What is true regarding the reliability of the liquid penetrant method compared to radiographic testing?

The liquid penetrant method is particularly well-suited for detecting minute surface discontinuities, which are often difficult to find using other non-destructive testing techniques. This method involves applying a liquid penetrant to the surface of the material, which seeps into any surface-breaking flaws. After a period allowing the penetrant to dwell, excess material is removed, and a developer is applied, enhancing the visual indications of these defects. This process is effective for identifying very small cracks or porosities that can be critical in many applications, especially in welds or on machined surfaces.

In comparison, radiographic testing primarily focuses on volumetric discontinuities, such as internal flaws within a material. While it can provide a broader view of potential issues, it may not always detect surface defects as effectively as liquid penetrant testing can.

The options regarding effectiveness for larger discontinuities and equality in effectiveness for all types of discontinuities do not accurately represent the capabilities of these methods, as liquid penetrant testing is specifically designed for surface-level flaws. Additionally, while both methods require training, liquid penetrant testing generally requires less specialized knowledge than radiographic testing, particularly regarding handling and interpreting complex radiographs.

Thus, stating that the liquid penetrant method is more reliable for detecting