8846A AC volts 10mV and below
This is a very crude test but I think it is still valuable.
Rigol 1022 signal generator with sine wave output at 1KHz feeding a 100 Ohm 10 turn pot as a voltage divider.
Adjusted the Rigol impedance setting so the displayed 2V output equals an actual 2V across the 100 Ohm pot.
Adjusted the voltage divider to get 100:1 attenuation, 2V on Rigol = 0.02V out of the voltage divider. (Rigol only goes to 2mVrms)
Shorted inputs give total min max span of 2.73uV with a SD of .7uV (noise floor)
These readings are non zeroed but remember I set my voltage divider ratio with the meter.
meter is in 6.5 digit mode with 100NPLC and analog filter on.
Stepped the Rigol down thru the voltages and and gave each reading about 5 seconds of settling time.
The data has readings from 10 mV down to 2mV that are not plotted. The plotted values are from 0.02mV to 1.0mV
The only thing this shows is the 8846A does not show the nonlinearity that the gellerlabs plots show for the 34401 or 34410 and looks like it would be linear right into the noise floor (Rigol stops at 2mV giving 20µV out of the voltage divider) No accuracy determination can be made from this crude setup but I think the Rigol and voltage divider are linear enough to see if that graph bulge existed or if the meter had a bogus software zero.
I dont know about you but I am impressed
