Preliminary specification for the open DC multimeter

I think to make 2 version of the open DC multi-meter :
- first one (LA stands for low accuracy) with a basic DC accuracy ~ 100 ppm which will be the test bench for the project
- second one (HA stands for high accuracy) with a basic DC accuracy ~ 20 ppm

OSHW DMM Specs

Ranges	Accuracy per year	Resolution	Other characteristics and features
DC Voltage ranges
1V 10V	~ 100 ppm (LA) ~ 20 ppm (HA)	1uV	Input resistance > 1 GOhms Noise floor < 10 uV Auto range
DC Current ranges
5A 1mA	To be estimated later	1mA 1uA	Burden voltage : < 0.02 mV/mA for the 5A range < 0.02 mV/uA for the 1mA range Auto range
Resistance ranges
10KOhms 1MOhms	To be estimated later	0.08 Ohms 8 Ohms	1.25 mA current source 12.5 uA current source 2/4 wire measurement Auto range