What is a typical application of liquid penetrant testing?

Liquid penetrant testing is specifically designed to identify surface defects in non-porous materials. This method exploits the ability of liquid penetrants to seep into any flaws, such as cracks or voids, that are open to the surface. When the excess penetrant is removed and a developer is applied, it draws out the penetrant trapped in the defects, making them visible under ultraviolet or white light.

While welding inspection, concrete testing, and weld joint evaluations might use various non-destructive testing methods, such as radiographic or ultrasonic testing, these methods typically assess different aspects. Welding inspection and weld joint evaluation can involve assessing internal defects, which may not be visible at the surface, and concrete testing is generally not compatible with penetrant methods due to the porous nature of concrete. Therefore, surface defect detection is the most fitting application for liquid penetrant testing.