In addition, for lighter than air gases flowing into tube 22, {TAIL ~ the entire internal volume} of {HEAD ~ tube} 22 is filled by this inlet gas and the heavier air cannot diffuse upwardly of leg 27 across branch 28 and down leg 23 into the sensor area and below 
In addition , for lighter than air gases flowing into tube 22 , { TAIL ~ the entire internal volume } of { HEAD ~ tube } 22 is filled by this inlet gas and the heavier air can not diffuse upwardly of leg 27 across branch 28 and down leg 23 into the sensor area and below
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD 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