Magnetic flux leakage detection refers to the formation of magnetic leakage field on the surface of ferromagnetic material due to the defects on the surface or near the surface of the specimen after magnetization. People can detect the defects by detecting the changes of magnetic leakage field. The so-called leakage magnetic field is that when the material has the defect of cutting magnetic force line, the surface defect or the change of the structure state of the material will change the permeability.

According to the China Petroleum and Natural Gas Pipeline Administration (CPP), a national scientific research project undertaken by the pipeline administration and a key international cooperation project of CNPC in the 11th Five-Year Plan, a 1016mm diameter high-definition pipeline magnetic flux leakage detector, was recently launched in Beijing. This is the first set of high-definition pipeline magnetic flux leakage detector in China, which fills the gap in the field of high-definition pipeline detection technology in China.