Hard Vacuum Leak Test
What is a Hard Vacuum Leak Test?
Hard vacuum leak testing (helium mass spectrometer leak detection) is the most sensitive production leak test available. The part is charged with helium and placed in a test chamber; vacuum pumps evacuate the chamber to a hard vacuum, and a mass spectrometer tuned to helium measures every atom that escapes the part. The result is the part’s total leak rate — every leak path counted at once — routinely resolving leaks from 10⁻⁹ down to 10⁻¹¹ mbar·l/s.
Because the measurement happens in a clean vacuum with virtually no background, hard vacuum testing is fast even at extreme sensitivity, and the result is completely independent of operator technique — ideal for automated cells testing hermetic and safety-critical parts. The same physics also works outside-in: an evacuated part or vacuum system can be sprayed with helium to find leaks in vacuum equipment. See all trace gas leak testing methods.
Here’s how it works:
- Charge — the part is evacuated, then filled with helium to its specified test pressure (a Zaxis Z-Charge manages evacuate → purge → charge automatically).
- Load — the part goes into the test chamber and the chamber seals.
- Evacuate — vacuum pumps take the chamber to hard vacuum, stripping away air and residual helium background.
- Measure — the mass spectrometer samples the chamber; any helium escaping the part registers as the part’s total leak rate.
- Judge & recover — the rate is compared to the reject limit for a definitive PASS/FAIL, then the chamber vents and the helium can be reclaimed.
A tight part holds the chamber at background; helium from a leaking part rises above the reject limit within seconds. Zaxis hard vacuum leak test systems sequence the entire cycle automatically.
Sample Applications:
- Implantable medical devices
- Hermetic electronics & sensors
- Airbag inflators & pyrotechnic devices
- Refrigeration compressors & components
- Fuel injectors & fuel rails
- Sealed batteries & battery cells
- Aerospace & defense components
Not sure whether your reject limit truly needs hard vacuum sensitivity — or whether accumulation or sniffing would do the job for less? Contact Zaxis — our engineers will size the right method for your spec.
Why Choose Hard Vacuum Leak Testing for Your Products
When the spec says hermetic, hard vacuum is the method that proves it. No other production leak test combines this sensitivity with this speed and repeatability.
- The ultimate sensitivity — 10⁻⁹ to 10⁻¹¹ mbar·l/s, orders of magnitude beyond any air-based test
- Total leak rate — every leak path measured at once, one quantitative number per part
- Fast cycles even at extreme sensitivity — clean vacuum means near-zero background and short test times
- Operator-independent — the chamber does the work, making it ideal for automated cells
- Audit-ready data — a recorded, calibrated leak rate for every serial number
- Helium reclaim — recovery systems keep gas cost under control in high-volume production
Contact Zaxis Inc today to build the right hard vacuum solution for your product.
Suggested Leak Testers For Hard Vacuum Testing
Helium leak detector for hard vacuum and sniff testing — calibrated reject limits and a clear PASS/FAIL for every part.
Prepares the part — evacuate, purge, and charge with helium to test pressure before the chamber cycle, identical every time.
The 8″ modular platform that sequences chamber, external vacuum source, and detector — and logs a quantitative result for every part.
Hard vacuum helium leak testing delivers the highest sensitivity of any production leak test, with quantitative, operator-independent results that stand up to the strictest quality audits in medical, automotive safety, and aerospace manufacturing. Zaxis builds complete hard vacuum solutions — charge station, chamber, vacuum system, and detector — engineered as one integrated cell. Explore all trace gas leak testing methods or request a quote to get started.