What aspect of continuous magnetization affects the effectiveness of magnetic particle testing?

In magnetic particle testing, the effectiveness of the process is significantly influenced by the type of current used for magnetization. When applying magnetic fields to an object, alternating current (AC) and direct current (DC) have different effects on the particles and the magnetic field distribution within the test subject.

AC provides a more uniform magnetic field and is particularly effective in detecting surface flaws, as it can induce the magnetic particles to form indications on the surface more readily. On the other hand, DC creates a stronger and more concentrated magnetic field, which is effective for identifying subsurface defects. The choice between AC and DC can significantly impact the ability to detect flaws depending on their location and the material being tested.

Thus, understanding the implications of the type of current on magnetization helps ensure the effectiveness of the magnetic particle testing and enhances the likelihood of correctly identifying defects.