D-72A Developer is used with fluorescent penetrants as form “a”. It is applied after the surface penetrant has been removed and the inspection surface dried. D-72A dry powder developer consists of light fluffy absorbent powder. The particles are very light and will float in the air and are considered a nuisance dust This form of developer is generally applied in special storm or dust chamber equipment, but may also be dusted on to parts with a feather duster, or electrostatic spray. If sprayed avoid build up of a heavy developer film. A very fine dusting is the recommended coverage. The developer film is easily removed from the part surface with water after inspection.