This is hart of
winter update and I am also speechless.
How about evaluating my voltage reference among with my divider at 14~15 Celsius as Max indoor.
![Smiley :)](https://www.ittsb.eu/forum/Smileys/default/smiley.gif)
Spesific LT1021 reference chip this is my property and use since 8-2010 at the 8-2020 this will have it ninth birthdays.
In the past eight years I do nothing other than confirming over and over ppm drift due environmental temperature change of my LT1021, and this is 100% according Linear-Technology brand specs.
In my eyes the specific LT1021 chip this worth today 100 times higher of it retail value as new/unused.
This is now fully aged, fully stable, fully predictable ppm/C drift, with a measured Standard Deviation that is second best in my lab.
The most lowest Standard Deviation this were measured at totally analogue portable calibrator, but voltage output repeatability this can not be warranted as there is a ten turns potentiometer controlling the output.
From the other side they are the digitally controlled portable calibrators, the one which I tested has significantly higher Standard Deviation.
In conclusion the autonomous controlled LT1021 chip this is a proven victory in the regard of low Standard Deviation among with fully predictable ppm/Celsius drift.
Speaking of voltage divider resistors, these are Vishay metal film at 0.1%, they are also eight years old, and aged too.
It is interesting that these Vishay resistors seems to not effecting at all the delivered precision due their own not that extremely tight tolerance.
Entire project similes to an cocktail that any Volt-Nut will drink and fully enjoy.