{HEAD ~ A proximity switch} may be employed to indicate {TAIL ~ the mold} being in position in front of the sound detector 
employed to indicate
{ HEAD ~ A proximity switch } may be employed to indicate { TAIL ~ the mold } being in position in front of the sound detector
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH