{HEAD ~ An apparatus} for checking {TAIL ~ the diameter} of a cylindrical part in orbital motion about a geometrical axis in a numerical control grinding machine, said apparatus comprising: 
for checking
{ HEAD ~ An apparatus } for checking { TAIL ~ the diameter } of a cylindrical part in orbital motion about a geometrical axis in a numerical control grinding machine , said apparatus comprising :
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH