Low-frequency electromagnetism-based defect detecting device

Abstract

A low-frequency electromagnetism-based defect detecting device is characterized by consisting of a signal generator (1), a power amplifier (2), a exciting coil (3), a Hall element (4), an oscilloscope (5) and a support (6); the signal generator (1) produces a low-frequency sinusoidal signal of 1 to 100Hz, the low-frequency sinusoidal signal is amplified by the power amplifier (2), then the signal passes through the exciting coil (3) placed on the support (6) to produce a magnetic field, a defect makes the magnetic field change, and the Hall element (4) can sense the change of the magnetic field and display the change through the oscilloscope (5). According to the defect detecting device provided by the invention, a low-frequency signal is taken as an excitation signal, so the detection depth is improved without permanent magnet excitation and coupling, the cost is relatively low and the defect detecting device can be applied to various practical engineering.

Description

technical field [0001] The invention relates to a defect detection device based on low-frequency electromagnetic, which belongs to the detection of metal defects. Background technique [0002] Ferromagnetic metal materials are widely used as stress-bearing structural parts of pressure-bearing equipment. During use, early damage caused by stress concentration and corrosion of metal materials are the main safety hazards of pressure-bearing special equipment, so rapid detection and early diagnosis are of great importance. For the detection of defects such as corrosion, the existing non-destructive testing methods such as ray, ultrasonic, magnetic particle and infiltration have their own shortcomings in adapting to the high and low temperature environment of the site and the surface condition of the equipment. Coupling, so that ultrasonic waves can be transmitted and received between the sensor and the metal body. ②It is generally aimed at the measurement of the wall thickness...

AI Technical Summary

Problems solved by technology

For the detection of defects such as corrosion, the existing non-destructive testing methods such as ray, ultrasonic, magnetic particle and infiltration have their own shortcomings in adapting to the high and low temperature environment of the site and the surface condition of the equipment. Coupling, so that ultrasonic waves can be transmitted and received between the sensor and the metal body

②It is generally aimed at the measurement of the wall thickness at a certain point, and is not suitable for large-area scanning detection, so the detection speed is very slow

However, there is currently a lack of systematic research on the application of low-frequency electromagnetic methods in the detection of pressure equipment, so they cannot be widely used.

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