Signal processing and imaging of pulsed eddy current testing for corrosion of water wall tubes

In order to realize the visualization of pulsed eddy current testing of water walls, a high sensitivity imaging method was proposed from three aspects of signal filtering, signal feature extraction and imaging. Through quantitative comparison of the signal to noise ratio of different filtering methods, it shows that the proposed filtering method has a significant effect in the signal processing of pulsed eddy current testing. The slope feature is extracted by differential method for imaging. The image thickness is characterized with high accuracy and can be imaged in real time, which is helpful for field personnel to find defects in time.