Low-power eddy current detection with 1-1 type magnetoelectric sensor for pipeline cracks monitoring

Abstract

Pipeline systems, such as oil and natural gas pipelines, which are normally buried underground or distributed under the sea, are susceptible to corrosion and pressure destruction, and hence timely and reliable nondestructive testing (NDT) is necessary. Conventional nondestructive testing methods are generally based on ultrasonic, eddy current and magnetic flux leakage mechanism. With respect to eddy current testing (ECT) technologies, the current challenge is to develop magnetic sensors with high detection ability, extremely low power consumption and compatible with Internet of Things (IoT). Giant resonant magnetoelectric (ME) coupling has been previously reported in our proposed 1-1 ME composites. Here, we further presented an investigation on the eddy current testing (ECT) using 1-1 type ME sensor. The proposed ECT probe was built by integrating a small exciting coil surrounding the ME sensor. Simulation results indicate ECT based on ME sensors is especially applicable for non-ferromagnetic and low-conductivity materials, e.g. steel. One-dimensionally distributed cracks with varying crack sizes in a steel pipeline was then experimentally identified and located using ECT method. More importantly, the power consumption of our proposed ECT probe is as low as 0.625 uW, which shows 2–3 orders of magnitude improvement compared with other probes based on e.g. magnetoresistive (MR) sensors. Our research here provides a fundamental insight into NDT using ME sensors as a ECT probe and represents a crucial step towards online low-power monitoring of pipeline cracks.