Investigation of drag effect using the field signature method

The potential drop (PD) method is an established non-destructive evaluation (NDE) technique. The monitoring of internal corrosion, erosion and cracks in piping systems, based on electrical field mapping or direct current potential drop array, is also known as the field signature method (FSM). The FSM has been applied in the field of submarine pipe monitoring and land-based oil and gas transmission pipes and containers. In the experimental studies, to detect and calculate the degree of pipe corrosion, the FSM analyses the relationships between the electrical resistance and pipe thickness using an electrode matrix. The relevant drag effect or trans-resistance will cause a large margin of error in the application of resistance arrays. It is the first time that the drag effect in the paper is investigated and analysed in resistance networks with the help of the FSM. Subsequently, a method to calculate the drag factors and eliminate its errors is proposed and presented. Theoretical analysis, simulation and experimental results show that the measurement accuracy can be improved by eliminating the errors caused by the drag effect.