Voltage noise at different sampling frequency:

Actual reading from Bar graph spectrum and Raw wave power

connect 10 K ohm and 100 K ohm resistance

256 point FFT

120 Hz sampling (0..30 Hz)

10 K ohm -> 0.2 µV par spectrum (raw wave 1.4 µVp-p)

100 K ohm -> 0.35 µV par spectrum (raw wave 2.2 µVp-p)

480 Hz sampling (0..120 Hz)

10 K ohm -> 0.3 µV par spectrum (raw wave 2.4 µVp-p)

100 K ohm -> 0.6 µV par spectrum (raw wave 4.5 µVp-p)

960 Hz sampling (0..240 Hz)

10 K ohm -> 0.45 µV par spectrum (raw wave 3.5 µVp-p)

100 K ohm -> 0.9 µV par spectrum (raw wave 6 µVp-p)

1920 Hz sampling (0..480 Hz)

10 K ohm -> 0.65 µV par spectrum (raw wave 4.5 µVp-p)

100 K  ohm -> 1.1 µV par spectrum (raw wave 8 µVp-p)