Identifying watch for possible radioactive concern

[kr2]

Hi there - recently picked up this watch to practice on. Crossed my mind that I'm not sure how old it is, and if it's 60s or earlier might have radioactive lume? Don't have a Geiger counter and am hoping someone can identify and weigh in please. Dial says "Cornell", movement says "Shriro watch Inc", case back inside says "TK Co, made in France". Any info would be helpful and much appreciated please, thank you!

[Geotex]

Sometimes you can see a burn mark on the dial from hands that have stayed in one place for decades, which is a clincher, but I don't really see that here. 

An inexpensive detector could let you know for sure, but considering the dial/hand style and the darkened condition of the dots on the dial in the absence of any clear water damage, I'd give 90% likelihood that there is radium there.  Tritium is usually marked out on the dial, and although it moves to yellow and tan as it ages, it doesn't get as "toasty" as those dial spots based on what I've seen.

[oldhippy]

I shouldn't worry you are not going to end up glowing green in the dark. Looks like mid 50's to 60's watch. 

[rjenkinsgb]

28 minutes ago, Geotex said:

An inexpensive detector could let you know for sure

Definitely worthwhile, if you are working with old watches - just be sure it's an actual Geiger counter, not one of the vast range of scam/fake "Radiation detectors" on ebay & amazon etc. that detect RF or static electricity...

 

In the mean time, I'd put the dial and hands in zip bags & wipe down the work area with a damp cloth to pick up any dust, then discard the cloth.

The emitted radiation from radium lume is not normally harmful - but inhaling or ingesting a single particle of the material can cause serious long term harm, so do take care with it.

 

[kr2]

Thanks all. I had ordered a Geiger that's showing up today but was hoping someone might be able to identify the watch to help me get ahead of it, so thank you Geotex. I in no way planned or plan to risk my health over watches and will probably trash this to be safe, it just stupidly didn't register for me how old this watch could be before I had opened the thing up. Sticking to explicitly newer watches going forward.

 

The counter I ordered is a GQ GMC model, which I have seen mentioned and used by many people and seems to be legit. https://www.gqelectronicsllc.com/comersus/store/comersus_viewItem.asp?idProduct=5786

Edited May 5 by kr2
Adding info about Geiger counter purchased

[kr2]

Well, Geiger counter showed up today and the dial and/or hands were extremely radioactive, reading quickly spiked from a baseline of 10-20 cpm to 100 and was still rising when I removed it. Trashed the whole thing. Thankfully nothing else outside the components was registering - work surface, tools, the paper I had used to clean off some components.... 

 

And now I have a Geiger counter to use to  check practice watches BEFORE disassembly

Edited May 6 by kr2
Typo

[ScrewDropper]

On 5/6/2024 at 7:29 AM, kr2 said:

Well, Geiger counter showed up today and the dial and/or hands were extremely radioactive, reading quickly spiked from a baseline of 10-20 cpm to 100 and was still rising when I removed it. Trashed the whole thing. Thankfully nothing else outside the components was registering - work surface, tools, the paper I had used to clean off some components.... 

 

And now I have a Geiger counter to use to  check practice watches BEFORE disassembly

To be honest,I would not rely on cpm for a measurement, particularly with radium. The radium is a particle radiation and this cannot penetrate the skin. It has to be ingested (i.e. inhaled) to have an affect. A more reliable measurement of this kind of radiation is the Sievert, which, roughly, is the affect of radiation.  Broadly speaking, when dealing with radium, precautions such as breathing equipment and removing radium in a fluid is advised. Disposal is also something to consider. It's generally a pain in the arse to dispose of and you are better just leaving it undisturbed

[Geotex]

Isn't it most correct to say that the mixture of radium decay pathway compounds found in old lume will produce both alpha and beta particle radiation as well as gamma rays, so it's over-simplistic to dismiss it all as low-energy particle emission? True, a cheap geiger counter chirping away with a raw CPM count won't specifically give you the relevant biological dose, but it makes it easy to tell the difference between your local background, a watch with a bit of activity, and one that is comparatively quite active. Each person can make their own risk analysis based on their understanding and concern, but there's nothing wrong with using an inexpensive meter to help make the determination.

[Waggy]

11 hours ago, Geotex said:

sn't it most correct to say that the mixture of radium decay pathway compounds found in old lume will produce both alpha and beta particle radiation as well as gamma rays, so it's over-simplistic to dismiss it all as low-energy particle emission?

Here is the radium decay chain, as you can see it decays into alpha emitters until you get to lead, but it's first decay product is radon with a half life of 1600 years, so  we will all be long dead before the radium on our watch starts emitting anything we need to be overly concerned about.

[Geotex]

But the radium wasn’t pure when put on the watch, so it’s already a mixture. We certainly can see counts from watches that penetrate materials that would stop alpha radiation. Again, I’m not paranoid about it, but it shouldn’t be completely discounted when people ask about it.

Edited June 14 by Geotex