A controller unit receives and verifies whether the detection signal is within, or is outside of, {HEAD ~ a preselected range} of {TAIL ~ air pressure} 
of
A controller unit receives and verifies whether the detection signal is within , or is outside of , { HEAD ~ a preselected range } of { TAIL ~ air pressure }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL