Helium tracer gas is used for several leak testing applications. It has a small atomic size that allows the gas to pass though incredibly small leaks and is also non-toxic and non-flammable. One common method of tracer gas leak detection is the hard vacuum test, which involves the use of vacuum chambers and tracer gas to detect microleaks.
This method uses a portable leak detection system that consists of:
- A vacuum chamber or device
- A pump for evacuating atmosphere from the part and/or chamber
- A mass spectrometer for measuring the mass of helium in or around the part
- For additional functionality a sniffer wand can be added for leak location
Benefits of Using the Helium Hard Vacuum Test for Low Leak RatesHard vacuum helium leak testing is the most accurate and efficient of all tracer gas leak detection systems and is used in production leak testing to test parts with very low (extremely small) leak rates. It provides better repeatability than other tracer gas leak detection methods, offers shorter cycle times, and is less susceptible to temperature and other external environmental factors.
Using the vacuum leak test method provides benefits including:
- Extreme sensitivity detects leaks up to 1 x 10-8 scc/s
- High repeatability and fast cycle time
- Very high leak detection accuracy reduces false leak failures
Helium hard vacuum tests provide reliable results for testing a range of parts including sensors, housings, medical devices, sealed components, electrical housings, HVAC and refrigeration components, and more. The systems can be configured to match the complexity of virtually any testing application and to accommodate manual or automated loading.
Contact us to learn more about vacuum leak testing and other tracer gas leak detection solutions.
Vacuum Helium Leak Tests Provide a High Level of AccuracyVacuum helium leak tests can be performed using an “inside-out” or “outside-in” method. In an inside-out vacuum leak test, a part is placed in a sealed chamber and secured. A vacuum pump is then used to remove all the atmosphere from the chamber and part. After a sufficient vacuum is reached, the test cycle begins.
A mass spectrometer is used to sample the chamber for helium while the part fills with helium to test pressure specifications. As the part fills, the mass spectrometer continuously samples for tracer gas escaping from the part, analyzing the helium molecular flow compared to the reject set point for the test. If helium measurements exceed the reject specification, the part fails the leak test.
The outside-in hard vacuum test is performed outside of a chamber and involves evacuating the part and spraying helium gas around the exterior. If any leaks are present, the gas will flow to the interior of the part and be detected by the mass spectrometer, resulting in the part failing the leak test.
Both methods provide similar benefits, but the inside-out hard vacuum test can provide a higher level of sensitivity and has a reduced chance of human error since the testing process is automated. This makes it ideal for aerospace and other applications that require a higher level of accuracy. Cost is also a consideration, however, as it requires more equipment than an outside-in method performed with a sniffer wand.
Learn More About Hard Vacuum Helium Leak Test Systems
We provide helium vacuum leak test systems and a broad range of other tracer gas equipment including recovery systems, tracer leak standards, and much more. Request a quote today or contact us for more information.