The method also includes the step of sensing a parameter representative of {HEAD ~ air flow} through {TAIL ~ the hole} 
through
The method also includes the step of sensing a parameter representative of { HEAD ~ air flow } through { TAIL ~ the hole }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL