提出了一种铁磁性发动机壳体内叶片动态原位监测方法，该方法利用涡流检测方法监测铁磁性发动机叶片的个数、转速、损伤状态等。将两个磁极固定于铁磁性发动机壳体外表面，将涡流检测探头固定在磁极之间，叶片转动过程中，叶片的尖部划过表面附近涡流场，探头感生涡流信号传输至涡流检测仪。通过每分钟的涡流信号个数计算叶片转速；通过涡流检测信号的幅值，测算叶片与壳体内表面的间隙；通过信号幅值的不同，判断出叶尖表面的缺损；通过间隔时间出现不均匀的涡流信号，判断叶片弯曲或断裂。该方法可以解决铁磁性发动机壳体内叶片的安全监测难题。

In this paper, a method of dynamic monitoring of the blades in the inner shell of ferromagnetic engine is presented, and the number, rotating speed and damage state of blades in ferromagnetic engine are monitored by eddy current testing method. Two magnetic poles are set on the surface of ferromagnetic casing, and the eddy current testing probe is fixed between the poles. Blades rotate though the eddy current field near the surface, and eddy current signal is induced in the probe and is transferred to the eddy current instrument. The rotor speed can be calculated by the number of eddy current signals per minute. By measuring the amplitude of eddy current detecting signal, the clearance between the blade and the inner surface of the shell can be calculated. The defect of tip surface can be determined by different signal amplitude. Whether the blades bend or break can be determined when the eddy signal is not evenly spaced. The method can solve the problem of blade safety monitoring in the ferromagnetic engine casing.