Ensayos por líquidos penetrantes

NDT penetrant testing includes fluorescent dye penetrant, which is typically green and uses a white developer to draw the dye back to the surface from inside the discontinuities by 'wicking' or capillary action. The fluorescent penetrant is characterised by its ability to emit visible radiation when excited by UV-A light and may be used on a variety of materials. Fluorescent penetrant is typically more sensitive than visible dye and is ranked into 4 levels of sensitivity. It does, however, require special lighting conditions: NDT penetrant technicians must have UV-A lamps, blackout shades and power generators in the field. Fluorescent-dye testing is easily performed under laboratory conditions.

Visible dye penetrant is a method of NDT penetrant testing, which is typically red and uses a white developer to draw the dye back to the surface from inside the discontinuities by 'wicking' or capillary action. This is often referred to as the 'colour contrast' method. The colour contrast created in the dye penetration test is highly visible under natural light and may be used on a variety of materials. It is generally not as sensitive to very small discontinuities as the fluorescent penetrant testing method. However, it does not require special lighting conditions, therefore NDT technicians do not have to carry UV-A Lamps, blackout shades or power generators.