How should developing powder be applied during penetrant inspection?

During penetrant inspection, the developing powder is applied evenly to create a consistent layer across the surface being inspected. This uniform application is essential because it allows for an even reaction with the penetrant that may have seeped into any cracks or imperfections in the material. An even coat ensures that any indications (or defects) are more easily visible, leading to more accurate inspection results.

When the developer is applied evenly, it helps to pull the penetrant out of the defects to the surface, allowing for better contrast and visibility against the background surface. This not only aids in identifying cracks or flaws but also reduces the risk of missing smaller indications that might not be as apparent with uneven application. The goal of penetrant inspection is to discover surface-breaking defects effectively, and an even application of the developer is critical for achieving that objective.