Calibration of Coating Area Resistance Assumptions in AC Interference Studies Using Real-Time Field Data

Abstract An alternating current (AC) interference study was conducted on an existing multi-pipe right-of-way (ROW) in which the baseline model results varied significantly from readings collected in the field. After a thorough investigation, coating quality assumptions were found to be the primary cause of the discrepancy. Due to the challenges associated with making accurate coating quality estimates on aging infrastructure with a variety of coating types and vintages, real-time field data was used to calibrate the modeled coating area resistance value to ensure the predicted results better aligned with real-world measurements. This approach allowed integrity risks and personnel safety hazards to be more accurately quantified and added a measure of validation to the design process that has historically been achievable only after system construction. An appropriately sized mitigation design was completed, addressing the concerns identified during the study while avoiding unnecessary construction costs. This paper discusses the approach to this method.