Buried Metal Pipeline Detection Based on Passive Micro Magnetic Technology

In the field of the buried metal pipeline detection, most of the conventional detection is a contact.It is necessary to excavate and stop running before detection. So it is difficult to meet the requirements of industrial detection. Passive micro magnetic detection technology can realize the buried pipeline trenchless detection. In the basis of the principle of the detecting technology, the distance between the magnetic sensor measurement and pipes is to simulate the actual depth of the pipe. It is found that the relationship between change of the magnetic intensity,the depth of pipeline,and corrosion depth which through the pipe after a lot of date of experiment are analyzed. On the basis of this,combination of gradient magnetic field and the principle of probability and statistics can draw defect judgment basis,that is when the magnetic field gradient in the interval (μ-2σ,μ+2σ) to change the defects can be judged.The conclusion shows, compared with conventional detection methods, the passive micro magnetic technique doesn't have to artificial magnetize the pipe in advance, which guarantees of buried metal pipeline corrosion condition of scientific assessment and realize the detection of 2D imaging in the condition of non-excavation.