Hydrogen is evolved during metal electrodeposition in aqueous baths. Some of this hydrogen enters parts during plating. If the absorbed hydrogen is at a level presenting embrittlement hazards to high-strength steel, it is removed by baking parts after plating to expel this hydrogen. However, the lack of plate porosity itself may block hydrogen egress. Thus, it becomes important to know both the relative amount of hydrogen absorbed and the plate porosity.

This test provides a quantitative control number for cadmium plate porosity that can be used to control a cadmium plating process and the status of cadmium-plated hardware. It can also be used for plating process troubleshooting and research and development to determine the effects on plate porosity by process variables, contaminants, and materials. When used to control a critical process, control numbers for plate porosity must be determined by correlation with stress rupture specimens or other acceptable standards.

There is no prime standard for plate porosity. For this reason, two ovens must be used, with tests alternated between ovens. Data from the ovens are compared to ensure no equipment change has occurred.