Scaling from Microvolt to Volt issue

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1

If you have a question or issue with MNE-Python, please include the following info:

  • MNE-Python version: 0.23.0
  • operating system: Windows 10

Greetings,

I having an issue converting from microvolt to volt. After I loaded my CSV file as a Dataframe and then created an info object, I noticed the conversion is wrong.
the data fields of the first channel, e.g., EEG_FP1 is [17.8995, 33.120098, 7.92911]
However, after I run raw.info['chs'][0] I received the following output:

{'loc': array([-0.02884339,  0.10448457,  0.03242402,  0.        ,  0.        ,
         0.        ,         nan,         nan,         nan,         nan,
                nan,         nan]),
 'unit_mul': 0 (FIFF_UNITM_NONE),
 'range': 1.0,
 'cal': 1.0,
 'kind': 2 (FIFFV_EEG_CH),
 'coil_type': 1 (FIFFV_COIL_EEG),
 'unit': 107 (FIFF_UNIT_V),
 'coord_frame': 4 (FIFFV_COORD_HEAD),
 'ch_name': 'Fp1',
 'scanno': 1,
 'logno': 1}

Isn’t 17.8995 supposed to be 1.78995e-5?

Output
Output750×329 7.01 KB

2

EEG data is assumed to be in V, so yes, you need to rescale as mentioned in this answer.

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