The Pioneer of Modern Leak Testing

Test Method

Search for Testers by Technique

Many manufacturers want to insure their products are made to the highest quality and are leak tight. Either they are trying to contain a fluid from leaking out, be it liquid, air, or gas or they are trying to keep those fluids from entering their product. There are many different methods used in the leak testing industry to find a leak as a part of the quality assurance process.

There are many different factors that determine which type of leak testing method is best suited for a given application. That is where Uson can really help. We have the most experienced leak testing experts in the world, some with over 35 years of leak testing experience. Finding a product leak can be extremely difficult and knowing the best test method is critical for getting the best outcome.

We have listed most of the leak testing methods below. Each type has a short overview here with a ‘Read More’ link to learn more about the details of those methods. But, please be sure to contact a Uson leak testing expert and gain their experienced advice to help you find just the right solution.

Air Leak

Uson air leak testing equipment is available in a variety of different formats. Our wide range enables us to cover most applications with a tester specifically configured for the intended test. Operating modes include, pressure decay, mass flow, differential flow, pressure change, volume verification, occlusion testing, seal creep testing, and much more.

Air leak testing is clean, fast, non destructive and repeatable. Results of the leak test are non-subjective, requiring no operator interpretation and the data is easily exported to spreadsheet or other format for analysis and R&R studies. Leak detection using air as the test medium is the most popular automated method in use and the testers themselves are easy to use.

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Air Flow – Mass Flow

Mass flow or air flow testing uses flow measurement devices to calculate leak rates based upon the rate of air flow through the device. This technique is suitable for small and large volumes and is often applied to test kitchen appliances, gas meters, exhaust systems and other products where gas or air is required to flow through the item.

As a leak testing technique, mass flow measurement is very useful for detecting small leaks in large volumes. When selecting a mass flow tester it is important to select the correct flow meter range to ensure that the desired amount of sensitivity is achievable. Uson’s leak test application engineering group are available to help you with this.

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Pressure Decay

Pressure decay leak testing testing instruments are extremely useful for checking components that have relatively small volumes. The component is pressurized with air and the pressure transducer monitors the pressure for negative changes. Any pressure drop indicates a leak. The test is very fast, a matter of seconds, and is therefore popular in high-volume industries such as automotive components, castings, medical devices and consumer goods.

Sometimes this technique is referred to as gauge decay leak testing or absolute pressure leak testing because it basically measures the drop in pressure on a gauge (transducer) during the leak test.

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Differential Pressure

One of the fastest methods of leak testing, differential pressure decay is well suited for many applications. Like pressure decay, this method also involves measuring the drop in pressure inside the part over time as a result of escaping material. However, in a differential pressure test, the change in pressure is measured inside the part compared to the pressure inside a control volume charged to the same pressure as the part.

The differential pressure leak test, like the pressure decay test, is easy to set up, but can prove much more sensitive in certain leak testing applications. The sensitivity of the transducer is not related to the actual pressure in absolute or gauge pressure terms, but to the sensitivity of the differential pressure transducer at the test pressure.

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Functional Testing

Functional testing involves challenging the performance of an assembly against a set of predefined performance criteria. For example, a medical valve may have a torque to turn specification as well as a leak and flow test specification. Functional testers can be used to test valves, turbo chargers, electric motors, thermostats, electronic and mechanical control devices, medical devices, faucets, showers and many other components.

With powerful leak testers like Optima vT and Vector, Uson is able to utilize their formidable capacity to incorporate functional testing where possible. For example a leak test and operational test together with a flow test could be incorporated in a single Vector test station.

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Trace Gas Leak

Trace gas leak testers use a trace gas, often helium or sulphur hexafluoride, which is introduced into the product. These gases have very small molecules and can leak from the smallest leak path in various components, subassemblies and systems.

The trace gas leak test can be highly sensitive and unlike the other leak testing techniques this method can be used when it is desirable to locate the leak source. It is therefore a good technique when the possibility to take remedial action to stop a leak exists, for example in final assembly testing of engines.

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Flexible Packaging

Package testing is essential for ensuring integrity during packaging development, machine setup and quality control.

Pin holes, channel leaks and improper sealing all present challenges for leak testing in flexible packaging. The Uson Qualipak tester helps our customers perform clean, dry, non destructive and non subjective leak testing on a variety of flexible package types. Other Uson leak testers such as Qualitek mR and Optima vT can help test rigid containers such as bottles and jars. Custom leak test systems for packaging are also available.

At Uson, we provide non-destructive leak testing techniques for pouches and bags for use in the food, pharmaceutical, cosmetic and medical industries.

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Custom Solutions

Our design engineers are skilled in creating custom solutions. By working with you from the start, we ensure you benefit from the perfect balance of performance and power in your leak testing equipment.

In addition to the manufacture of independent test panels, we offer an in-house systems design and manufacturing capability that is able to produce fully-fixtured test beds for manual, semiautomatic or fully automatic leak testing of a wide variety of components.

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