[time-nuts] Question for the cesium nuts.

Rick Karlquist richard at karlquist.com
Sat Mar 17 13:42:14 UTC 2007


Having worked on the HP 10816A rubidium clock 25 years ago,
it is hard for my to believe the lamp alone could last 56
years on the average.  Even ordinary light bulbs don't last
that long.

Rick Karlquist N6RK

SAIDJACK at aol.com wrote:
>
> In a message dated 3/16/2007 18:32:58 Pacific Daylight Time,
> martelno at yahoo.com writes:
>
> Also,  some high end rubidium (such as Perkin-Elmer)
> manufacturers are able to  develope 133Rb clocks having
>> 450 000 hours MTBF! That'a a lot of  nanoseconds!
>
>
>
> Hi Jack,
>
> we cannot expect the units to work that long. Hard Disks have >50K MTBF,
> and
> fail all the time in much less time depending on how they are used  etc.
>
> MTBF is a mean, meaning in the real world the Perkin Elmer unit  could
> fail
> in the first 10 minutes, just that the statistics for that to  happen have
> pretty low probability.
>
> When they calculate MTBF, they probably don't take into account external
> effects such as AC voltage spikes due to janitors pluggin-in vacuum's or
> due to
> lightning etc, earthquakes, user obuse, water damage, movement, effects of
> UV
> light on plastik parts such as cables, Tin Whisker shorts, electrolytic
> capacitor dryout, mouse damage, etc. I think it's pretty useless to say a
> piece
> of equipment has a MTBF of over 50 years. Then again that's only an
> opinion...
>
> bye,
> Said
>
>
>
> ************************************** AOL now offers free email to
> everyone.
>  Find out more about what's free from AOL at http://www.aol.com.
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>






More information about the Time-nuts_lists.febo.com mailing list