METHOD AND DEVICE FOR CONTACTLESS DIAGNOSTICS OF TECHNICAL CONDITION OF UNDERGROUND PIPELINES Russian patent published in 2015 - IPC F17D5/02 

FIELD: measurement equipment.

SUBSTANCE: method includes measurement of components of permanent magnetic field above a pipeline during movement of sensors of permanent magnetic field along a pipeline, compensation of impact at results of measurement of Earth permanent magnetic field and mathematical processing of measurement on the basis of a gradient matrix made of sums and differences of components. At the same time they use at least 7 three-component sensors of permanent magnetic field with central symmetry and location of one sensor in the centre of symmetry. Sums and differences of same-name components of permanent magnetic field are determined on the basis of components measured by sensors arranged in extreme points from the centre of symmetry, and differences of same-name components measured by the sensor installed in the centre of symmetry and sensors located in extreme points from the centre of symmetry along each of three orthogonal axes of coordinates. After determination of components of permanent magnetic field they use tensor processing of gradient matrices with computation of the matrix of the first derivatives of magnetic induction and matrix of the second derivatives of magnetic induction, at the same time they compare parameters of second derivative signals of magnetic fields of noises, magnetic field of the pipe and magnetic fields of defects, and compute geometric characteristics of abnormality-forming objects in the pipeline.

EFFECT: increased accuracy and sensitivity of the method and device for diagnostics of technical condition of steel gas and oil pipelines.

6 cl, 3 dwg