Tritium dials and hands are getting rare.

Only some of those older watches with tritium luminous are in authentic condition. The yellow colour of tritium often fits perfect to those watches. So I decided to keep my Ocean as it is, with Tritium.

Some watches have a mixture of zinc sulphate and tritium. The zinc sulphate can store the light of the environment similar like super luminova, but only for some minutes and less intensive.

This mixture was used for several models, Ing. 1832/3003 and some Oceans as well. But NOT for that one, I used for testing !

Tritium has a half-live of 12.3 years. But the tritium luminous can work much longer, because much less than half of the tritium energy is enough for the luminous.

It is easy to take night shots of super luminova dials, but photos of tritium dials need more effort.

I estimate, the light power of LS : tritium is about 100 : 1 or less.

As an example, I used a 3003 dial from 1979 (tritium with zinc sulphate) and an Ocean dial from 1985 (tritium only) for testing the tritium intensity. Even after aprox. 30 years, the tritium luminous still works.

A photo lens with a Aperture Ratio of 1:0.95 was very helpful to create these photos.

Regards

HEBE

Hi Hebe,

Very nice shots.
I didn't know about the zinc sulphate.
Very interesting.

Thanks for the details and pictures. What shutter time did you use? I guess 'speed' wouldn't be the correct word here ;-)

Kind regards,

Clemens

Indeed Clemens,

the max. shutter time was 30 seconds for the Ocean dial, but with fixed ISO 200 !!

Greetings
Heiko

Very interesting comparison and brilliant pictures, thank you.

May I ask you what's your source?

I am not a native speaker.
Sorry, I do not understand your question ?!

Regards

Heiko

A very interesting comparing and needle-sharp photographs!
Congratulations Heiko!

Besides your craftmenship, the dial and the watch, the NOKTRON lens is the star. ;-)

Two additional questions:
Is it really zinc sulfate (ZnSO4) or zinc sulfid (ZnS)due toits luminescence ?
Do you have informations about the half-lives of the ZnS, Tritium, the ZnS/Tritium mixture and the mixing ratio of this compound?

Regards

might this be useful ? Not sure of its accuracy and authenticity...apologies if one of u guys actually am the writer !

kronometric.org/article/lume/

Sorry,

I just wanted to know, where did you get the information about the zinc sulphate and tritium mixture, used in several references?

It's an interesting point to me and I would like to know where this info is available, besides your precious post.

Hi Hajo,
The half life of tritium is a short 4,500±8 days (approximately 12.32 years). The half-life of Radium 226 is 1,601 years, so dials of the W.W.W. and of the Mark 11s with original dials will be luminescent for quite a while, without the need to be exposed to light. The paint, however, will deteriorate over time because the mixture is unstable.
I believe that we can't speak in terms of hal-life when referring to ZnS, since Zinc and Sulphur are stable elements and do not decay. The reason why ZnS based paint deteriorates may have to do with the other ingredients in the paint.

@Roberto and Hajo.

Indeed there are not many informations available about this very special topic. I could not found any specific IWC information, but some hints in articles and the R-L-X.de/forum.

Some links to articles:

www.orau.org/ptp/collection/radioluminescent/radioluminescentinfo.htm

www.uhren-muser.de/static/Panerai_30873.html

www.info-uhren.de/technik/leucht/uhrenleuchtfarben.htm

Many other are available too.

Regards

Heiko

Heiko,

Thanks for clarification. I knew the first link, not the other 2.

You've already replied to that but, saying:

You made me curious.

My question is: how to get information about different mixtures used in IWC dials?

Does it depend, for instance, by the dial supplier, so, being aware of which compound, a particular supplier used within a certain period, you can define what indexes - coming from that supplier - are made of?

Well Roberto, I am looking for exactly those specific information about IWC components since some years, but without success yet.

So, I can not answer your IWC specific question.

But there is not any hint, that IWC did not use the "standard" luminous material at that time.

My primery point was to show, that such old dials and hands are still working and that there were different mixtures of luminous material.

Regards

Heiko

Heiko, thanks.

Good post, full of potential developments also.

Interesting Heiko that the elder Tritium/ZnSO4 compound shows a better result in keeping his luminosity after 30 years than the younger Tritium of the Ocean. Obviously the zinc sulfate as a carrier prolongates the luminous effect.

Regards