Table from Hand book of nondestructive testing By Charles Hellier.
Technique I Fluorescent
Process A
Water Removable penetrant ; Dry, Aqueous, or nonaqueous developer.
Process B
Postemusifiable penetrant; Lipophilic emulsifier; Dry, aqueous, nonaqueous developer.
Process C
Solvent removable Penetrant; Solvent cleaner/remover ; Dry or nonaqueous developer.
Process D
Postemusifiable penetrant; Hydrophilic emulsifier; Dry, aqueous, nonaqueous developer.
Technique II Visible color contrast
Process A
Water removable penetrant ; aqueous, nonaqueous developer.
Process B
Postemusifiable penetrant, Emulsifier, and aqueous, or nonaqueous developer.
Process c
Solvent removable penetrant; Solvent cleaner/remover aqueous, or nonaqueous developer
From Hand book of nondestructive testing By Charles Hellier. Dry developers are not usually used with Technique II Penetrants. Some specs will not allow the use dry developers with Technique II Penetrants.
From Liquid Penetrant Testing Training Book (Hellier). Dry Developer is the least sensitive and should not be used for visible Penetrants.
mike k