RFT Signal Interpretation

The signals obtained with RFT are very similar to those obtained with conventional eddy current testing. When all the proper conditions are met, changes in the phase of the receiver signal with respect to the phase of the exciter voltage are directly proportional to the sum of the wall thickness within the inspection area. Localized changes in wall thickness result in phase and amplitude changes. These changes can be indicative of defects such as cracks, corrosion pitting or corrosion/erosion thinning.