Calibration multiplier < 1.000

[floreseken]

I wanted to calibrate my cell voltages, so I measured my cells and they all have a slightly lower voltage than the module mesures.

So I need a calibration multiplier with a value less than 1 (0.9987) but this is not possible in the user interface.

I cannot think of a reason why this should not be possible, but I am sure I'm missing something here..

Who can fill me in the details why this is not possible?

Thanks