In order to solve the low detection accuracy of pitting corrosion in field signature method(FSM),a mathematical model of subdivided resistor network was proposed to assess pitting corrosion by the analysis of the relationship between pitting corrosion,main and assistant voltages based on the influence on current distribution of pitting corrosion.Since different pitting corrosion with different positions,different depths or different diameters have certain different influences on main and secondary voltages,main and secondary voltages can be introduced to assess pitting corrosion.The essence of this method was to introduce a number of known parameters to calculate pitting corrosion which contains multiple parameters.Theoretical analysis and experiment results showed that this method can greatly improve the detection accuracy of pitting corrosion in FSM, and FSM is developed.
