| 摘要 |
<p>In a method for the non-destructive test of surface defects, there is applied to the surface a solution with one or a plurality of dyes which do not emit any radiation under the effect of ultra-violet light. The solution in excess after penetration of the latter into the surface defects is wiped away and the surface is covered with a day light-sensitive developer layer which contains from 0.02 to 2.0% by weight of one or a plurality of clearing agents. The coating layer absorbs the colour remaining in the surface defects which appear as black traces under the effect of ultra-violet light.</p> |
