Pipe to soil potential measurements may be made without penetrating the pavement and without trailing {HEAD ~ wires} between the point of connection to the pipe and the available point of connection between the reference electrode and {TAIL ~ the soil} 
Pipe to soil potential measurements may be made without penetrating the pavement and without trailing { HEAD ~ wires } between the point of connection to the pipe and the available point of connection between the reference electrode and { TAIL ~ the soil }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL