Isolators SGS-12 series create galvanic isolation between input and output circuits.

Isolator doesn’t need any power supply. 0/4-20 mA current output signal can also be processed into voltage 0/2-10V signal with standard 500Ω load resistance.

Then for class 0.5% it is advised to use voltage input R ≥ 100 kΩ.

Quality of isolation depends on breakdown voltage and also capacity between separated circuits.