Hi everybody, I own an A278 and it is one of my 2-3 best watches though I own some more expensive.
Very wearable.
I have 2 questions:
1) indices’ lume is become green/light blue (or maybe they were made like this), which materials are they made? I think also tritium but also something else. Did someone have see other watches with lume like this (also other brands)? Zenith extract don’t help me, it says only “highly luminescent hour markers”
2) what is useful for the 0-100 scale? Only to indicate the percent of minute or something else? I never seen it before.

Thanks to who will help me

 

Lovely watch. I would like to own the three register A277 one day.
The decimal scale is/was used on chronographs in science and industry applications to divide time into decimal fractions making long calculations easier. Can be found on external fixed bezels or internally as on your watch.
At least I think that's it, I am neither a scientist nor a captain of industry.
Cheers.

 

Thanks for your explanation!
Even if I love much more small watches (max 40mm), A277 is also in my dreams...
On A277 research, in my opinion, the difficoult is to find one with bracelet and with a good bezel
A278 was a discovery for me, it was a bit unknown but it was perfect on my wrist and the dial is ipnotic

 

Beautiful watch! As it was produced in the 70s, I am pretty sure the lume is tritium. Color and texture look convincing and also show signs of aging.

 

did you check the reaction to uv light? from the macro shot one could suspect that most of the yellow lume flaked off, revealing the slightly white-green printed markers on the dial

 

☝️Good idea to hold a UV light to the dial and see how much glow you get. It does seem like some of the lume has flaked off. Besides that I feel like I’ve seen Zeniths during this time period exhibit a similar color change to the light geeen you describe.

 

I have seen greenish tritium on many watches over the years. I suspect it is typical for 70-80s models, even some Speedmaster with a green hint in lume are around so nothing to worry about.

however, in case of this A278 my vote goes for flaked off lume

 

Thanks for your information, next weekend I will try the UV light and I will post a photo!

 

No worries. I have come across a couple of really good A277 for sale with bracelet but the prices are very high. I need to save some money or sell some watches.
All the best.

 

Very nice example of A278, lovely.

Progress to green tritium is very common. Every brand could use different combination of tritium with other materials, and the degradation was different in each of them.

I am looking for A277 too, not really worried about the bracelet or bezel (I have one, in Nos condition), but the condition of the dial (lot of them with poor condition on subdials, or the external scale) and matching tritium are things you can’t solve, so it is that is most important to me.

 

In seikos their lume is green even from the early 60'ss I don't think this is anything untoward