[R-390] meters arrived

[Mahlon Haunschild]

Correction: the stuff on the glass is most likely 210Pb, not 214Pb or 
214Bi.  But the decay of the latter two is where the beta particles come 
from.

regards,

m.

Mahlon Haunschild wrote:
> The surest way to detect this is to use a Geiger counter (won't detect 
> the alpha particles that the radium emits, but will detect the beta 
> particles from the decay products.
> 
> Follow this at your peril:  If the phosphor has turned brown and/or 
> doesn't glow after shining a bright light on it, it contains radium.  If 
> its white (or mostly white) and/or glows after light exposure it should 
> be OK.  If the glass is cloudy it's hot (those are radon decay products 
> deposited on the glass like 214Pb and 214Bi, and those are hot too!), 
> otherwise it's OK.
> 
> FWIW, I tested all of my meters with a Geiger counter (a new, sensitive 
> one, not an ancient CD unit that's only capable of telling you that 
> you're dead).  The Simpson and International meters I have/had were 
> radioactive.
> 
> regards,
> 
> Mahlon - K4OQ
> --------------------------------------------------------------------------------- 
> 
>>
>> Subject:
>> [R-390] meters arrived
>> From:
>> <ka9egw at britewerkz.com>
>> Date:
>> Thu, 10 Sep 2009 14:35:52 -0500
>> To:
>> <R-390 at mailman.qth.net>
>>
>> To:
>> <R-390 at mailman.qth.net>
>>
>>
>> well, I got the meters today.  They're phaostron units, and a phone 
>> call to
>> them talking to Tony who was involved in meter sales to R390a contractors
>> early in his career, reveals these are "most likely" 100 ohms.
>>
>> He also told me from 1962 on wards, the spec on r-390a meters changed 
>> from
>> "s" for self-luminant to "p" for "phosphorescent", which means there may
>> well be many 390A meters pulled that are not radioactive at all.  How to
>> tell the diff, I haven't a clue...
>>
>> Now to see about testing one of these puppies...
>>
>> 73, Brian
>>
>