I'm doing low side current measurement over a 0.1ohm resistance. Load is a DC motor powered with 12V.
Cable length between resitor and power supply ground ~60cm
I get a voltage of :
Here is a scope capture with single ended measurement (average down with lower horizontal sensitivity) :
How can we explain this difference? I think it is because of resistance terminal measure point that is 60cm from ground. But how can we precisely explain and quantify it?