With the penetrant testing procedure you can quickly determine surface discontinuities on all iron metals and non-iron metals, some plastics and ceramic materials, glass, etc., provided that the discontinuities are open to the surfaces.

This procedure is used in the examination of welding seams, cast pieces, in shipbuilding, automobile and aircraft construction, apparatus and tank construction, etc. Liquid penetrant testing can be carried out with at daylight visible and/or under UV-light fluorescent penetrants.
This method is charactestic for the fact that, contrary to the magnetic particle inspection, defects or discontinuities can be proven also on not magnetizable materials.