Magnetic particles may be applied as a dry powder, or wet, by using either water or a high flash point petroleum distillate as a liquid vehicle carrier. Dry powder is available in various colors, so the user can select the color that contrasts best with the color of the surface upon which it is used. Colors for use with ordinary visible light are red, grey, black, or yellow. Fluorescent particles are widely used in wet baths, since the bright fluorescent indications produced at discontinuities are readily seen against the dark backgrounds that exist in black light inspection areas. Radiographic Inspection Radiographic is a nondestructive inspection method that uses a source of X-rays to detect discontinuities in materials and assembly components.
Radiation is projected through the item to be tested, and the results are captured on film.
Radiography is one of the most expensive and least sensitive methods for crack detection. It should only be used to detect flaws that are not accessible or favorabl y oriented for use by other test methods. The composition of the material. is dependent 2. The product of the density and the thickness of the material. The energy of the X-rays, which is incident upon the material.