To whomever feels qualified to answer this :)

The problem is as follows, three different devices were used to record EEG data and now I want to make sure the obtained files are comparable for two of these devices.

The data is being translated from EDF to Matlab-readable format.

The 3 devices are different in 2 regards, sampling frequency and A/D resolution.

I exclude the difference in sampling rate being relevant here, because it was previously dealt with for 2 of the devices, who were also equal in their A/D resolution.

I do not know, however, how A/D resolution differences should be accounted for, I do know that while A/D resolution is measured in bits, it should not be confused with acquisition mode, which is also measured in bits, but only varies between 16 and 32 bits for all devices we have worked with.

Thanks for any helpful clues and even more for proposed solutions :)