Best Practice Guide for Selection of Airtightness Testing Equipment, Comprehensive Comparison of the Advantages and Disadvantages of Vacuum & Positive Pressure Leak Detection

Airtightness testing is a key part of verifying the airtightness of a product. Excellent airtightness can ensure the safe and reliable operation of products, and the choice of testing technology directly affects the testing effect. In this article, we will introduce vacuum leakage detection and positive pressure leakage detection - the two major airtightness testing technologies recognized by the industry, and share the secrets of selection to help you upgrade your products.

Ⅰ.Vacuum Leak Detection, Even the Smallest Leaks Can't Escape the Eye

Vacuum leakage testing will be tested products into a vacuum state, through monitoring the internal gas flow changes to determine the airtightness of good or bad.The sensitivity of this technology is as high as to detect cracks of millimeters. It is undoubtedly the best solution for scenarios that require extremely high airtightness, such as critical components of spacecraft and medical device products.

But we also need to be aware of its limitations:

• Testing cycle may be long
• Not applicable to some products that cannot be vacuumed

Flat Panel Display: Negative Pressure Airtightness Testing

Ⅱ.Positive pressure leak detection, easy to operate, fast and convenient

Positive Pressure Leak Detection first uses high pressure to inflate the product, and then detects the pressure decay to determine the airtightness.It has no special requirements for the product structure and operates quickly and efficiently. Positive pressure technology is preferred for airtightness testing of many everyday products such as automotive components.

Of course there are disadvantages:

• Low probability of detecting small leaks
• Large error in results at high and low temperatures

Temperature sensor airtightness tester, support leakage rate and leakage amount two kinds of leakage judgment

Therefore, we should fully consider the product attributes and use scenarios to choose the appropriate airtightness testing strategy. Only by truly understanding the advantages and disadvantages of each technology can we prescribe the right medicine to ensure the quality of product inspection.

III.airtightness testerHow to choose

There are two main testing instruments for vacuum leak detection:

1、Helium mass spectrometer leak detector

Principle:The product under test is evacuated and filled with helium, then the rate of helium leakage remaining in the product is detected using mass spectrometry. The size of the tiny fissures is calculated based on the pattern of helium escape by collision.

• Advantage:High detection sensitivity, can detect 3 × 10-¹³Pa-m³/s level small leak detection rate, locate the leakage position.
• Drawbacks:Expensive equipment and high cost of helium.

2,Negative pressure air tightness tester

Principle:A pressure/flow sensor is used to monitor the pressure and flow rate changes of the product under test in a negative pressure environment to determine if the gas is leaking.

• Drawbacks:Slightly less sensitive, with a minimum resolution of 1 Pa.
• Advantage:Simple operation, stable and reliable, low cost.

Fourth, there are also two types of main testing equipment for positive pressure leak detection:

1,Positive Pressure Airtightness Tester

Principle:Fill the product under test with high-pressure air and detect the decay of the internal pressure over time to determine the airtightness.

• Drawbacks:Slightly less sensitive to small leaks.
• Advantage:Easy to operate, fast detection and good reproducibility.

2,Volumetric quantitative air tightness tester

Principle:Measurement of the volume of gas permeating out of the component under test per unit of time at a given positive pressure.

• Advantage:The system is simple in design, economical in price and accurate in results.
• Drawbacks:Only an overall airtightness test can be performed, and the location of the leak cannot be localized.

V. Summary

By comparing the principles, equipment, advantages and disadvantages of the two leakage detection technologies, this paper points out that the product attributes and use scenarios should be fully considered to choose the appropriate airtightness detection strategy in order to ensure the detection effect and quality. Provides a very practical reference value of the airtightness detection of new tips.

For equipment selection, we recommend considering JCGK, the industry's leading provider of airtightness testing solutions.

In addition to the above instruments, JCGK has developed its own advancedAirtightness testing equipmentsuch as fully automatedPositive and negative pressure leakage tester,Differential Pressure Airtightness TesterHigh sensitivityGas Flow DetectorThese instruments provide excellent performance and higher accuracy. These instruments can be configured to provide customized airtightness testing solutions.

At the same time, JCGK also has a professional technical service team, which can provide the best airtightness testing solutions according to the characteristics of the customer's products and testing requirements. By choosing JCGK, you can help your company to effectively improve the level of product development and manufacturing.