FIELD: diagnosis of the state of materials and structures mainly of ferromagnetic materials. SUBSTANCE: device has interconnected one conveying measuring module and service modules. The measuring module is intended for measuring the intensity of natural magnetic fields set up in the pipe metal by clusters of dislocations and twins, nuclei of defects. The measuring module comprises transmitter units of normal and tangential components of magnetic field intensity, multi-channel converter of input signals, multi-channel meter of magnetic permeability of the pipe metal. Each transmitter unit has two measuring transmitters of tangential component of magnetic field intensity and a measuring transmitter of normal component. The device may be provided with a module of ultrasonic diagnosis. EFFECT: provision of quantitative information on the degree of danger or activity of incipient and propagating cracks. 6 cl, 7 dwg
