If it’s DC, the easiest way is to use a shunt resistor and measure the voltage across it, and for AC you could use a current transformer ... over shunts and CT’s – accuracy, linearity ...

The KCTS-8000X addresses these critical needs by enhancing the accuracy of current transformer (CT) testing, thereby minimizing billing errors and improving overall operational efficiency.

In the video after the break, [Xavier] goes over the theory of how it all works, but the short version is that you just need to use a Current Transformer (CT) sensor. These little devices clamp ...