Radiation test... '55 Sub with radium and original dial

[verticalflight]

1955 Sub with radium plots. Hands were replaced in 1976. Nothing glows at night except the lumos on the second hand.

Bought a $150 Geiger counter off Amazon.

Tests:

- Directly on crystal - 1.75 - 2.25 µSv/h
- 2-3 inches from crystal - 0.81 µSv/h
- 4-5 inches from crystal - 0.50 µSv/h
- Directly on caseback - 0.83 µSv/h

[verticalflight]

Whoops!!!

I tested the watch wrong... you apparently don't use the black hole input looking thing at the top of the unit, you place the item below the unit and test it there (instructions pretty unclear...)

Much higher values than expected:

- Directly on crystal - >9.99 µSv/h
- 1 inch from crystal - >9.99 µSv/h
- 2 inches from crystal - 8.40 µSv/h
- 3 inches from crystal - 5.20 µSv/h
- 4 inches from crystal - 4.80 µSv/h
- 12 inches from crystal - 0.60 µSv/h
- Directly on caseback - 5.40 µSv/h

[linesiders]

Yes, there is a geiger tube in the detector that you are supposed to place over 1 inch or so from what you are measuring (it is in the manual).

[RC2]

What do these readings mean?

[verticalflight]

Well, that basically the radium is still emitting radiation. It does have a half life of like 1200 years so it will continue to do so for a long time.

There is a chart for exposure and it turns out that in the grand scheme of things, wearing a watch putting out 5-10 µSv/h for 4-5 hours at a time is equivalent to the radiation exposure from a flight from NYC to LA. So not much, but more than zero.

https://en.wikipedia.org/wiki/Sievert

[linesiders]

Good thread here: https://rolexforums.com/showthread.p...ight=radiation

Good chart here:

[AS1]

very interesting chart, thanks for posting!

[themaninblack]

Assorted tests have shown that if you wear a Radium dial watch for about 12 hours a day all year (as many people of course did) then you would receive about 3 millisieverts radiation per year from the watch. Will try to find links to post.

Edit - numbers a bit different but this is the article I was thinking of. It's a good one I reckon. http://www.iwcforum.com/Articles/Lum...itaryDials.pdf

[QueueCumber]

Originally Posted by verticalflight

Well, that basically the radium is still emitting radiation. It does have a half life of like 1200 years so it will continue to do so for a long time.

There is a chart for exposure and it turns out that in the grand scheme of things, wearing a watch putting out 5-10 µSv/h for 4-5 hours at a time is equivalent to the radiation exposure from a flight from NYC to LA. So not much, but more than zero.

https://en.wikipedia.org/wiki/Sievert

If you had a Geiger counter with a larger measurement window you would likely find that the piece measures around 90 µSv/h.

At least that is what my 1956 6538 puts out. My 1953 Blancpain Fifty Fathoms puts out over 120 µSv/h...

[linesiders]

Originally Posted by QueueCumber

My 1953 Blancpain Fifty Fathoms puts out over 120 µSv/h...

Photo is now needed, please

[QueueCumber]

Originally Posted by linesiders

Photo is now needed, please

There is a video somewhere on my IG.

Unfortunately, I never uploaded it to flickr and I erased it from my phone, so it's only on my IG.

[QueueCumber]

Found the videos on IG.

Here is the 1956 Rolex 6538:

https://instagram.com/p/2HFZqVjUOH/?...=_queuecumber_

[QueueCumber]

I was incorrect. The Blancpain measured at 223 µSv/h:

https://instagram.com/p/2EBi6zDUDx/?...=_queuecumber_

The device is measuring in millirems and converting to µSv is done by simply multiplying the number by 10.

Needless to say, that is one f***in' hot watch....

[Franks07]

Of course this thread caught my attention due to my radium lume 6205...I'm not getting much radiation exposure these days due to the relative "safe queen" status of this one in my modest collection.
A "hot f***in watch" nonetheless

[linesiders]

Originally Posted by QueueCumber

I was incorrect. The Blancpain measured at 223 µSv/h:

https://instagram.com/p/2EBi6zDUDx/?...=_queuecumber_

The device is measuring in millirems and converting to µSv is done by simply multiplying the number by 10.

Needless to say, that is one f***in' hot watch....

Hot on several levels. Wow.

[verticalflight]

Queue can you test the backside/case side of the watch? I read that the case should dismiss about 2/3 of the radiation.

I am reading 5 microsieverts/hr on the case side, which would suggeset my max reading on the dial side would be about 15. Of course my counter only goes to 10 before limiting.

But wondering what your case side reading would be...

[QueueCumber]

Originally Posted by verticalflight

Queue can you test the backside/case side of the watch? I read that the case should dismiss about 2/3 of the radiation.

I am reading 5 microsieverts/hr on the case side, which would suggeset my max reading on the dial side would be about 15. Of course my counter only goes to 10 before limiting.

But wondering what your case side reading would be...

My pieces are all in the safety deposit box right now, so I can't at the moment. Sorry.

[verticalflight]

No problem
Guess you don't remember the case back reading?

[QueueCumber]

Originally Posted by verticalflight

No problem
Guess you don't remember the case back reading?

I didn't take one...

[phrede]

Very interesting thread!
What is the halftime of Tritium? I can't live with taking ant radiation risks, so I am very eager to learn about radiation from say an old 16660 circa 1984.
Happy 4th July


- via iPhone

[waspy1]

Originally Posted by phrede

Very interesting thread!
What is the halftime of Tritium? I can't live with taking ant radiation risks, so I am very eager to learn about radiation from say an old 16660 circa 1984.
Happy 4th July


- via iPhone

Tritium half life is around 12 years. Your watch is 30 years old so the activity had dropped to less than a quarter of original. It is a low energy beta particle emitter, really nothing to worry about - whether brand new or a few decades old.


Sent from my iPhone using Tapatalk

[verticalflight]

Queue, you were right, I got a different Geiger counter (actually same one you have) and it reads 50-80 microseverts/hr at the watch face.