a. Type of penetrant (fluorescent or visible dye).
b. Method of removing excess surface penetrant.
c. Sensitivity Level of a penetrant system.
d. Form of developer.
e. Class of solvent remover.
Form designations reflect ASM 2644, which has superseded MIL-25135. ASTM E
1417-95a did not reflect this change at the time of publication. The Specific
Application categories in Table 2-1 for nonaqueous developers and solvent
removers allow a manufacturer the opportunity to optimize the formulation of these
products for one of their own specific penetrant systems or for a specific user need.
Table 2-1. Classification of Penetrant Materials Contained in ASM 2644.
Dual Mode (Visible and Fluorescent Dye)
* Form d
Nonaqueous (Wet; for Type I)
* Form e
Nonaqueous (Wet; for Type II)
* Form f
Classifications in Other Documents.
The ASM 2644 classifications are referenced in process standard ASTM E 1417 (latest version), the American Society
for Testing and Materials (ASTM) Practice for Liquid Penetrant Examination. The Type and Method classifications