The device of a magnetic flaw detector and a method of reducing the error in determining the size of pipeline defects by magnetic flaw detectors

摘要

1. The device of the magnetic flaw detector contains a system of magnetic field sensors with a block of amplification of the signals of the magnetic field sensors, an analog subtraction unit and an excitation generator of magnetic field sensors, characterized in that a special sensor is used, which consists of a magnetic plate installed in close proximity to the inner wall of the pipeline , and at an equal distance from which two semiconductor magnetic converters are installed on both sides, while the signal of a special sensor is approximately rtsionalen differential relative permittivity of the tube material at the magnetizing field with respect to the direction of rolling lista.2. The magnetic flaw detector device according to claim 1, characterized in that the special sensor is included in the sensor block mounted on a board on which magnetic field transducers are installed that measure the magnetic field of the defect, while the magnetic field transducers are installed at such a distance from the magnetic plate of the special sensor, so that the field from it does not affect the measurement of the fields of defects, while the sensor block is flooded with a compound and placed on a wear-resistant substrate that slides along the inner wall of the pipeline. 3. The magnetic flaw detector device according to claim 2, characterized in that several channels for measuring the magnetic field of the defect are located on one sensor unit. A way to reduce the error in determining the size of pipeline defects by magnetic flaw detectors is that the magnetic flaw detector is calibrated by passing over a section of the pipeline with pipes of various thicknesses: minimum, average and maximum, made