A Noise Suppression Method for Pipelines EMAT Signals Using a Pseudo Random Code

The electromagnetic transducer (EMAT) guided wave technology is an effective method for the long-range, non-contact rapid inspection of pipe. Since the EMAT signals for pipelines inspection are very weak and have a lot of noise components, the disadvantages of the general amplifying and filtering methods for noise suppression are analyzed, and a noise suppression method using data superposition for pipelines EMAT signals is presented. And the method is improved by using a pseudo random code to control the sending out time of the excitation. The experimental results demonstrated that the method was effective and reliable to suppress the noise in the EMAT signals for the pipeline inspection, and also had a good adaptability to different surroundings.