Application of Boundary Element Models to Predict Effectiveness of Coupons for Accessing Cathodic Protection of Buried Structures

Mathematical models were used to explore conditions under which a coupon provides a conservative assessment of the level of cathodic protection provided to holidays on coatings of buried structures. The most conservative assessment of cathodic protection was obtained when the area of the coupon was larger than the area of the largest expected holiday. The performance of the coupon as a monitor of cathodic protection was found to be influenced strongly by the availability of oxygen in the soil.