The measured time represents the relative position of {HEAD ~ the transducers} along {TAIL ~ the magnetostrictive element} 
The measured time represents the relative position of { HEAD ~ the transducers } along { TAIL ~ the magnetostrictive element }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL