[time-nuts] temperature sensor

[EWKehren at aol.com]

What I am missing in all these discussions is what do we want to  archive 
or is this an other paper only  discussion. I am used to  starting out with a 
goal, and tackle the challenge from there.
We have a saying in German "Papier ist geduldig.  Translate You  can write 
any thing on paper.  
Bert Kehren
 
 
In a message dated 7/20/2014 12:39:24 P.M. Eastern Daylight Time,  
attila at kinali.ch writes:

Moin,

On  Sun, 20 Jul 2014 07:55:23 -0700
"Tom Van Baak" <tvb at LeapSecond.com>  wrote:

> Thanks for this level of detail. Fascinating. Is the  fundamental physics
> behind the quartz angle-of-cut well understood, or  does this fall into
> advanced alchemy and industrial magic?

>From  what i gathered from my excursion into solid state phyiscs, the
properties  of crystals can be calculated "easily". If i'm not mistaken
the SC cut was  calculated before it was experimentally proven (sorry,
cannot find the  reference for that).

There are also several software packages to  simulate quartz crystals.
(e.g. CS-01 from maxis-01)


> I  understand about the time constant now. Yes, on the order of a
> few  seconds makes sense. Would it be possible to have other mounting
>  techniques that improve environmental contact with the crystal?

The  problem here is, that any closer contact will lead to damping
of the  crystal. Probably the best solution is, as Bob Camp said,
to use SAW  instead of BAW.

> Do you know of any commercial quartz crystals  (say, in the $1 to $10 
range)
> that have been optimized for large  tempco at room temperature? Or 
optimized
> for linearity over a large  range (e.g., -40 to +40 C)?

As Bernd Neubig mentioned, Axtal has  some:
http://www.axtal.com/English/Products/PiezoSensors/TemperatureSensors/

As  none of the usual distributors carries them, i have no idea what
the price  is. Maybe Bernd can answer that question.

I'm pretty sure other quartz  manufacturers have some as well.

> I was able to test
> one  once, a 5x7mm XO, but I don't know any more about it other than it  
came
> from Switzerland.

Hmm... The only quartz manufacturer in  Switzerland that is still producing
anything, is AFAIK Microcrystal. I'm  not aware of any other (after 
Oscilloquartz got bought and their quartz  business integrated into 
Microcrystal).

Unless you got it over Quarz AG  (www.quarz.ch) which is merly a 
distributor.
(Yes, they sell beauty  products too... )

BTW: for some reason, i did not get the two mails  from Andras Pummer
which you quoted at the end of your mail. They don't  seem to be in
the archives either.

Attila Kinali


-- 
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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
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