DEVICE FOR THE CONTACTLESS INSPECTION OF UNDERGROUND PIPELINES

The proposed invention relates to devices for the contactless external inspection of the technical state of underground ferromagnetic oil and gas pipes. The invention is particularly effective in the inspection of small and medium diameter (100-500 mm) field pipes and transportation pipes, and also in flaw detection in steel and cast iron structures. The technical result of the proposed invention is that of increasing the functional capabilities and improving the performance of a device for the contactless inspection of the technical state of underground pipelines. This technical result is achieved in that the present device for the contactless inspection of the technical state of underground pipelines, which comprises an assembly of permanent magnetic field sensors, consisting of at least two single-component sensors connected by attachments made of a non-magnetic non-conductive material, a device for adding and subtracting permanent magnetic field signals, a control and data collection unit, and a field computer, additionally comprises coils with solenoid windings that generate a calibrating low-frequency variable magnetic field, said coils being disposed in the centre portion of the attachments made of a non-magnetic non-conductive material, a unit of precision resistors, a generator, a synchronization and control unit, and a measuring unit. The coils with solenoid windings are connected by a double-twisted pair to the unit of precision resistors and the generator. Furthermore, the unit of precision resistors is connected to the control and data collection unit, which, in turn, is connected to the field computer. L'invention concerne les dispositifs pour le diagnostic sans contact et s'effectuant en dehors des tubes des pipelines ferromagnétiques souterrains tels que oléoducs ou gazoducs. L'invention est particulièrement efficace dans le diagnostic de pipelines d'extraction ou de transport de petit ou grand diamètre (100-500 mm) ainsi que la détection de défauts des structures métalliques en acier ou en fonte. Le résultat technique de l'invention consiste à élargir les fonctionnalités et à améliorer les caractéristiques du dispositif pour le diagnostic sans contact de l'état technique des pipelines souterrains. Le résultat technique est obtenu grâce au fait que le dispositif de diagnostic sans contact de l'état technique des pipelines souterrains comprenant une unité de capteurs de champ magnétique permanent qui comprend au moins deux capteurs à composa