504 THE BELL SYSTEM TECHNICAL JOURNAL, MAY 19.54 



Fig. 5 — Capacitance test set and unit for tracking prol)c.s on cable surface. 



shown by Fig. 7. The sheath thickness is specified as the distance be- 

 tween the outside surface of the sheath to the bottom of the corrugations 

 formed into the polyethylene by the crests of the corregated metal 

 sheath, as indicated by dimension 7\ The top sketch shows the normal 

 amount of flood. The capacitance will be different in each of the three 

 conditions of equal thickness shown. With excess flood, center sketch, 

 the distance between plates is increased and the capacitance is decreased. 



