I'm looking for multiyear data from precision voltage references from initial power on which includes time-date, temperature and voltage. Relative humidity would also be nice if it is available. I am a retired PhD level oil industry research scientist. I spent a number of years heavily involved in the mechanics of materials. I also spent several years working on sparse L1 pursuit (aka basis pursuit) solutions to inverse problems involving the 1D heat equation as it describes 1D fluid flow in porous media which is important to understanding the behavior of shallow reservoirs after fracking. The aging curve for references appears to be of that general form so I'd like to take a crack at seeing how accurately I can forecast the aging drift. Prior experience and testing solutions of the heat equation indicate that one can make good predictions for a period equal to the length of the prior history. So if anyone has multiyear data and is willing to share the first half of the series with me I'll see what I can do. It would be helpful though, to have the full series for a few references with long histories so I can test myself before submitting the results for general scrutiny. In considering integrated circuit device construction, it seems likely that both the aging drift and the voltage hysteresis caused by thermal excursions are related to the different coefficients of expansion of gold, aluminum and silicon at the wirebond. In particular, I suspect thermoviscoelastoplastic deformation as the mechanism. However, I have not seen a photomicrograph of an LTZ1000 reference die showing the bonding details. If anyone knows of such I'd be grateful for a link. For reference, Feynman demonstrated thermoviscoelastic deformation at the Challenger hearing in his famous C clamp and ice water experiment. In the case of a voltage reference one must also consider plastic deformation to be able to account for a permanent change in the value. Thanks, Reg

On Tue, 27 Aug 2019 at 22:16, Reginald Beardsley via volt-nuts < volt-nuts@lists.febo.com> wrote: > > I'm looking for multiyear data from precision voltage references from > initial power on which includes time-date, temperature and voltage. > Relative humidity would also be nice if it is available. One issue I suspect that you will need to consider is if Instruments with LTZ1000As have been powered on 24/7 as some people leave them, or turned on/off as needed. See http://literature.cdn.keysight.com/litweb/pdf/3458A-18A.pdf Dave -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@kirkbymicrowave.co.uk https://www.kirkbymicrowave.co.uk/ Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales. Company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom

Hi Reg I have been keeping a spreadsheet on a number of LM399 refs that I have been running in for over 12 months. The data consists of non-regular spot checks of the zener (~7v) and 10v outputs using a Keysight 34461A. Not sure this it would be of use in your analysis. Lou On Wed, Aug 28, 2019 at 7:16 AM Reginald Beardsley via volt-nuts < volt-nuts@lists.febo.com> wrote: > > I'm looking for multiyear data from precision voltage references from > initial power on which includes time-date, temperature and voltage. > Relative humidity would also be nice if it is available. > > I am a retired PhD level oil industry research scientist. I spent a > number of years heavily involved in the mechanics of materials. I also > spent several years working on sparse L1 pursuit (aka basis pursuit) > solutions to inverse problems involving the 1D heat equation as it > describes 1D fluid flow in porous media which is important to understanding > the behavior of shallow reservoirs after fracking. > > The aging curve for references appears to be of that general form so I'd > like to take a crack at seeing how accurately I can forecast the aging > drift. Prior experience and testing solutions of the heat equation > indicate that one can make good predictions for a period equal to the > length of the prior history. > > So if anyone has multiyear data and is willing to share the first half of > the series with me I'll see what I can do. It would be helpful though, to > have the full series for a few references with long histories so I can test > myself before submitting the results for general scrutiny. > > In considering integrated circuit device construction, it seems likely > that both the aging drift and the voltage hysteresis caused by thermal > excursions are related to the different coefficients of expansion of gold, > aluminum and silicon at the wirebond. In particular, I suspect > thermoviscoelastoplastic deformation as the mechanism. However, I have > not seen a photomicrograph of an LTZ1000 reference die showing the bonding > details. If anyone knows of such I'd be grateful for a link. > > For reference, Feynman demonstrated thermoviscoelastic deformation at the > Challenger hearing in his famous C clamp and ice water experiment. In the > case of a voltage reference one must also consider plastic deformation to > be able to account for a permanent change in the value. > > Thanks, > Reg > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. >

I have observed data from a bank of Fluke 732B references that are sent to Fluke every year. These references are intercompared once each week along with 6+ other references that are not sent away. This data is banked for many years. This is in a primary lab that I visited and had my 731Bs calibrated and my 5450A calibrated. The lab is not open to the public. The drift data for this bank of 732Bs can be plotted and allows predicting how accurate the bank is between annual calibrations. You may want to reach out to Fluke directly to see if they would share their data with you for your research project. cheers Brian On Tue, Aug 27, 2019 at 8:48 PM Lou Amadio <lou.amadio11@gmail.com> wrote: > Hi Reg > I have been keeping a spreadsheet on a number of LM399 refs that I have > been running in for over 12 months. > The data consists of non-regular spot checks of the zener (~7v) and 10v > outputs using a Keysight 34461A. > Not sure this it would be of use in your analysis. > Lou > > On Wed, Aug 28, 2019 at 7:16 AM Reginald Beardsley via volt-nuts < > volt-nuts@lists.febo.com> wrote: > > > > > I'm looking for multiyear data from precision voltage references from > > initial power on which includes time-date, temperature and voltage. > > Relative humidity would also be nice if it is available. > > > > I am a retired PhD level oil industry research scientist. I spent a > > number of years heavily involved in the mechanics of materials. I also > > spent several years working on sparse L1 pursuit (aka basis pursuit) > > solutions to inverse problems involving the 1D heat equation as it > > describes 1D fluid flow in porous media which is important to > understanding > > the behavior of shallow reservoirs after fracking. > > > > The aging curve for references appears to be of that general form so I'd > > like to take a crack at seeing how accurately I can forecast the aging > > drift. Prior experience and testing solutions of the heat equation > > indicate that one can make good predictions for a period equal to the > > length of the prior history. > > > > So if anyone has multiyear data and is willing to share the first half of > > the series with me I'll see what I can do. It would be helpful though, > to > > have the full series for a few references with long histories so I can > test > > myself before submitting the results for general scrutiny. > > > > In considering integrated circuit device construction, it seems likely > > that both the aging drift and the voltage hysteresis caused by thermal > > excursions are related to the different coefficients of expansion of > gold, > > aluminum and silicon at the wirebond. In particular, I suspect > > thermoviscoelastoplastic deformation as the mechanism. However, I have > > not seen a photomicrograph of an LTZ1000 reference die showing the > bonding > > details. If anyone knows of such I'd be grateful for a link. > > > > For reference, Feynman demonstrated thermoviscoelastic deformation at the > > Challenger hearing in his famous C clamp and ice water experiment. In > the > > case of a voltage reference one must also consider plastic deformation to > > be able to account for a permanent change in the value. > > > > Thanks, > > Reg > > > > _______________________________________________ > > volt-nuts mailing list -- volt-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. >