measuring air pressure in the air cup, {HEAD ~ the air pressure} being directly related to {TAIL ~ the density} of the insulation 
directly related to
measuring air pressure in the air cup , { HEAD ~ the air pressure } being directly related to { TAIL ~ the density } of the insulation
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH