Thanks Ed...
It is high pressure in most cases (200 barg) for for corrosive and toxic service in process systems. Yes, mass spect is there but no assurance on the composition of N2/He mixture
All,
Having a leak rate acceptance criteria of 50 SCF/y in a mixture of 99% Nitrogen/ 1% helium for leak test of process piping, shall such criteria be different if the presence of helium by composition in the mixture is not guaranteed to be 1%?.
I appreciate your valuable feedback.