The board features a 10V reference , a 2.048V reference and 2 current references that should serve as calibration points.

The design relies on 3 reference ICs(REF102AP,ADR4520,REF200AU) and 3 opamps.

It aims to achieve a 10C +/- 10mV 10ppm/C reference output , a 2.048 reference output with under 1mV initial error at 8ppm/C ,both at 20mA source/sink.

A 100uA source (full range as it's a direct REF200 source) and 200uA source (R_load must be between 10K and 50K to work as expected).

The project is made in KiCAD 6 and the attached prototype photo is the first version missing the ADR4520 output cap,in the prototype version it was soldered near the opamp.
This design error was coirrected in the published version.

This whole board can probably be calibrated at a lab to note the offset and actual drift and then reused at home to calibrate your DVM.