Development of Permanently Installed Magnetic Eddy Current Sensor for Corrosion Monitoring of Ferromagnetic Pipelines

Abstract

Permanently installed sensors are a cost-effective solution for corrosion monitoring due to their advantages, such as less human interference and continuous data acquisition. Some of the most widely used permanently installed corrosion sensors are ultrasonic thickness (UT) gauges. However, UT sensors are limited by the need for coupling agents between pipe surfaces and sensors. The magnetic eddy current (MEC) method, on the other hand, does not require couplant and can be used over insulations. With the development of powerful rare earth magnets, MEC sensors with low power consumption are possible, and there is the prospect of using them as permanently installed sensors. A novel wireless magnetic eddy current sensor has been designed and optimized using finite element simulation. Sensitivity studies of the sensors reveal that the excitation frequency is a critical parameter for the detection of corrosion defects. An in-depth explanation of the relationship between the sensitivity of the sensor and the excitation frequency is presented in this paper. The results of an accelerated corrosion test, conducted to simulate the service environment of the sensor, are also discussed. It was observed that the sensor signals are very sensitive to corrosion defects and show no subtle differences due to temperature and humidity changes.

Reliability Improvement of Magnetic Corrosion Monitor for Long-Term Applications

“…The details on the optimisation of the design of the MEC sensor system and dimensions are discussed in [ 57 , 60 ].…”

“…The above discussion reveals that there is very limited work carried out on the development and reliability evaluation of electromagnetic corrosion monitoring devices for both internal and external corrosion. This paper presents the work carried out on the improvement and evaluation of long-term reliability of magnetic corrosion monitor discussed in [ 57 ]. The research has the following contributions: Design of a novel smart corrosion monitor based on a dissimilar active redundancy approach to monitor wall loss due to internal and buried corrosion at critical locations; Development of methodology based on Pearson’s correlation coefficient for diagnosis of faulty sensors from time series data; Evaluation of stability and performance of the novel magnetic monitor for an extended time period through real life aging tests conducted for seven months.…”

Review of corrosion monitoring and prognostics in offshore wind turbine structures: Current status and feasible approaches

“…The results show that the mass loss in reinforced steel due to corrosion and the voltage increment of the hall effect sensor are linear and therefore it is concluded that the proposed magnetic corrosion device is capable of quantitative analysis of corrosion rate. In Wasif et al (2022), authors propose magnetic eddy current based sensor for corrosion monitoring of pipelines. The sensor design optimization, sensitivity and power consumption have been studied.…”

Model of an E-cored probe over layered conductor containing corrosion for eddy current testing

“…However, corrosion is not easily found by visual inspection. Therefore, how to detect and evaluate corrosion noninvasively in the early stage is a key issue to ensure the normal operation of equipment and avoid economic, environmental and human losses (Wasif et al , 2022).…”