T.O. 33B-1-1 2-10 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. NOTE Form designations reflect ASM 2644, which has superseded MIL-25135.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. Type Type I Fluorescent Dye Type II Visible Dye Type III Dual Mode (Visible and Fluorescent Dye) Method Method A Water Washable Method B Postemulsifiable, Lipophilic Method C Solvent Removable Method D Postemulsifiable, Hydrophilic Sensitivity Level Level ½ Very Low Level 1 Low Level 2 Medium Level 3 High Level 4 Ultra High Developer Form a Dry Powder Form b Water Soluble Form c Water Suspendible * Form d Nonaqueous (Wet; for Type I) * Form e Nonaqueous (Wet; for Type II) * Form f Specific Application Solvent Remover Class 1 Halogenated Class 2 Nonhalogenated Class 3 Specific Application 2.2.5.2 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