Helium Leak Testing Service

Tracer gas leak testing for industrial, automotive and aerospace manufacturers — on site or in our facility.

Helium Leak Testing and Tracer Gas Services

Helium leak testing is the most sensitive practical method available for verifying the integrity of sealed components. Helium is inert, non-toxic, present in the atmosphere at only ~5 ppm, and has an exceptionally small molecule — so it migrates through leak paths that air-based methods cannot resolve, and any helium detected outside the part can be attributed to a genuine leak.

Optimeasure has provided tracer gas leak testing since 1993. We supply the instruments, integrate them into production lines, and deliver testing as a service where you need capability without capital outlay.

Tracer Gas Test Methods

▶ Which method suits your part?

Method	How it works	Typical sensitivity	Best for
Vacuum (hard vacuum)	Part is evacuated inside a chamber; a mass spectrometer measures helium drawn through any leak	To 10⁻¹² mbar·l/s	Highest sensitivity; whole-part integrity; end-of-line automation
Accumulation	Part is charged with helium inside a sealed enclosure; helium concentration builds and is measured	10⁻⁶ to 10⁻⁷ mbar·l/s	Quantified leak rate without a hard vacuum system
Sniffing	Part is pressurised with helium; a probe is passed over the exterior to locate the leak	10⁻⁶ to 10⁻⁷ mbar·l/s	Locating leaks; large or awkward assemblies; in-service testing
Bombing	Sealed part is pressurised in a helium environment, then tested for escaping helium	To 10⁻⁹ mbar·l/s	Hermetically sealed items with no test port

Vacuum tells you whether a part leaks and by how much; sniffing tells you where. Many programmes use both — quantify first, then locate.

Standards We Test To

ASTM F2391 — standard test method for measuring package integrity by helium tracer gas.
ISO 20485 — non-destructive testing, leak testing, tracer gas method (superseded EN 1779).
ISO 20486 — calibration of reference leaks for gases, underpinning traceable results.
ISO 15848-1 — fugitive emissions classification for industrial valves.

See also our comparison of helium vs hydrogen leak detection.

When to Choose Tracer Gas Over Air

Air-based pressure decay leak testing is faster and cheaper per test, and is the right answer for the majority of production leak specifications. Tracer gas becomes the correct choice when:

Your specification requires better than roughly 10⁻⁵ mbar·l/s, which is beyond the practical reach of air decay.
The part volume is large, making air decay slow and thermally sensitive.
You need to locate a leak, not just detect one.
The part is hermetically sealed with no test port.
Regulatory or customer requirements specify a tracer gas method.

Where helium cost or supply is a constraint, forming gas is a proven alternative — see hydrogen leak detection.

Industries We Serve

Automotive and EV (battery cooling, fuel systems, powertrain), aerospace (fuel tanks, hydraulics, hermetic connectors), medical device and pharmaceutical packaging, HVACR and refrigeration, semiconductor and vacuum equipment, and general industrial pressure and vacuum vessels.

Equipment Supply and Integration

Alongside the service, we supply the INFICON leak detector range and integrate systems into existing production lines and PLC environments, backed by traceable calibration and a UK-wide service network.

Enquire About Helium Leak Testing »

Frequently Asked Questions

Why is helium used as a tracer gas?

Helium is inert and non-toxic, has a very small molecule that passes through tiny leak paths, and occurs in the atmosphere at only about 5 ppm. That low background means helium detected outside a part can be confidently attributed to a real leak rather than ambient contamination.

How sensitive is helium leak testing compared with air?

Considerably more sensitive. Air-based pressure decay is practically limited to around 10⁻⁵ mbar·l/s; helium vacuum methods reach 10⁻¹² mbar·l/s, with accumulation and sniffing typically 10⁻⁶ to 10⁻⁷ mbar·l/s.

Do you offer testing as a service, or only equipment?

Both. We supply and integrate INFICON leak detection equipment, and we also carry out tracer gas leak testing as a service — useful for validation work, short runs, or capability you need without capital investment.