Product sealing waterproof leakage standard how to determine? Jingcheng Gongke airtightness tester setup method

In the manufacturing industry, whether it is consumer electronics, automotive parts, or medical devices and new energy power batteries, theSealing and waterproofing of the productAll are critical quality indicators.

How to scientifically determine if a product is 'leaking' or 'leaking'? How to useAirtightness TesterCorrectly set the judgment criteria? This is a practical problem that engineers often encounter. Below.Precision EngineeringCombined with industry experience, we will explain it to you in detail.

I. Correct understanding of product leakage

What is the nature of the leak?

Leakage is not simply a matter of 'leakage' vs.Mass transfer processes at the molecular level. Gas molecules migrate through material defects, seam gaps, molecular diffusion, and other pathways.

Key cognitive shifts: From "completely sealed" to "acceptable leakage rate"

There are no absolutely sealed products, only qualified products with an acceptable level of leakage.The determination of this acceptable range needs to be based on the actual usage scenario of the product.

Usage scenarios determine leakage tolerance

Product Type	Key usage scenarios	Leakage Tolerance Logic	Typical standard ranges
smartwatch	Waterproof for daily use, swimming	Full protection for a short period of time	50~100 Pa
Car Battery Pack	Long-term outdoor use	Slow leakage over a long period of time is acceptable	100~300 Pa
Medical Equipment	Long-term work in the body	Very low leakage requirements	20~50 Pa
Precision Die Casting	High-pressure working environment	High safety requirements	200~500 Pa

Normal Distribution Analysis of Goods Data

The traditional method of just looking at the 'maximum float' is not enough, a complete statistical analysis is needed:

Data Acquisition Requirements::

• sample size: At least 30 good samples
• test condition: Same temperature, humidity, and pressure conditions
• time span: Coverage of production variations in different batches

Calculation of statistical parameters::

μ (mean) = Σxi / n
σ (standard deviation) = √[Σ(xi - μ)² / (n-1)]

Upper control limit (UCL) = μ + 3σ
Lower Control Limit (LCL) = μ - 3σ

Standard setting based on 6σ quality management (Six Sigma)

Recommended standard setting formula::

Upper limit of determination = μ + 2.5σ
Warning line = μ + 2σ
Target value = μ

This method of setting ensures that:

• 99.38% yield pass rate(assuming normal distribution)
• Reasonable margin of safety(2.5σ level)
• Statistical reliability

Second, how to determine the sealing waterproof leakage standard?

1. Reference products and customer requirements
   • There is no standardized absolute value for leakage criteria for different products, but it is based on theProduct Characteristicstogether withclient requestto set.
   • For example, consumer electronics may only allow a few tens of Pa to leak, while large automotive parts may allow hundreds of Pa.

Electronic products waterproof horn airtightness test case, test pressure 15kPa, allowable leakage standard 30Pa

2. benchmark sth. against good quality

• First choose a proven "good" product and make sure it doesn't leak (can be verified by underwater immersion test or prolonged hydrostatic pressure test)The
• Test the good inAirtightness Testeron the value, the maximum float value is recorded. For example, the good leakage value floats at20~50PaBetween.

3. Creating "micro leakage products" for comparison

• An artificially created product with tiny sand holes or defects is used to simulate a defective product.
• Test their leakage values, which tend to be higher than good products, such as80~100PaThe

4. Setting the upper limit of judgment

• If the maximum floating value of the good product is50PaThe standard of determination is generally set at60~80PaThe
• Once the measured value exceeds this threshold, it can be judged as NG (Failed)The

III. How to use Seishin EngineeringAirtightness TesterSetting?

Basic Parameter Configuration

Step 1: Standardization of environmental conditions

Temperature control: 20±2℃
Humidity control: 45-65% RH
Pressure stabilization time: ≥10 seconds
Test pressure: set according to the product pressure resistance and testing requirements

Step 2: Benchmark data collection

1. Setting target pressure
   • According to the product pressure range and testing needs, first set the inflation pressure. (e.g. 50kPa, 100kPa, etc.)The
2. Acquisition of yield data
   • Take samples from at least 3 different batches, 10 samples from each batch, 30 or more samples in total, and record the leakage fluctuation range. (e.g. ≤50 Pa)The
3. Setting the Leak Determination Value
   • Enter the determination threshold in the instrument:
     • upper value: Slightly higher than the maximum value for good products, e.g. 60 to 80 Pa.
     • lower value (Optional): Avoid excessively low readings and troubleshoot sensor abnormalities.
4. Verification of the validity of the decision
   • Use of defective products (microleakage products) Test to make sure they trigger NG alarms.
   • If the NG product is not recognized, the threshold needs to be adjusted.
5. Save Parameters & Create Standards
   • The final threshold is saved as an assay process parameter and it is recommended that a standard good be used for periodic calibration to ensure stable and reliable results.

IV. Examples of practical application scenarios

Consumer Electronics Industry

Smartwatch waterproof standard setting case::

Good data: μ = 15Pa, σ = 5Pa
Judgment upper limit: 15 + 2.5×5 = 27.5Pa → Set to 30Pa
Warning Line: 15 + 2 x 5 = 25Pa

Verification results: Defect detection rate 99.2%, false positive rate 0.1%

Automotive

New energy battery pack sealing standard::

良品数据：μ = 80Pa, σ = 25Pa
判定上限：80 + 2.5×25 = 142.5Pa → 设定为 150Pa
分级管理：
- A 级品：≤100Pa（优秀）
- B 级品：100-130Pa（合格）
- C 级品：130-150Pa（临界合格）
- NG 品：>150Pa（不合格）

New Energy Vehicle Power Battery PackAir tightness testing equipment

In these scenarios, thePrecision EngineeringAirtightness TesterIt supports positive pressure method, negative pressure method, volumetric method, flow method and differential pressure method, and can flexibly set the threshold value, and link with MES system to realize the traceability of inspection data, which can meet the quality control needs of different enterprises.

V. Frequently Asked Questions (FAQ)

Q1: Can leakage standards be applied directly to industry standards?
A: Not recommended. Different products and customer needs vary and should beActual Goods Data + Industry NormsAs a reference.

Q2:Airtightness TesterHow often do the thresholds need to be adjusted?
A: Regular calibration with "Standard Goods" is recommended. (e.g., when changing processes on a weekly or batch basis)The

Q3: Can Precision Engineering assist in the development of leakage standards?
A: Yes. Precision Engineering not only providesAir tightness testing equipmentWe can also assist in the development of determination values and complete inspection programs that incorporate the customer's process and industry standards.

Summarize

The setting of standards for determining product leakage is not a simple numerical determination, but a scientific management of product quality. A good standard should:

Balancing multiple objectives: Quality assurance, cost control, production efficiency
Based on scientific evidence: Physical mechanisms, statistical principles, engineering verification
Continuous Improvement Optimization: Data-driven, closed-loop feedback, dynamic adjustment

If you want to establish a scientific leakage determination standard system, Jingcheng Engineering provides professional technical consulting and solutions. We not only provide advancedAir tightness testing equipmentWe will help you to establish a scientific quality management system, and more importantly, help you to establish a scientific quality management system.

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.