a height detector for detecting a height of {HEAD ~ a surface} of {TAIL ~ an object} to be inspected 
of
a height detector for detecting a height of { HEAD ~ a surface } of { TAIL ~ an object } to be inspected
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH