Flat signal when rescaling to Volts

[Hanna (Hanna Carla)]

My signal is in uV(microvolts) and when i use raw.apply_function(lambda x: x * 1e-6) and plot i get a flat signal, But when i use the raw.plot(start=100, duration=5, scalings = 'auto') i get a normal plot. I saw other discussions and i’m confused, does MNE automatically rescale the units to Volts?

[agramfort (Alexandre Gramfort)]

what is the input file format?

if your data are in uV eg in .edf then mne will convert it to V on read.

Alex