Testing and Evaluation of Decoupler Capacitive Effects

Confirming effective cathodic protection on a target structure involves verification of accurate measured potentials to compare against industry criteria. This is often performed via an interrupted survey to remove certain errors, yet a capacitive effect on these readings may remain in place due to the presence of decouplers. The purpose of this paper is to inform the reader of the issues involved, focusing on testing methodologies applicable to evaluating decoupler effects in the field, leading to correct product selection and appropriate survey settings appropriate for a successful survey. This considers conventional Dairyland decouplers, the Dairyland model PCRX, and testing with no decouplers in place. Safety aspects are also discussed in the course of the testing regimes.