为了更好地进行现场检测及缺陷定量分析，并探究缺陷类型及深度对漏磁场信号的影响，根据标准NB/T 47013.12-2015制备管件校准试件、对比试件和裂纹试件。利用可变径管道外壁的漏磁检测仪器对存在点蚀、裂纹等缺陷的38.1，50.8，76.2，101.6 mm共4种管径的试件进行漏磁检测。结果表明，管外壁缺陷漏磁场信号强于内壁缺陷信号，内外壁漏磁场信号均随缺陷深度的增加而增强，槽形缺陷的漏磁场信号强于球形缺陷的漏磁场信号。

In order to better undertake field detection and quantitative analysis of defects, it is urgent to explore the effect of the type and depth of defects on the leakage magnetic field signal. According to the standard of NB/T 47013.12-2015, the pipeline calibration specimen and the contrast specimen and the crack specimen were prepared. The diameter-variable magnetic flux leakage testing device outside pipeline was carried out on the pipe diameter of 38.1, 50.8,76.2,101.6 mm, which were small defects such as pitting and crack. The experimental results show that the leakage magnetic field signal of the outer wall defect is stronger than that of the inner wall; the leakage magnetic field signal of the inner and outer wall is enhanced with the increase of the defect depth; the leakage magnetic field signal of the groove defect is stronger than that of the spherical defect.