The present invention pertains to apparatus and methods for measuring {HEAD ~ potentials} between buried pipelines and {TAIL ~ the soil} wherein the pipelines are connected to a cathodic protection system and are disposed in urban areas, in particular 
The present invention pertains to apparatus and methods for measuring { HEAD ~ potentials } between buried pipelines and { TAIL ~ the soil } wherein the pipelines are connected to a cathodic protection system and are disposed in urban areas , in particular
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH 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