A new inducer for pipeline inner inspection based on ACFM

A new typed inducer is devised for alternating current field measurement (ACFM). A numerical simulation model of the inducer is built to observe the distribution of magnetic flux density near the crack, and a dynamic model is developed from it to model a real ACFM inducer passing a real pipeline with a crack. The dynamic model is verified by comparison with experimental data and shows good agreement. The influence of different parameters, such as the distance between inducer and pipeline, coil turns, coil current, the diameter of enameled wire and excitation frequency is modeled and discussed. Through the above research, the new typed inducer is verified to have a good accuracy for pipeline inner inspection.