Shield excitation quantitative determination probe and method thereof

Abstract

The invention relates to an excitation-shielding quantitative detection probe and a corresponding method. The probe comprises a rectangle constant permanent magnet, an L-shaped shielding element and a magneto sensor. The L-shaped shielding element is attached to an S-pole part of a horizontal side-face and a non-working-face of the rectangle constant permanent magnet; the magneto sensor is arranged on a magnetic-field zero-intensity position of a mutual zone between the N-pole and S-pole on the non-working-face of the rectangle constant permanent magnet. The method includes the following steps: a magnetic field intensity initial value of a magnetometer is set; the working face of the probe is led to touch an outer wall of a detected austenitic steel pipe and to move along the length of the steel pipe; both a position on the steel pipe where the detected magnetic field intensity is the maximum and a position on the steel pipe where the detected magnetic field intensity is reduced to aninitial value from the maximum are recorded; the probe is moved along the circle of the steel pipe and a position on the steel pipe where the magnetic field intensity is reduced to the initial value is recorded. For the invention, the size of the probe is small so as to reduce the interference to the detection by the accumulated oxide film in the austenitic steel pipe. The invention can be widelyapplied to the detection to boilers of power plants.

Description

technical field [0001] The invention relates to detection technology, in particular to a shielded excitation quantitative detection probe and method. Background technique [0002] After a period of operation of the high-parameter power plant boiler, the high-temperature steam flowing in the austenitic steel pipe in the boiler will undergo an oxidation reaction with the tube wall metal to generate oxides (the main component of the oxide is ferric oxide), and these oxides adhere to On the inner wall of the tube, an oxide scale is formed. As the operating time of the boiler increases, the scale attached to the tube wall gradually thickens. During the start-up and shutdown of the boiler, due to the relatively large temperature difference between the cold and hot tube walls, and the large differences in expansion coefficient and contraction coefficient between the tube wall and the oxide scale attached to it, the bonding force between the oxide scale and the tube wall is also re...

AI Technical Summary

Problems solved by technology

[0008] It can be seen that in the prior art, due to the relatively large size of the probe in the detection device and the relatively small spacing between the boiler tube bundles, the detection signal is relatively stray and the reliability is poor

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