Figure 1-8. Specific Gravity Hydrometer Readings versus Concentration for One Manufacturers Water Soluble
Fluorescent penetrant dye contamination can be checked by visual examination of the bath surface with a black light.
Testing Dry Developer.
Dry developers, unlike water based developers, do not have a problem with concentration changes. However, dry
developers do become contaminated. Water or moisture from inadequately dried parts splashed into tanks by careless
rinsing or condensation are potential sources of contamination. Dry developers can also become contaminated with
penetrant when lumps of penetrant-soaked developer from heavy indications or improperly rinsed parts fall off during
Dry developers SHALL be periodically checked for evidence of contamination. Visually examine while stirring or
mixing the dry powder. Check for evidence of clumps. It may be possible to dry the powder if the water content is low.
The lumps of developer must be removed or crushed into loose flakes. If it is not possible to restore the original
consistency, the developer SHALL be discarded. The test for penetrant is an examination under black light while
stirring or mixing the dry powder. Penetrant contaminated dry developer SHALL be discarded.