[time-nuts] quartz thermometers

[Bill Hawkins]

It may be that the need for that kind of resolution died out.

The next step up from quartz thermometry is resistance thermometry.
The linearization equation for platinum has enough terms to make it
uncertain around .01 C.
Temperature calibration baths usually use platinum resistance sensors.

It may be that the triple point of water does not have the certainty to
reach '0.0001C'

Disclaimer: I only worked with industrial sensors from Rosemount, Inc.
as an employee.

Bill Hawkins


-----Original Message-----
From: Alan Ambrose
Sent: Friday, March 11, 2016 11:42 AM

Hi,

I hope this is still relevant and not too off-topic...but since it
involves crystals and tempco...

Quartz thermometers (e.g. the HP 2804A) with their 'linear cut' crystals
and '0.0001C resolution' seem to have been a thing from the mid-60's to
the mid-80's:

http://www.hparchive.com/Journals/HPJ-1965-03.pdf

There still appear to be some manufacturers making the crystals:

http://www.statek.com/products/pdf/Temp%20Sensor%2010162%20Rev%20B.pdf

Anyone know why they died out? Did a better technology replace them?

TIA, Alan