Structure borne sound sensors or {HEAD ~ ion current sensors} may also be used to detect a variable characterizing {TAIL ~ the combustion} in a combustion chamber 
Structure borne sound sensors or { HEAD ~ ion current sensors } may also be used to detect a variable characterizing { TAIL ~ the combustion } in a combustion chamber
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH