1. Rigorous sealing

In order to set the standard for leak tightness, we propose to use the minimum leakage value detectable by the leak testing methods listed in the standard as the rigorous leak tightness threshold. NF EN 1779/A1 [1], i.e. a leakage flux value of less than 10 ^-9 Pa.m ^-3 .s ^-1 corresponding to the "vacuum box with tracer gas applied inside the object" method (B.2.1.).