The Fallibility of Data Using Permanent Reference Electrodes

Permanent or buried reference electrodes are installed alongside coated pipelines with the primary intention of being able to accurately monitor local pipe to soil potentials.  Research undertaken over the past two years has shown that this is not necessarily the case.  The key element of the field research was to determine if coating holidays, at a distance (up to 20 or more feet away), were capable of having a significant affect on the pipe to soil potential thought to be accurately recorded adjacent to the reference electrode.  The field research included consideration of coating holiday size, proximity to the reference electrode and relationship with the ground voltage gradients due to cathodic protection current flow.