How to Record Temco (Temperature coefficient) Voltage reference analysis form

[Kiriakos GR]

When your project of DCV Voltage reference this is now at mature time frame ( circuit testing , voltage reference burn-in) everything completed and tested at minimum within 12 to 24 months.
The next step this is you to record Temco (Temperature coefficient) in to a detailed form that will be your reference.

Now a few details of my own history, originally I did purchase one LT1021-CCN8-10   (10/10/2011) up to date I did update the PCB for this chip three times.
In the last update (6/2019) other than finest capacitors I did add and portion of passive thermal insulation (airtight condition).
Last addition was a 2% 10K Trim pot.

Over the years I gained the awareness that Temco (Temperature coefficient) of the chip it self this is the reason for minor drift over temperature change than the PCB design, capacitors quality, Trim pot specifications.
Even so I did escort LT1021-CCN8-10 with finest passive electronic parts and Trim pot, just for peace of mind.

By throwing entire voltage reference with it case in to my refrigerator, this were cooled down to 10C, then I got it out to 24C room temperature, by recording the voltage output all the way from 10C until to 24C I did realize that manufacturer specification about Temco this is spot-on.      

My used FLK 8846A this is came from Italy 18/2/2019 and now this counts 150 days ( five months),  internal voltage reference this does remarkable work at maintaining DMM Temco down to unmovable.
This opinion it is not based on feelings, because by using as evaluating device FLK 8846A the numbers of Temco drift about my LT1021-CCN8-10 they were verified.
What I succeed here this is due cross-reference evaluation, to verify both devices behavior regarding named specifications. 

Today I am very happy because I have gained true confidence speaking hardware design and operation of my voltage reference.
No other changes will be made again, only detail missing this is a Temco recorded List of actual voltage output of LT1021-CCN8-10 in the range of 15C up to 30C.
For me to complete such a list, this it will require a few months, but as soon this is recorded in full, this will be my own reference report regarding Temco influence of the output.
 
Since 2011 up to 2019 what is matured this is not just my voltage reference Chip but and my own Know-How of what is important when you are using a voltage reference about obtaining usable and measurable facts.
 
Bellow this is sample of the format that I am now using as Voltage reference analysis form, it might become source of inspiration even for you.