There is a constantly growing need for products with hermetically closed elements, vessels and tubes. Envelopes with greater or smaller vacuum tightness had to assure a satisfactory isolation between external atmosphere and inside. Leak spots in closed systems are usually connections, gaskets, welded and brazed joints, defects in material etc.
Different leak testing methods and techniques are known, each testing is suitable only for a selected leak rate or for fixed forms and technologies
Halogen leak detectors are used in the detector-probe mode, requiring that the system be pressurized with a gas containing an organic halide. The exterior of the system is then scanned with a sniffer probe sensitive to traces of the halogen -bearing gas
Mass spectrometers as leak detectors are most sensitive instruments for leak detection. Helium is normally used as a tracer gas, because of its small mass and atom volume assures greater sensitivity