Apparatus and {HEAD ~ method} for measuring {TAIL ~ potentials} through pavements for buried pipeline cathodic protection systems 
for measuring
Apparatus and { HEAD ~ method } for measuring { TAIL ~ potentials } through pavements for buried pipeline cathodic protection systems
OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH