What is one essential fact regarding the sensitivity of magnetic particle testing methods?

The continuous method is generally considered more sensitive in magnetic particle testing because it provides a constant magnetic field, which allows for better detection of surface and near-surface discontinuities. This method enhances the ability to attract magnetic particles to defects, making it easier to visualize flaws. The continuous application of magnetism creates a stable environment for the magnetic particles, ensuring they align more accurately to any indications of discontinuities.

In contrast, the residual method, while valuable in certain applications, does not always maintain the same level of induced magnetic field strength, which can result in reduced sensitivity when detecting smaller or more subtle defects. Additionally, while both methods have their merits, the continuous method's stability and consistent field strength contribute to its overall effectiveness in detecting cracks and other surface flaws.