Liquid Penetrant Testing Level 3 (PT-3) Practice Exam

Liquid Penetrant Testing (PT) is a non-destructive testing method primarily used to detect surface-breaking defects on various materials, particularly metals. It operates on the principle of capillary action, where a liquid penetrant is absorbed into surface flaws.

Surface-breaking cracks, laps, seams, and porosity are all surface-related defects, meaning that the penetrant can easily seep into these irregularities, making them visible upon the application of a developer and inspection.

In contrast, internal voids are not typically detected using this method as they do not reach the surface. Liquid penetrant testing is designed to identify flaws that are accessible from the surface, and internal defects would remain hidden from the penetrant. Therefore, the detection capabilities of this technique are limited to surface discontinuities, making internal voids the correct answer for the type of defect not typically detected by Liquid Penetrant Testing.