heliumlektesten

Helium leak testing, or heliumlektesten, is a non-destructive testing method used to detect and quantify leaks in components and assemblies by using helium as a tracer gas. Helium is chosen because of its chemical inertness and very small atomic size, which allows it to pass through openings that may be imperceptible to other gases.

Principle and methods

The basic principle is to expose either the exterior or the interior of a test object to helium and then monitor for the presence of helium where it should not be. Leaks are detected with helium mass spectrometer leak detectors (MSLD) or with handheld helium sniffing devices. Test configurations include vacuum-based methods, where the part is placed in a chamber and a helium-containing environment is created on one side, and pressure-based methods, where the object is pressurized with helium or a vacuum is used to draw helium through leaks. Results are typically expressed as a leak rate in units such as atm·cm^3/s or Pa·m^3/s.

Applications

Helium leak testing is widely used in the automotive, aerospace, electronics, medical devices, packaging, and vacuum-system industries. It is employed to verify enclosures, seals, welds, gaskets, and components where maintaining a hermetic or leak-tight boundary is critical.

Advantages and limitations

The method offers high sensitivity, rapid results, and the ability to locate leaks with precision. It is non-destructive and applicable to complex geometries. Limitations include the need for helium supply, specialized equipment, and careful interpretation to avoid false positives from diffusion or background helium.

Standards and practice

Many industries follow standardized procedures and guidelines for leak testing to ensure consistency, accuracy, and traceability of measurements.