Re: Tritium Watch

[LIPTONW@detroitedison.com]

You wrote: 
I recently happened upon a watch that I wore through high school  
>(until 1981) which is a Timex .  On the back is the 3H symbol for   
>tritium.  The small face of the watch dial glows continuously with a  
>dull green glow... 
> 
>Wondering is anyone has seen a similar watch or might know how much  
>tritium was typically used? 
> 
>Thanks. 
> 
>Ron Amoling 
>amolingr@joslab.harvard.edu 
> 
Take a look at NCRP 95, "Radiation Exposure of the U.S. Population From 
Consumer Products and Miscellaneous Sources".  Table 3.2 shows that the 
average activity of a watch using tritium paint is 68.5 MBq.  (I assume that 
this is what your watch has.  There are some watches which use tritium gas to 
backlight a LCD.  These have an average of 7400 MBq of tritium.)  The average 
annual whole body dose from wearing a tritium-activated luminous wristwatch is 
0.6 mrem, with a range of 0.2 - 1.8 mrem/y.   
 
The opinions expressed are strictly mine. 
It's not about dose, it's about trust. 
 
Bill Lipton 
liptonw@detroitedison.com