services | high vacuum leak checking

 

HIGH VACUUM LEAK CHECKING

Where a product requires gas tight integrity certification, we have the latest helium detection equipment.

Helium leak checking is performed to verify that where practical all our welds are gas tight. A helium leak checking instrument uses a mass spectrometer analysis cell tuned for the mass of a helium molecule to detect for the presence of helium.

Helium is a 'skinny' molecule having 2 protons, 2 neutrons and 2 electrons. It readily fits through small holes and cracks, as compared to a gas such as argon, which has 18 protons, 22 neutrons, etc. Helium is also readily available and is not regulated or toxic.

The principle of testing is that all the air is pumped out of the vessel creating a vacuum. Helium is sprayed around the outside. As the helium molecule is small it is 'pulled' into the chamber by the vacuum (the pressure inside being lower than the pressure outside). The path of the air to the pumps which create the vacuum is through the mass spectrometer. Any helium pulled into the system is pulled through the detector and can subsequently be measured.

The use of this system by our trained personnel ensures the gas tight integrity of all our vessels.

 

services | high vacuum leak checking