Conversion of helium leak rate at laminar flow to leak rates of other gases

convert to:
q of Argon
q of Neon
q of Hydrogen
q of Nitrogen
q of Air
q of Water Vapour
multiply helium leak rate by factor:

As can be seen from this table, the difference of leak rate of air is only 7.7% than helium, smaller than the accuracy of a helium-leakdetector. If we consider a leaktest with a helium/air mixture under laminar flow conditions, then the measured helium leakrate can be regarded as the same as the air leakrate. For example, in a test carried out with a 10% Helium / 90% Air mixture, the measured Helium leakrate is 10% of the total leakrate, which from the above table is:

(0.9 x 1.077) + (0.1 x 1) = 1.069

This shows an error of 6.9% taking the viscosity of air a 1.