The excitation or lack of excitation of these dials by UV is not related to tritium; it's the response of the particular phosphor formulation to UV or visible light excitation.
Tritium was the power source originally intended to excite the phosphor. Tritiated polymer binder was formulated with phosphor particles (e.g. zinc sulfide) and other minor ingredients (e.g. pigment) to make the luminescent paint. When these watches were new, the plots were luminescent all the time, even in the total absence of UV or visible light excitation since the phosphor was excited by the radioactive decay of tritium. However, since tritium has decayed almost completely after several decades, the phosphor will no longer emit in the absence of external excitation by UV or visible light.
Thus, any emission you see upon UV/vis excitation of these dials comes from the phosphor directly, nothing to do with tritium. Some phosphor formulations have degraded chemically and no longer respond to UV excitation. Other formulations still respond to direct excitation but die off after a few seconds. Yet other formulations die off partially after a few seconds, and then have a residual emission for several minutes. Different manufacturers used different phosphor compounds and formulations, and even changed them over the years. Rolex, in particular, changed their formulation significantly over time, from the 60s to the 70s to the 80s. Thus, knowledgeable collectors are well aware of how Rolex phosphors made in different eras should respond to UV light, but they're not always eager to post this detailed information on public forums, for obvious reasons.
In the absence of this detailed knowledge, the most you can do is look for consistency between all of the lume on the dial and hands. Often you will see that one hand, or one marker responds differently, which gives away a relume. If the entire watch and hands have been relumed using paint that incorporates material recovered from old watches, then it will be quite difficult for you to detect the relume unless you have done tests on many similar watches.
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