[time-nuts] Can anyone spare an LPRO lamp?

Brian Kirby kilodelta4foxmike at gmail.com
Tue Sep 29 23:07:38 UTC 2009


I have attached a low res scan of Robert J. Carpenter's paper NBS 
Technical Note 235, issued April 6, 1964.  Its a rubidium standard that 
was made for NBS.  Its the technical specs on the lamp.  I'm sure they 
probably do it a little different now, but it should give an idea about 
what went into the lamp.

Brian - KD4FM



Bob Camp wrote:
> Hi
>
> The exact "fill" in the lamp is one of those things the Efratom does not
> like to talk about. Best guess is that there is more than just Rb in there.
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Neville Michie
> Sent: Tuesday, September 29, 2009 12:19 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Can anyone spare an LPRO lamp?
>
>
> The lamp in the LPRO may have a significant difference from the other  
> lamps.
> The pictures of lamps on Tom's ? page show that each of them has a  
> side arm
> which is most helpful for filling.
> The side arm is left out in the cold so any excess rubidium condenses  
> there
> as a reserve supply. The vapour (vapor) pressure of rubidium is then  
> determined
> by the temperature of the side arm.
> The LPRO does not seem to have a side arm, at least I did not see one  
> when
> I looked at mine, and if it has it does not seem to protrude out of  
> the oven.
>   I can not guess how they filled it. Remember it is mainly empty, I  
> think, although
>   it may have an inert gas in it besides the rubidium vapour. With  
> the right amount
> of rubidium in the tube the pressure will always be right, the only  
> problem is that
> alkali vapours are infamous for diffusing into warm glass, and with  
> no backup supply
> of rubidium the vapour pressure will drop and the fire will go out.
> Can anyone tell me what the lamp looks like? Mine seems to be a  
> simple glass
> sphere.
>
> cheers, Neville Michie
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>   
-------------- next part --------------
A non-text attachment was scrubbed...
Name: rubidium.pdf
Type: application/pdf
Size: 24866 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20090929/3786ab07/attachment-0001.pdf>


More information about the time-nuts mailing list