Which method is generally more sensitive in magnetic particle testing?

The continuous method in magnetic particle testing is generally considered more sensitive due to its ability to detect smaller flaws and discontinuities in the material. This method involves the continuous application of magnetic flux, which provides a more thorough and uniform field for the detection of surface and near-surface defects. When using the continuous method, the magnetic particles are attracted to the leakage fields created at defects, allowing for better visibility of the indications.

The continuous method can offer real-time observations, making it easier to identify and assess discontinuities as they form, which enhances the overall effectiveness of the inspection. This method is particularly useful in critical inspections where the detection of minute cracks or irregularities is essential to ensure the structural integrity of the component being tested.

In contrast, the residual method, while useful in certain applications, typically does not provide the same level of sensitivity because it relies on the residual magnetic field remaining after the magnetic particle has been applied and removed. Other methods such as the wet method and solid method have specific applications but may not achieve the same sensitivity as the continuous method in detecting small defects.