[time-nuts] Aging rate of crystals

[iovane at inwind.it]

Thanks Rick.

I will study the matter a bit more. Meantime I would tell where my question originated from.
I was referring to a condition where temperature is assumed to be constant.
In the article at http://www.agilent.com/metrology/xtal-policy.shtml (fig. 1) Agilent 
doesn't refer to temperature as a cause of VARIATION of the aging rate, instead they state 
that "The apparent aging rate would also vary considerably depending when the 
measurements were made".
So, my question would more precisely be: is there any known cause (beyond temperature) 
that affects aging rate (that is the speed at which a crystal ages)?

Regards,
Antonio Iovane I8IOV

> For ovenized crystals, any oven temperature change will
> cause aging to temporarily increase (and may change the
> direction as well).  Restabilization may take an hour
> to a day, depending on how much the temperature was changed.
> We haven't noticed that powering up the oscillator or not
> makes a big difference.  (This refers to leaving the oven
> on, and turning off the oscillator circuitry.  This experiment
> is easy to do on a 10811 since the supplies are separate.)
> Does that answer your question?
> 
> Rick Karlquist N6RK
>