Frank, the prospect of this drift data has me salivating. Perhaps make this available in a eevblog thread as well?
Sent from my iPhone > On Aug 28, 2019, at 5:51 PM, Frank Stellmach <[email protected]> > wrote: > > Hello Reginald, > > the LTZ100 has been discussed and investigated thoroughly, over on eevblog. > > https://www.eevblog.com/forum/metrology/ultra-precision-reference-ltz1000/ > > https://www.eevblog.com/forum/metrology/the-ltflu-(aka-sza263)-reference-zener-diode-circuit/ > > There you'll find chip and assembly pictures of the LTZ1000 / A, LTFLU, and > SZA 263 as well. > > > A lot of speculation and investigation about the time, temperature (T.C. > trimming), and hysteretic drift can also be found there. > > It's a very long thread, anyhow. > > Spoiler: The LTZ1000A shows more hysteresis and also random dips, than the > LTZ1000. > > > Then I also can recommend John R. Pickerings famous patent to mitigate > hysteresis effects after temperature excursions. > > The timely drift of the LTZ1000 is linearly affected by the oven temperature > in a quite predictable manner, as you already assumed. > This has already been investigated and quantified by P J Spreadbury in 1990 > "The Ultra Zener .. is it a portable replacement for the Weston cell?". This > basic article I don't find any more on the net, but I have it in my archive. > > The same has been done for the SZA263 and the LTFLU chips inside the 732A/B > references: > > PREDICTABILITY OF SOLID STATE ZENER REFERENCES, by David Deaver, Fluke. > > Myself, I have collected the relative drift data of 4 references, 2x LTZ1000, > 1x 1000A, 1x double SZA263, over about ten years. The first two references > have been running continuously over that time, the other two, only when used, > because these are sitting inside a 3458A, and a 5442A. All their individual > drift rates seem to confirm the mentioned papers. > > Recently, about 2 years ago I started another 5 virgin LTZ1000s, nicely > showing the typical initial timely drift of < 2ppm/year @ 50°C. > > If you are interested, let's discuss how to exchange these data.. I'm very > interested in a drift estimation model for these relative measurements, > equivalent to the Three Cornered Hat method of the time-nuts. > > Frank > > > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
