Close interval polarised potential surveys of buried pipelines: The truth

The technique of monitoring cathodic protection effectiveness on buried pipelines by the close interval ‘on‐off’ method is now well established. Many pipeline operators appreciate the need to have confidence in the true state of cathodic protection throughout a pipeline system rather than depending upon the often misleading measurements traditionally made at fixed test points, which at best can only provide information on levels of effectiveness in the immediate vicinity of the test point.