Further, the method includes enlarging the hole until {HEAD ~ the sensed parameter} represents {TAIL ~ a preselected air flow rate} through the hole 
Further , the method includes enlarging the hole until { HEAD ~ the sensed parameter } represents { TAIL ~ a preselected air flow rate } through the hole
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH