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