LEAK TESTING SYSTEMS WITH TRACE GAS HELIUM

Leak testing systems with trace gas Helium? The helium leak test is based on the detection of helium as a test medium, which only occurs in extremely small quantities of around 5 ppm in the natural ambient air. Therefore, the detection of even the smallest helium concentrations enables a precise assessment of the tightness. A mass spectrometer is used to detect the test gas, which is capable of detecting minimal quantities. As a result, leak rates of less than 1x10^-8 mbar l/s (less than 0.01 µm) can be reliably measured.

As a rule, the test chamber is evacuated and the test object is pressurized with helium. The helium escaping through leaks spreads rapidly in a vacuum and reaches the detector within fractions of a second. It is also possible to work at atmospheric pressure; in this case, however, the gas must be mixed by means of fans, which leads to a significant increase in the minimum detectable leak rate. Before the actual helium leak test, a rough leak measurement is usually carried out first, which is integrated into the testing systems as standard.