Effect of Receiving Coil Position on Detection Sensitivity in Pulsed Eddy Current Testing

Effect of the detection sensitivity caused by the location change of the receiving coil is studied on the internal corrosion of ferromagnetic pipe under insulation with pulsed eddy current(PEC) non-destructive testing. Finite element model was established of ferromagnetic pipe under insulation to analyze the effect of position of receiving coil on the pulsed eddy current testing results. The simulation results show that the sensitivity will reach maximum both axial and circumferencial directions when receiving coil is right under the outer edge of the exciting coil, the sensitivities 0.61 and 0.60 respectively. The verification experiment results show that: putting receiving coil right under the outer edge of the exciting coil will get the best test results, the sensitivities 0.26 and 0.27 respectively. The experimental results agree well with the simulations and show that the detection sensitivity will reach maximum when receiving coil is right under the outer edge of the exciting coil, which will be of help to probe design in the corrosion detection of the pipe under insulation with PEC.