Interestingly, the use of AC-cut crystals (high linear tempco of frequency) is found in the development of OCXOs. Using a reference AC-cut resonator - in place of the final AT/SC resonator - one can learn much about the thermal characteristics of the oven loop performance. While not a precise temp sensor, it is a high sensitivity indicator of temperature variations of the resonator.
On Fri, Mar 11, 2016 at 11:44 PM, Bill Hawkins <bill.i...@pobox.com> wrote: > 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 > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
