I am measuring Picotest Kit 1 milliohm resistor using 2 Port Shunt Thru method using Picotest Common Mode Isolator. As shown below above the low frequency range I am measuring a base of approx. 400uOhms instead of 1milliohms. Full 2 Port Calibration is performed. Noise floor was in the 10s of uOhms range. Mounting impedance is of course not accounted for but that should have increased the impedance rather than decrease? What am I doing wrong?
Noise Floor
Better measurement results with the 2 Port Shunt State file provided. Able to see the difference Isolator makes in overcoming the ground loop error at low frequency. But the value is still ~400uOhms. Theoretically, I shouldn't be able to measure a lower resistance value than the real value? So not sure if this 1 milli ohm resistor from the PITK01 kit is actually only 400 uOhms in value.