Hi,
I am submitting my 105.003 to you for advices (excuse me for my poor english). I bought it last february from my regular dealer. I searched this reference for almost one year until I found it. It has a good dial, case full with still sharp edges, correct insert with some scretches, back with seahorse reporting 105.003-65, perfect 321 mov. running will ser. number 24.53x.xxx, correct crown ...
I would like to have your advices and opinion about hands:
1) l changed the luminova trotteuse with squared tale (wrong) with a service omega luminova spear (I coloured it with decaffeinated coffe and cigar smoke) but it is 0.25 mm shorter compare to the original one; may be you know where I can find and buy an original one;
2) the hours and minutes hands have a green colour too bright, the luminescent
material is tritium (I tested it with Geiger counter), you think that are these the original one or a late Omega service replacement?
Thank you for your attention.
M.

 

The H/M hands look superluminova to me, too green.
I think there are better (shape) chrono hands available but I am not sure.
For me you are right. The H/M hands look out of place.

 

I appreciate your opinion.
Thanks a lot.
M.

 

Geiger counters cannot discriminate tritium from superluminova.
If there is no signal, you can only be sure that there is no radium

 

Hi,
I agree and disagree with you.
I used this detector (from West German Army) switching the probe on beta+gamma I tested some of my watches with tritium dial and hands

for instance my 1965 5512 Submariner, 1966 165.024 Seamaster (tritium) moved the scale hand instrument and It beeped
while my 1985 16750 GMT (I bought it brand new in 1986) didn't move the hand and the detector didn't beep
problably more recent watches have much less tritium.

When I switched the probe on gamma the detector didn't move, it worked very well when I tested my 1958 Submariner.
I never tested luminova o super luminova but I don't think that they emit beta particles.
M.

 

According to my understanding, both radium and tritium are radioactive so should register to some extent on a device designed to detect radioactivity (depending on the sensitivity/settings of the device).

(Super)luminova is non-radioactive.

 

Yes,
radium (half life 1602 years) emits gamma particles while tritium (half life about 12 years) emits beta particles.
You can detect both radiations with the correct instrument.
For tritium this possibility is related to
1) amount of tritium
2) sensibility of the instrument
3) age of tritium
4) the distance between tritium and the probe.

 

Hello Plexyforever,

Very nice instrument that you have !
This military instrument is I guess much more sensitive compared to classic Geiger counters or scintillators available on the market.
I would be interested in knowing about the specs of your device. Do you know by any chance the sensibility for betas and gammas in MeV?

To my knowledge, the energy of the betas emitted by the tritium is very low (0.0186 MeV) and cannot be directly detected with typical commercial Geiger counters, such as the Gamma scout for example (detection limit of 0.2 MeV minimum for betas). Maybe only special instruments such as used in the army or in waste treatment facilities can directly detect tritium. Do you know any commercial detector which can detect tritium ? Neither my gamma-scout or Berthold scintillator can.

It is a surprise for me to read that your device measure directly the betas from tritium, especially considering a source that is more that 50 years old. Within a time of 4 tritium half-lives (48 years), only 6.25 % of the original tritium should remain, not taking into account that approx. 5 % per year of the tritium escape the watch in the form of a gas (according to the swiss SUVA).

In addition, I doubt that any betas can reach your detector if you measure on the plexi. The betas has a very short life time, as they interact very rapidly with the immediate medium (air, plexi) which cause them to deccelerate and thus generating very low energy X-rays (Bremsstrahlung). I think it is more likely that your device measures these X-rays and interprets them as a consequence of the presence of tritum, an indirect measurement so to say.

I don't know much about Rolex or Omega, but the use of promethium147 could explain the fact that you see a signal for betas and not for gammas. It could be that the betas emitted by the Promethium have much higher energy than the betas emitted by the tritium, which might explain that your detector has a signal for betas. However, the half-life of Pm147 is very small : 2.62 years...

Really nice watches btw, dibs on the big triangle ;-)

Cheers,

Fibo

 

Hello Leonardo (Fi-lius Bonacci),
I'm late but I was very busy at work.
The instrument is not mine, I asked to a friend of mine for help so I don't know it's sensibility in MeV.
I think you can find these data on the web. I think you can buy that instrument on eBay it shouldn't be expensive.
Yes I tested the dials and hands without crystal and the detector was very close (< 1.0 mm).
I remember, for example, that the instrument value was 2.75 mCi on the Subamariner 5512 and beeped like crazy.
Have a nice weekend.
M.