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