Document ID: chunk:federal_register_of_legislation:F2007L04654:body:0:p5
Version: federal_register_of_legislation:F2007L04654
Segment Type: other
Provision Reference: 
Character Range: 10786–13699

minimum time required for a given part at a given temperature to achieve an acceptable "background" allowing indications to be clearly visible after development. After emulsification, parts must be washed with water as described in paragraph 3.2.

4 Application of developer

       4.1Liquid suspended developers must be applied by spray or dip. Dry developer powders may be applied by any method which ensures that the powder remains in stationary intimate contact with the surface of the part during the development time, after which, excess powder must be shaken from the part or removed by gentle blowing or tapping.

       4.2Dry developer powders must be used only in conjunction with fluorescent penetrants.

       4.3Parts must be thoroughly dried after water washing and before the application of solvent suspended or dry developer after application of water suspended or water soluble developer powders. Drying may be facilitated by using warm air at a temperature not exceeding 80C provided that the temperature of the surface of the part is not raised above 50C.

5 Inspection

       5.1Following application of solvent suspended or dry developer powders or, in the case of water suspended or water soluble developers, after drying is complete, a period of 10 minutes or half the penetration time, whichever is the greater, must elapse before final inspection of the part.

       5.2When colour contrast dye penetrants have been used, inspection must be effected under good conditions of white light illumination providing an intensity at the surface under inspection of not less than 1080 lumen m­² or 100 foot candle when measured with a Weston Light Meter Model 703 type 51 or equivalent.

       5.3When fluorescent dye penetrants have been used, parts must be inspected with ultraviolet light under conditions of darkness or near-darkness. Inspection lamps must contain a filter to minimise the intensity of visible light transmitted and to eliminate harmful ultraviolet light of wave length less than 3,000A while permitting maximum transmission of ultraviolet light of approximately 3650A. The intensity of ultraviolet light at the surface to be inspected must be not less than 970 lumen m­² (735 Wcm­² or 90 foot candles) when measured with the instruments described in paragraph 3.1 of Appendix III to this Order.

6 Cleaning of parts after penetrant inspection

       All traces of penetrant materials should be removed from parts within 4 hours after the application of developer. Final cleaning must be particularly expedited in the case of magnesium alloys which are very susceptible to corrosion in the presence of developer powders.

7 Repeat inspections

       7.1If it is necessary to undertake a repeat inspection of a part, the same process and materials from the same source of manufacture as used in the initial inspection must be used unless it has been established