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April 2013 - The penetrants’ fluorescence (follow-up)

Written by Administrator
Friday, 15 March 2013 16:46

In one of our previous papers(1), we dealt with the penetrants’ fluorescence and the involved mechanisms. The fluorescence optimization is achieved, thanks to the right choice of dyes based on:
• Their respective excitation and emission spectra,
• Their combination to get the best excitation energy transfer (usually called “cascading effect”, a term to be avoided) from the donor D to the acceptor A.

This new article deals with a topic, the importance of which is paramount because it affects the reliability of fluorescent penetrant inspection.
It is about factors affecting the penetrants’ fluorescence.

Richard Lopez, a co-author of this paper, provides us with his expertise in this field, supported by the results of a certain number of his works.

We thank Bernard Value for giving us a glimpse of the complexity of the theory (or theories) on the molecular fluorescence. However, we stayed with the essential elements only, as too a theoretical development would have driven us too far.

We chose to focus more on practical aspects.
Indeed, this is the way of working we have chosen, as PT and MT specialists, to write all our papers. Our aim is to provide guidance to both users (the parts preparation, the lack of residue, the unnecessary exposure of parts to UV, etc.) and manufacturers on how products should be designed in the laboratory to be used in the workshop or on site. We always have in mind some drawbacks due to products designed and marketed without ensuring beforehand that they really comply with the industrial needs of users.

Finally, let us remind you that PT and MT rely on phenomena that occur at the electrons’ level.
Therefore, these methods have nothing to envy to "electronic" techniques that some people are trying to impose to replace them, while the two methods have the advantage that they may be used almost anywhere (except underwater for PT), regardless of the parts, whatever their
shape, size, location, accessibility, with rare exceptions, using light sources (white, blue or UV-A, as required), and, same-old story, outstanding detectors linked to a 3D information-processing system, in real time, able to take fully autonomous decisions and initiatives: the inspector’s eyes and brain.


(1) Pierre CHEMIN and Patrick DUBOSC, Dyes and fluorescent penetrants, August 2012: on
our Website

Last Updated ( Saturday, 16 March 2013 09:34 )