[time-nuts] temperature sensor

[Bill Dailey]

Ice water and boiling water coupled with altitude will give you two points.

Sent from mobile

> On Jul 21, 2014, at 10:12 AM, Attila Kinali <attila at kinali.ch> wrote:
> 
> On Mon, 21 Jul 2014 04:39:51 -0700
> Alexander Pummer <alexpcs at ieee.org> wrote:
> 
>> NTC are not that very stable, they are amorphous material winch could 
>> recrystallize slowly and therefore change it's electrical behavior , 
>> PT100 style is more reliable since it is pure metal
> 
> How long is the time constant for NTCs?
> I guess, it wouldn't matter for most of the measurements we do,
> as NTCs need to be "calibrated" before precision measurements
> anyways. Unless one measures over several months, or years.
> But on this timescales, i wouldn't really trust an off the shelf
> PT100 either. Not unless i measure its stability
> 
> For use in GPSDOs and OCXOs, i guess it doesn't really matter,
> as long as the NTC stays within spec. There an external loop
> corrects for the variation/drift of the measurement.
> 
> 
> While we are at it: what is a good way to calibrate/characterize
> temperature sensors that is available to hobbyists?
> 
>            Attila Kinali
> 
> -- 
> I pity people who can't find laughter or at least some bit of amusement in
> the little doings of the day. I believe I could find something ridiculous
> even in the saddest moment, if necessary. It has nothing to do with being
> superficial. It's a matter of joy in life.
>            -- Sophie Scholl
> _______________________________________________
> 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.