Elektor Voltage Current Calibrator Project

[KungFuJosh]

Of course. 😉

Test stability once a week or something and see if anything changes.

[Andreas]

Phew, then I would have to let it run for another 3 weeks without a problem....
The text was, however, before the oven, which constantly heats the voltage reference to approx. 55°C - should I still keep it running for so long?

Hello,

I would monitor the voltage output during ageing to see when it stabilizes.

my experiences with MAX6350 (in DIP8-Package).
It may need 50 - 100 days of operation until the ageing slope stabilizes to ~+10 ppm/year under constant conditions.
After some years the slope goes down to ~+5ppm/year.
(in my case they are in a ageing box which is warmer than environment and is heatet to 50 deg C every day during measurement for ~ 80 minutes).

On power outage the Epoxy package of the reference soaks humidity from environment.
After power outage I had a ~5ppm jump which stabilized after some days.

Even under constant temperature you get some seasonal changes due to air humidity.
In my case the humidity goes from ~40%rH in winter to ~70%rH in summer which affects the output.
(see normalized Output from 65kHrs)

with best regards

Andreas