[time-nuts] FE-5680A Rb lamp subject to wearout?

Magnus Danielson magnus at rubidium.dyndns.org
Mon Nov 14 17:45:39 EST 2011

On 11/14/2011 11:25 PM, beale wrote:
> I've decided I can't pass up a rubidium standard at this price, having seen the reports here that the units work. Just one question: it was my impression that the rubidium in such a device gets somehow used up over time. Can anyone hazard a guess as to how long this might keep running?  The FE-5680A data sheet at http://www.freqelec.com/pdf/rfs_12pg.pdf seems to be silent on the subject of wearout.
> Should I expect that this sort of repair procedure will soon be necessary? http://www.ko4bb.com/Manuals/05%29_GPS_Timing/Efratom/Efratom_FRS_Lamp_assembly_repair.pdf

If you get a thin layer of rubidium on the lamp surface, the normal lamp 
operation is unable to remove it but it will filter out the wavelegnth 
we want from the lamp and thus the effective lamp intensity suffers. 
Raising the temperature futher will have that complexion release itself 
and you can concentrate all rubidium to the storage droplet. There are 
lamp-designs which is built to resolve this "wear" mechanism on 
cold-start, but I think there is very few of those rubidiums around 
these days.


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