{TAIL ~ Apparatus} for establishing electrical conductivity between {HEAD ~ a reference electrode} and soil under a pavement layer comprising: 
{ TAIL ~ Apparatus } for establishing electrical conductivity between { HEAD ~ a reference electrode } and soil under a pavement layer comprising :
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH