[time-nuts] Actual life time of a Datum LPRO-101?
namichie at gmail.com
Mon Mar 30 11:22:29 UTC 2009
I have not had any experience with FEI devices,
the LPRO lamp voltage comes from an amplifier
which monitors some internal voltage. I guess they
scaled it to be similar to other rubidium devices.
The lamp requires a very small amount of rubidium to
provide the vapour, which should be at a low pressure
so as to not broaden the spectral line.
The glass envelope may absorb rubidium with time
and this may be the mechanism that limits lamp life.
Hot glass tends to absorb alkali metals.
This is likely because the lamp runs at about 80C.
cheers, Neville Michie
On 30/03/2009, at 9:50 PM, Predrag Dukic wrote:
> Hi, Neville,
> is the same with FEI products; Higher voltage when new, decreased
> with aging?
> Predrag Dukic
> At 12:17 30.3.2009, you wrote:
>> they finish their life when the lamp fades out.
>> When you stoke it up there is a lamp monitoring voltage that
>> is about 10 volts when new but drops below 4 volts at end of life.
>> Otherwise, if it will lock on it is probably a good unit. New users
>> tend not to understand that the frequency trim only covers a range
>> of a few millihertz, which is quite enough to set them right.
>> I have seen comments like" it does not respond to the frequency
>> by users that are used to OCXO standards.
>> The manual is around.
>> Cheers, Neville Michie
>> On 30/03/2009, at 8:41 PM, Ulf Kylenfall wrote:
>>> Does anyone have any experience with the Datum/Efratom LPRO-101
>>> Rubidium standard? There are large amounts of these on e-bay.
>>> The datasheet specifies life time to "at least" 10 years
>>> and the one that I found on a flea market is dated 1999.
>>> I assume that they are replaced as a planned maintenance
>>> and the unit that I found was said to be in good health.
>>> Comments invited
>>> Ulf Kylenfall
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>>> 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/
>> 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/
> and follow the instructions there.
More information about the time-nuts