• Customized Chemical Fitting Solutions
• Line Integration Capabilities(PLC/MES interface)

Domestic manufacturers can adjust the parameters and algorithms according to the actual environmental conditions of the customer, rather than requiring the customer to modify the environment to adapt to the equipmentThe

Rationalization of the economic dimension

It's not simply a low price, butTotal cost of ownership(TCO)dominance::

• Low initial procurement costs
• Low cost of spare parts and consumables
• Fast after-sales service response and short downtime

During the expansion or cost reduction phase, theThe balance of comprehensive stability, service response and overall cost became the core reason for enterprises to choose home-grown solutionsThe

VII. Practical checklist: the right order of problem identification

Do not rush to replace the equipment when there is drift in the detection data, a high rate of misjudgment, and difficulty in adjusting the machine. Troubleshoot in this order first:

1. Is the temperature stable? (24-hour temperature record at test station)
2. Is the air supply dry? (Check condition of cooler and filter)
3. Is there airflow interference? (Observe air conditioner and fan locations)
4. Is the product thermally balanced? (Freshly processed products need to be allowed to stand)
5. Are the workpiece seals good? (wear and aging check)

The problem with the 80% is the environment and the tooling, not theAir tightness testeritself.

Conclusion

The nature of airtightness testing is a game of accuracy versus cost.

As much accuracy as you want, you'll have to pay for the cost of environmental controls. The laws of physics are not compromised, but engineering solutions can be balanced.The

The smartest thing to do is not to strive for theoretical perfection, but to find, within practical constraints, theoptimal solution--Meet quality requirements while controlling overall costs and ensuring long-term stabilityThe

Original Statement: This article 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.