What is dry developer, and when is it typically used?

Dry developer is a powder form that is specifically designed to absorb excess penetrant from the surface of a part being inspected. Once the penetrant has been applied and allowed to dwell, the purpose of dry developer comes into play. It is typically used in situations where rapid processing is advantageous, such as in inspecting parts that require a quick turnaround or where the parts cannot be saturated in liquid developers.

The advantage of using a dry developer lies in its ability to quickly draw out the liquid penetrant from discontinuities, effectively highlighting them against the surface of the material. This not only makes the defects more visible but also reduces the amount of time required for the inspection process.

In contrast, other forms of developers, such as liquid or gel developers, may require longer dwell times or specific application techniques that can slow down the inspection process. The selection of dry developer often hinges on the need for efficient and effective testing, allowing for faster analysis while still maintaining the quality of results.