Magnetic Permeability Perturbation-Based RFID Sensor for Pipeline Internal Corrosion Monitoring

Radio frequency identification (RFID) sensors for pipeline corrosion monitoring have been considered an attractive area due to the advantages of battery-free and maintenance-free. Due to the skin effect of high-frequency electromagnetic waves, existing RFID sensors can only detect the surface corrosion of pipelines. To realize internal corrosion monitoring, a magnetic permeability perturbation-based RFID sensing method was developed in this article. Under direct-current magnetization, internal corrosion causes magnetic field distortions, and incurs magnetic permeability perturbations in the skin layer of surface. These perturbations can be detected by the RFID sensor. Considering the resonance frequency shift (RFS) as a feature, a patch antenna sensitive to magnetic permeability was designed. Moreover, steel plates with artificial internal defects were simulated and tested to validate the feasibility of the proposed method. It was observed that the surface magnetic permeability perturbations caused by internal corrosions of different depths incur different RFS values. Finally, pipelines with artificial and natural internal corrosions were tested to validate the feasibility of the proposed method. The RFS caused by the natural corrosion was 4.26 MHz, and the RFS caused by the sound area was 1.63 MHz. The proposed magnetic permeability perturbation-based RFID method provides a promising method for pipeline internal corrosion monitoring with the application of RFID sensing technology.