Airtightness testing is a key part of verifying a product's airtightness. Excellent airtightness can ensure the safe and reliable operation of the product, and the choice of detection technology directly affects the detection 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.
Vacuum leakage detection, the smallest leaks can not escape the eye
Vacuum leakage detection will be tested after the product is pumped into a vacuum state, through the monitoring of the internal gas flow changes to determine the airtightness of the good or bad.
These technologies can be used to detect millimeter-level cracks. It is undoubtedly the best solution for critical spacecraft components, medical devices, and other scenarios that require extremely high levels of airtightness.
But we also need to pay attention to its limitations:
Not applicable to some products that can't be vacuumed
The detection cycle may be longer
Flat panel displays: Negative-pressure airtightness testing
Positive-pressure leakage detection, easy, fast and convenientPositive-pressure leakage detection uses high pressure to inflate the product and then detects the pressure. The positive pressure leakage detection first uses high pressure to inflate the product, and then detects the pressure decay to determine the airtightness. It has no special requirements on product structure, and the operation is fast and efficient. Positive pressure technology is the preferred choice 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
Wire harnesses: Positive Pressure Airtightness Testing
So, we should take into account the product attributes and usage scenarios, and choose the right The only way to achieve this is to understand each of the technologies and to use them in their own way. Only by understanding the advantages and disadvantages of each technology can we ensure the quality of our products.
How to choose a leak testerThere are two main testing instruments for vacuum leak detection:
1, helium mass spectrometry leak testerPrinciple: The product to be tested is pumped with helium, and then mass spectrometry is used to detect the rate of leakage of the helium gas remaining in the product. The size of the tiny cracks is calculated based on the pattern of helium escaping by collision.
Advantages: High detection sensitivity, can detect 3 × 10 Pa-m?/s level of tiny leak detection rate, locate the leak position.
Disadvantages: Expensive equipment and high cost of helium.
Helium mass spectrometry leak detection principle
2, negative pressure gas tightness testerPrinciple: with a pressure / flow sensor to monitor the product under test in a negative pressure environment pressure and flow rate changes, to determine whether the gas is leaking.
Advantages: Simple operation, stable and reliable, low cost.
Disadvantages: Detection sensitivity is slightly poor, can be detected with a minimum precision resolution of 1Pa.
JCGK negative pressure air tightness tester
Positive leakage detection of the main testing equipment there are two:
1, positive pressure air tightness tester<
Principle: Fill high pressure air to the product under test, detect the decay of internal pressure over time to determine the airtightness.
Advantages: Easy to operate, fast detection, good repeatability.
Disadvantages: Slightly less sensitive to small leaks.
Positive pressure leakage detection principle
2, volume quantitative leakage testerPrinciple: Measurement in a certain positive pressure, the unit time from the tested component out of the permeability of the gas volume.
Advantages: Simple system design, economical price, accurate results.
Disadvantages: Can only perform an overall gas tightness test and cannot locate leaks.
JCGK Quantitative Airtightness Tester
SummaryThis paper points out that the principle, equipment, advantages and disadvantages of the two leak detection technologies should be fully considered in the product attributes and use scenarios, and the appropriate airtightness detection strategy should be selected in order to ensure the effectiveness and quality of detection. It provides a new secret of airtightness testing with very practical reference value.
In terms of equipment selection, it is recommended to consider the industry's leading airtightness testing solution provider, JCGK Precision Engineering.
To learn more about the detailed airtightness testing program and application cases, please pay attention to JCGK airtightness