This eliminates {HEAD ~ the problem} of {TAIL ~ diffusion} of the lighter gas through the soap film as it travels from the gas flow inlet 25 to the sensor assembly 20, which in turn ensures that the soap film transits across the sensing region at the same rate as the gas 
of
This eliminates { HEAD ~ the problem } of { TAIL ~ diffusion } of the lighter gas through the soap film as it travels from the gas flow inlet 25 to the sensor assembly 20 , which in turn ensures that the soap film transits across the sensing region at the same rate as the gas
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH