Fundamental Knowledge of Magnetic Flux Leakage Testing Equipment

Electromagnetic testing is a very important non-destructive testing method and is widely used. Magnetic flux leakage testing equipment plays an essential role in the testing process. Magnetic flux leakage testing is a magnetic non-destructive testing method used to detect corrosion and pitting in steel structures, most commonly in pipelines and storage tanks. In order to better utilize the magnetic flux leakage testing equipment, we first need to understand some basic knowledge about it. Only by mastering this basic knowledge can we fully leverage the advantages of the magnetic flux leakage testing equipment and ensure the accuracy and reliability of the test results.

What Is a Magnetic Flux Leakage Field?

When a magnetizer acts on the ferromagnetic material being tested, if the material is continuous and homogeneous, the magnetic induction lines will remain tightly within the material. The magnetic flux flows parallel along the surface of the material with very little magnetic induction lines escaping to the surface. Therefore, the surface of the workpiece being tested almost does not show a magnetic field.

However, once there are defects in the material that can cut the magnetic field lines, these defects or changes in the internal organizational state of the material will cause significant changes in magnetic permeability. Due to the lower magnetic permeability at the defect, the magnetic reluctance increases significantly, leading to distortion in the distribution of the magnetic flux in the magnetic circuit. The magnetic induction lines that originally flowed within the material will change direction when approaching the defect. Apart from some magnetic flux that directly crosses the defect or bypasses it within the material, some magnetic flux will leak out to the surface of the material, bypass the defect through the air, and then re-enter the material. This forms a visible magnetic flux leakage field at the defect on the material's surface.

What Is Magnetic Flux Leakage Testing?

Magnetic flux leakage testing refers to the detection method where ferromagnetic materials are magnetized, and due to defects on the surface or near the surface of the specimen, a magnetic flux leakage field forms on its surface. By detecting changes in the magnetic flux leakage field, defects can be identified.

What Are the Characteristics of Using Magnetic Flux Leakage Testing Equipment?

Thanks to its magnetic sensor technology, magnetic flux leakage testing equipment shows significant advantages compared to traditional magnetic particle and penetrant testing methods:

Highly automated: magnetic flux leakage testing equipment is easy to automate, greatly improving testing efficiency.
High reliability: Using computer analysis of the detected signals, it can accurately determine the presence of defects, effectively eliminating potential errors from human factors that might be present in magnetic particle and penetrant testing methods, ensuring the reliability of the detection.
Preliminary quantification of defects: This technology not only detects defects but also provides a preliminary quantification of them, offering more precise data support for subsequent repair and maintenance.
Simultaneous detection of the inner and outer walls: In pipeline testing, for pipes with a thickness of up to 30mm, magnetic flux leakage detection equipment can detect defects in both the inner and outer walls simultaneously, achieving comprehensive coverage.
Efficient and pollution-free: Automated and efficient detection processes not only enhance work efficiency but also ensure a pollution-free detection process, meeting modern industrial environmental protection requirements.

In complex and variable industrial environments, minute magnetic flux leakage phenomena may conceal significant safety hazards. BKN magnetic flux leakage testing equipment, with its exceptional precision, can quickly capture the slightest changes in the magnetic field, making magnetic flux leakage issues hard to hide. We adopt international leading magnetic flux leakage detection technology, combined with precise sensors and high-speed processing chips, to ensure stable operation of the equipment in complex environments, providing robust safety assurance for your industrial production. In industrial production, safety always comes first. Choosing BKN magnetic flux leakage testing equipment is choosing safety and trust. We are committed to providing the most reliable protection for your industrial production, making your production safer and more efficient.