Underground Ferromagnetic Pipeline Detection Using a Rotable Magnetic Sensor Array

To eliminate the risk of damage to buried pipelines during excavation, a survey in advance or on the spot is necessary. Here we propose a wireless rotable magnetic sensor array to detect underground ferromagnetic pipelines. It consists of several sensing nodes placed on a rail, which can rotate automatically or manually. We adopted rotating rather than translating the array since translation is difficult on uneven or muddy ground. Moreover, we could judge the existence and orientation of a pipeline by simply checking the periodic variation of measured data without resorting to complex inversion algorithms. Field experiments showed that the equipment could provide a decimeter-level locating accuracy for both the horizontal offset and buried depth, and a strike angle error of a few degrees, which meet general engineering application requirements.