Omega 2531.80 never used tritium (?)

Joao_BRA · Oct 28, 2025

Hi all,

I asked Omega about the use of tritium in the 2531.80.00 models. The doubt lay in the fact that there was no "tritium" marking on the dial, but the general community claims that the early dials, which yellowed and lost luminous efficiency over time, used tritium.

Apparently, Omega never used tritium in the 2531.80.00. I therefore deduce that the yellowing must be due to the use of some kind of Luminova resin mounting base, which has been altered over time.

What do you guys think?

Joao_BRA · Oct 28, 2025

@Archer Can you help us? What do you think?

YY77 · Oct 28, 2025

Watchbase has start of production from 1993, if true first ones have tritium;

Screenshot_20251028_154838_Chrome Beta.webp

ErichPryde · Oct 28, 2025

Joao_BRA
I therefore deduce that the yellowing must be due to the use of some kind of Luminova resin mounting base, which has been altered over time.

The response from Omega leaves something to be desired.

Please note that in the response it is noted that dial reference 064PP3033001 replaces dial reference 064TP3033001. These numbers are identical. This is likely a typo. I'd be curious what Archer says the original dial reference for the 2531.80.00 actually is, because this info is confusing.

(EDIT: CORRECTION: I just noted that the two dial references are different- a P replaces the "T" in the first dial reference. I think it's likely that the Omega rep is just wrong and I'd bet the "T" denotes tritium and the "P" denotes phosphorescent or something.)

Please note that the response states "Omega stopped producing Tritium luminescent material around 1997." This is correct, but doesn't really answer whether or not all dials from before 1997 were Tritium or not.

"All" 2531.80.00 Seamaster Professionals produced from 1993 until sometime in 1997 had Tritium dials originally. There is essentially zero room for doubt on this, and the person from Omega you are talking to has made a mistake, likely pulling the wrong dial reference and assuming based upon that info. Omega uses a paint that contains Zinc Sulphide, which luminesces briefly when exposed to strong light sources. The beta particles emmited from the tritium excite the ZnS, which is what makes it emit visible light until the tritium is exhausted. This is why these dials today will glow briefly if exposed to strong light, but unlike modern luminova, cannot maintain that glow for particularly long. At this point the tritium in these dials is depleted enough that it is not able to energize the dials particularly well.

Regarding your doubt about the lack of a disclaimer for tritium on the dial: It's important to note that ISO 3157 allows for Tritium dials to be optionally marked as Tritium if the radioactive component falls under a certain threshold. Meanwhile, dials that are over that threshold must be marked Ⓣ or T > 25. Omega was very consistent in labelling their Speedmaster Professional dials T SWISS, which was the optional marking for tritium under a certain threshold. But, they weren't quite as consistent in labelling everything else with tritium as containing it and there are dozens and dozens of examples of unmarked tritium dials.

This constant misunderstanding is because it is assumed by so many people today that "the law" was as simple as "has tritium, must be marked," but this isn't correct.

Also, ISO3157 changed in 1991, a few years before the release of the 2531.80, and this may have impacted Omega's decision to mark (or not mark) the dials.

From the Foundation of Haute Horology

Joao_BRA · Oct 28, 2025

ErichPryde
The response from Omega leaves something to be desired.

Please note that in the response it is noted that dial reference 064PP3033001 replaces dial reference 064TP3033001. These numbers are identical. This is likely a typo. I'd be curious what Archer says the original dial reference for the 2531.80.00 actually is, because this info is confusing.

(EDIT: CORRECTION: I just noted that the two dial references are different- a P replaces the "T" in the first dial reference. I think it's likely that the Omega rep is just wrong and I'd bet the "T" denotes tritium and the "P" denotes phosphorescent or something.)

Please note that the response states "Omega stopped producing Tritium luminescent material around 1997." This is correct, but doesn't really answer whether or not all dials from before 1997 were Tritium or not.

"All" 2531.80.00 Seamaster Professionals produced from 1993 until sometime in 1997 had Tritium dials originally. There is essentially zero room for doubt on this, and the person from Omega you are talking to has made a mistake, likely pulling the wrong dial reference and assuming based upon that info. Omega uses a paint that contains Zinc Sulphide, which luminesces briefly when exposed to strong light sources. The beta particles emmited from the tritium excite the ZnS, which is what makes it emit visible light until the tritium is exhausted. This is why these dials will glow briefly if exposed to strong light, but unlike modern luminova, cannot maintain that glow for particularly long.

Regarding your doubt about the lack of a disclaimer for tritium on the dial: It's important to note that ISO 3157 allows for Tritium dials to be optionally marked as Tritium if the radioactive component falls under a certain threshold. Meanwhile, dials that are over that threshold must be marked Ⓣ or T > 25. Omega was very consistent in labelling their Speedmaster Professional dials T SWISS, which was the optional marking for tritium under a certain threshold. But, they weren't quite as consistent in labelling everything else with tritium as containing it and there are dozens and dozens of examples of unmarked tritium dials.

This constant misunderstanding is because it is assumed

Also, ISO3157 changed in 1991, a few years before the release of the 2531.80, and this may have impacted Omega's decision to mark (or not mark) the dials.

From the Foundation of Haute

Thanks for the information. I didn't know the tritium marking could be omitted in some cases.

In any case, I only shared the information to help the entire community advance the hobby.

Archer · Oct 28, 2025

So this is not easy to explain, and you have to kind of deduce what is being indicated even though it's not directly being said. What I mean by that is that there is no place where Omega explicitly states that hands or dials have Tritium, but that doesn't mean we cannot deduce that they do.

As noted, there are 2 letters in the dial part number. TP for the original dial, and PP for the current dial. So let's look at Omega Work Instruction 61, which is called material codification. I'll include 4 designations to make this point. The first two listed are not longer "active" which is a key point.

"TP - Metal plate, index painted" - this is what the original dial was for the Bond watch, so painted indexes
"TT - Metal plate, metal index" - this would be for a dial with applied markers with luminous material

"PP - Superluminova, index painted" - this is the current designation for the Bond watch dial
"PT - Superluminova, metal index" - this is the current designation for a dial with applied markers with luminous material

So on the Bond watch dial, the email you received claims that all dials were Luminova. But if that was true then why would they change the designation for TP to PP, and only state that the PP version uses Luminova in work instruction 61?

The only thing I can conclude is that TP did not stand for Luminova.

Here's another data point that to me is basically the smoking gun - if I look up the Speedmaster dial for the time period when we know they were equipped with and marked as Tritium dials, here is the part number:

064TP3052001

The new dials are:

064PP3052001

So clearly for Speedmaster dials, TP meant Tritium, but they say that the same material code was not Tritium on the Bond watch? That makes zero sense. The point of these codes is to be able to tell what the material is just from the part number, and if that meaning changes based on what watch the part is on, then the entire system fails to do what it is supposed to do.

So most likely whoever answered that email is not a "technical" person, and really has no idea.

Hope this helps.

ErichPryde · Oct 28, 2025

Correction to my earlier post: I was a bit uncertain about the Ⓣ marking, so did a bit of reading. I had that wrong- from what I've read I understand that the British Royal Navy required this marking on tritium lumed watches, which is why you sometimes see SM 300s from the 60s marked with "Ⓣ." But the British Royal army did not require any additional marking over the ISO standard, so "W10" watches that have tritium lumed sometimes do not have the "Ⓣ" marking.

Interesting bit of history.

ErichPryde · Oct 28, 2025

Archer
So this is not easy to explain, and you have to kind of deduce what is being indicated even though it's not directly being said. What I mean by that is that there is no place where Omega explicitly states that hands or dials have Tritium, but that doesn't mean we cannot deduce that they do.

As noted, there are 2 letters in the dial part number. TP for the original dial, and PP for the current dial. So let's look at Omega Work Instruction 61, which is called material codification. I'll include 4 designations to make this point. The first two listed are not longer "active" which is a key point.

"TP - Metal plate, index painted" - this is what the original dial was for the Bond watch, so painted indexes
"TT - Metal plate, metal index" - this would be for a dial with applied markers with luminous material

"PP - Superluminova, index painted" - this is the current designation for the Bond watch dial
"PT - Superluminova, metal index" - this is the current designation for a dial with applied markers with luminous material

So on the Bond watch dial, the email you received claims that all dials were Luminova. But if that was true then why would they change the designation for TP to PP, and only state that the PP version uses Luminova in work instruction 61?

The only thing I can conclude is that TP did not stand for Luminova.

Here's another data point that to me is basically the smoking gun - if I look up the Speedmaster dial for the time period when we know they were equipped with and marked as Tritium dials, here is the part number:

064TP3052001

The new dials are:

064PP3052001

So clearly for Speedmaster dials, TP meant Tritium, but they say that the same material code was not Tritium on the Bond watch? That makes zero sense. The point of these codes is to be able to tell what the material is just from the part number, and if that meaning changes based on what watch the part is on, then the entire system fails to do what it is supposed to do.

So most likely whoever answered that email is not a "technical" person, and really has no idea.

Hope this helps.

Thanks for the added info. Fun stuff.

Joao_BRA · Oct 28, 2025

Archer
Portanto, isso não é fácil de explicar, e você tem que deduzir o que está sendo indicado, mesmo que não seja dito diretamente. O que quero dizer com isso é que não há nenhum lugar onde a Omega declare explicitamente que ponteiros ou mostradores contêm trítio, mas isso não significa que não possamos deduzir que sim.

Como observado, há duas letras no número de peça do mostrador. TP para o mostrador original e PP para o mostrador atual. Então, vamos analisar a Instrução de Trabalho 61 da Omega, que se chama codificação de material. Incluirei quatro designações para ilustrar esse ponto. As duas primeiras listadas não estão mais "ativas", o que é um ponto fundamental.

"TP - Placa de metal, índice pintado" - este é o mostrador original do relógio Bond, então os índices foram pintados
"TT - Placa de metal, índice de metal" - isso seria para um mostrador com marcadores aplicados com material luminoso

"PP - Superluminova, índice pintado" - esta é a designação atual do mostrador do relógio Bond
"PT - Superluminova, índice de metal" - esta é a designação atual para um mostrador com marcadores aplicados com material luminoso

Então, no mostrador do relógio Bond, o e-mail que você recebeu afirma que todos os mostradores eram Luminova. Mas se isso fosse verdade, por que mudariam a designação de TP para PP e declarariam apenas que a versão PP usa Luminova na instrução de trabalho 61?

A única coisa que posso concluir é que TP não significa Luminova.

Aqui está outro dado que, para mim, é basicamente a prova cabal: se eu procurar o mostrador do Speedmaster para o período em que sabemos que eles eram equipados e marcados como mostradores de trítio, aqui está o número da peça:

064TP3052001

Os novos mostradores são:

064PP3052001

Então, claramente, para os mostradores Speedmaster, TP significava Trítio, mas eles dizem que o mesmo código de material não era Trítio no relógio Bond? Isso não faz sentido algum. O objetivo desses códigos é conseguir identificar o material apenas pelo número da peça, e se esse significado muda dependendo do relógio em que a peça está, todo o sistema deixa de fazer o que deveria.

Então, provavelmente quem respondeu ao e-mail não é uma pessoa "técnica" e realmente não tem ideia.

Espero que isso ajude.

Thanks for your time. Great answer.

Omega 2531.80 never used tritium (?)

Joao_BRA

Joao_BRA

YY77

ErichPryde

Joao_BRA

Archer

ErichPryde

ErichPryde

Joao_BRA

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